Antihistamine for stomach pain

Antihistamine Treatment for Stomach Acid Breeds Infection

Experts have known for a while that taking antibiotics can up the odds of infection from Clostridium difficile, an illness that causes diarrhea and other unpleasant symptoms. But antibiotics may not be the only culprit. A 2013 study published in the journal PLoS One has discovered that taking antihistamines to reduce stomach acid may also put you at higher risk.

What Is Clostridium Difficile?

Clostridium difficile, also known as C. diff, can also lead to nausea, loss of appetite, and fever. It most commonly strikes the elderly as well as those with health issues and, very commonly, people who are taking antibiotics.

Besides being passed person-to-person, C. diff germs can live for quite some time on objects like bed linens, medical equipment, and door handles — common points of contact. The best defense against its spread is to clean surfaces thoroughly and make sure everyone from patients to health care professionals wash their hands thoroughly.

How Do Stomach Acid and Antihistamines Play Into It?

Stomach acid has an important part in our food digestion. “It begins the process of breaking ingested food down into its components and preparing it for absorption of nutrients in the small intestine,” said William Katkov, MD, a board certified gastroenterologist at Saint John’s Health Center in Santa Monica, Calif. “Stomach acid also acts as an early line of defense against anything we take in that could be harmful, such as bacteria.”

In some people, however, stomach acid can cause ulcers either because of elevated amounts or a sensitivity that makes even regular levels problematic. Many doctors treat it by prescribing antihistamines.

“There is a histamine receptor on certain cells in the stomach that stimulates acid secretion,” said Dr. Katkov. If you can block the histamine receptor with medication — an antihistamine, then you can reduce the acid secretion.

These antihistamines are known as H2 blockers because they bind the receptor on the cells in the stomach called H2 receptors. (The histamine receptor in the stomach is not the same as the one that triggers allergies, and H2 antihistamines are different than antihistamines taken for allergies, such as Benadryl.)

While antihistamines can be helpful when it comes to treating stomach acid issues, researchers in the PLoS One study found an association between antihistamines and Clostridium difficile, and it was even more noticeable in patients who were hospitalized and on antibiotics as well as antihistamines.

What Should a Patient with Stomach Acid Issues Do?

Katkov recommended several steps that people with stomach acid problems can take. “Patients and doctors should use anti-acid medicines cautiously and thoughtfully,” he said. “All medicines can have unanticipated side effects.” Katkov also warned against jumping to conclusions about the study results and believes more research is needed to clarify whether there is a true cause-and-effect relationship between antihistamines and greater risk for C. difficile infection.

Finally, according to Katkov, he encouraged everyone to remember mom’s advice: Whether in the hospital or out-and-about, good hygiene, and especially frequent and thorough hand washing, are key.

Dr Joneja says:

Your symptoms do suggest that dysfunction in the stomach is probably contributing to your symptoms. I wonder what event just prior to the onset in May could have triggered the reaction? Investigation of the possible triggers might give you a better perspective on the options available to you. Infection, especially by Helicobacter pylori and stress, among others might be worth investigating, if you have not already done so.

You are questioning the possible role of histamine in your symptoms, so I am going to take this opportunity to discuss a little of the science behind the connection between stomach problems and histamine, which my patients have often questioned.

Gastric (stomach) acid is required for the first stage of protein digestion. The high acidity of the stomach initiates hydrolysis (chemical breakdown) of proteins in foods. This weakens the linkages between molecules, making the protein more accessible to pancreatic proteolytic (protein degrading) enzymes that act in the small intestine. This breakdown into small polypeptides and amino acids is required before they can be absorbed into circulation. Histamine is responsible for the first stage in the release of gastric acid.

In order to carry out this process, histamine needs to couple to a special receptor on epithelial cells of the stomach, called parietal cells. After activation, the parietal cells secrete hydrochloric acid and intrinsic factor. As in all its diverse roles in the body, histamine must attach to a special receptor molecule on the cell in which it functions. There are 4 known receptor molecules, named H1, H2, H3 and H4, associated with different cells and processes. Parietal cells of the stomach express the H2 receptor.

The symptoms of allergy and inflammation, mediated by histamine, result from histamine coupling with H1 receptors on the reactive cells. Antihistamines, which structurally mimic the histamine molecule, attach to the H1 receptor, effectively blocking the attachment of histamine molecules and preventing their activity. Thus, antihistamines stop the symptoms for which histamine is responsible, but do not inhibit the production and release of histamine. However, antihistamines cannot block the H2 receptor, which has a different conformation, and therefore are of no value in preventing activation of the process of gastric secretion.

Molecules that can couple with the H2 receptor were developed in the 1960s. The first, Cimetidine, was marketed as Tagamet; later Ranitidine (marketed as Zantac) was developed. These are still used to treat conditions such as dyspepsia.

A much more powerful inhibition of gastric acid secretion (up to 99% inhibition) can be achieved with the newer proton pump inhibitors, developed and marketed from the late 1980s and onwards. Proton pump inhibitors intercept the secretion of gastric acid from the parietal cells at a different stage of the process. Whereas histamine receptor blockers prevent the initial stage of acid secretion, proton pump inhibitors block the final stage. They inhibit the enzyme system which is responsible for the movement of acid molecules into the lumen of the stomach. Prilosec (omeprazole) is one of several proton pump inhibitors now commonly used in the treatment of a number of conditions involving the adverse effects of gastric acid such as dyspepsia, esophagitis (oesophagitis) of various types, peptic ulcers and other causes of gastritis.

You do not mention whether the Prilosec helped in the management of your symptoms. You state that you did not like the idea of the proton pump inhibitor, and perhaps would prefer a more “natural” way of control. If Prilosec did help, would you consider trying an H2 blocker such as Zantac or Tagamet in order to reduce the secretion of gastric acid? Have you discussed that with your doctor?

You have questioned the possibility of histamine intolerance contributing to your symptoms. Because of the important role of histamine in gastric acid secretions, it would be a good idea to investigate this further. However, there are no tests which can accurately diagnose histamine intolerance; the most effective method for determining a possible histamine sensitivity is to undertake a histamine restricted diet for a trial period. Follow the directives of foods to avoid, and consume those allowed, for a period of 2-4 weeks. If you experience symptomatic relief you may assume that histamine sensitivity is contributing to your condition and will be able to control your symptoms for the long term. You can find detailed information about histamine sensitivity or intolerance in my books and articles.

Detailed information about which foods are allowed and restricted on the diet can be found in my book, “Dealing with Food Allergies” and the consumer factsheet associated with “The Health Professional’s Guide to Food Allergies and Intolerances”. You can buy all of Dr Joneja’s books here in the UK or here in the US.
As a final note, yogurt and kefir are contraindicated on a histamine-restricted diet since both contain histamine as a result of the fermentation process involved in their manufacture.

March 2016

If you found this article interesting you can find a number of other articles on histamine intolerance both by Dr Joneja and others here, reports on histamine research here and a Q & A section on histamine with Dr Joneja here.

For many, many other articles on every type of food allergy and intolerance ; for coeliac disease and other food related conditions, go here.

To sign up for our FREE fortnightly e-newsletter, go here.

Dr Janice Joneja, Ph.D., RD

Dr. Janice Joneja is a researcher, educator, author, and clinical counsellor with over thirty years of experience in the area of biochemical and immunological reactions involved in food allergy and intolerances. Dr. Joneja holds a Ph.D. in medical microbiology and immunology and was a registered dietitian (RD) – now retired.
She has been a member of the faculty at several Canadian universities, starting her career as an Assistant Professor in the Department of Microbiology, Faculty of Science, and in the Faculty of Dentistry, at the University of British Columbia, Vancouver. Since 2001 Dr. Joneja has been a faculty member in the School of Biomedical and Molecular Sciences, at the University of Surrey, in England, teaching in the M.Sc. course in Nutritional Medicine. For 12 years she was head of the Allergy Nutrition Program at the Vancouver Hospital and Health Sciences Centre.
Dr. Joneja is the author of six books and a dietetic practice manual on food allergy, a textbook on Irritable Bowel Syndrome, and several distance education courses. Her most recent books include “The Health Professional’s Guide to Food Allergies and Intolerances”, “Dealing with Food Allergies”, and “Dealing with Food Allergies in Babies and Children”. Dr. Joneja’s work has been published in peer-reviewed scientific and medical journals, as well as in popular magazines. She is a respected lecturer at universities, colleges and hospitals internationally, and regularly appears on television and radio call-in shows as an expert in her field.
Dr. Joneja is President of Vickerstaff Health Services, Inc., a practice that provides counselling for people suffering from all aspects of adverse reactions to food, and resources for the professionals and care-givers who support them.

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What are H2 blockers?

H2 blockers are a group of medicines that reduce the amount of acid produced by the cells in the lining of the stomach. They are also called ‘histamine H2-receptor antagonists’ but are commonly called H2 blockers. They include cimetidine, famotidine, nizatidine and ranitidine, and have various different brand names.

How do H2 blockers work?

Your stomach normally produces acid to help with the digestion of food and to kill germs (bacteria). This acid is corrosive so your body produces a natural mucous barrier which protects the lining of the stomach from being worn away (eroded).

Upper gastrointestinal tract and acid

In some people this barrier may have broken down allowing the acid to damage the stomach, causing an ulcer. In others there may be a problem with the muscular band at the top of the stomach (the sphincter) that keeps the stomach tightly closed. This may allow the acid to escape and irritate the gullet (oesophagus). This is called ‘acid reflux’, which can cause heartburn and/or inflammation of the gullet (oesophagitis).

The letter H in their name stands for histamine. Histamine is a chemical naturally produced by certain cells in the body, including cells in the lining of the stomach, called the enterochromaffin-like cells (ECL cells). Histamine released from ECL cells then stimulates the acid-making cells (parietal cells) in the lining of the stomach to release acid. What H2 blockers do is stop the acid-making cells in the stomach lining from responding to histamine. This reduces the amount of acid produced by your stomach.

By decreasing the amount of acid, H2 blockers can help to reduce acid reflux-related symptoms such as heartburn. This can also help to heal ulcers found in the stomach or in part of the gut (the duodenum).

Note: H2 blockers are a different class of drugs to ‘antihistamine drugs’ which block H1 receptors in cells that are involved in allergy reactions.

What conditions are they used to treat?

H2 blockers are commonly used:

  • To reduce acid reflux which may cause heartburn or inflammation of the gullet (oesophagitis). These conditions are sometimes called gastro-oesophageal reflux disease (GORD).
  • To treat ulcers in the stomach and in part of the gut (the duodenum).
  • To help heal ulcers associated with anti-inflammatory medication called non-steroidal anti-inflammatory drugs (NSAIDs).
  • In other conditions where it is helpful to reduce acid in the stomach.

At one time they were used as one part of a treatment to get rid of Helicobacter pylori, a germ (bacterium) found in the stomach, which can cause ulcers. However, proton pump inhibitors are now preferred for this use.

How well or quickly do H2 blockers work?

No one H2 blocker is thought to work any better than another. However, the newer group of medicines mentioned above – proton pump inhibitors – also reduce the amount of acid produced by the stomach. They include omeprazole, lansoprazole, pantoprazole, rabeprazole, and esomeprazole. In general, proton pump inhibitors are used first because they are better than H2 blockers at reducing stomach acid. However, if you don’t get on with a proton pump inhibitor (for example, because of side-effects), your doctor may prescribe an H2 blocker.

Generally, H2 blockers are well absorbed by the body and can provide quick relief of symptoms from some problems. For example, heartburn caused by reflux. However, if you are taking them for other reasons, such as to heal an ulcer, it may take longer for the medication to have an underlying effect.

Side-effects of H2-Blockers

Most people who take H2 blockers do not have any side-effects. However, side-effects occur in a small number of users. The most common side-effects are diarrhoea, headache, dizziness, rash and tiredness. For a full list of side-effects and possible interactions associated with your medicine, consult the leaflet that comes with your medication.

Can I buy H2 blockers or do I need a prescription?

You can buy some of these medicines over the counter at pharmacies. They are commonly marketed as medicines for ‘relief of heartburn, indigestion, acid indigestion and excess stomach acid’ – or similar. However, if you need to use an H2 blocker regularly for more than two weeks, you should consult your doctor.

How long is treatment needed?

This can vary depending on the reason for treating you, so speak with your doctor for advice. In some cases your doctor may prescribe an H2 blocker to use ‘as required’. This means you only take it when you need it to relieve your symptoms, rather than every day. In some situations you may be prescribed an H2 blocker to be taken every day.

Who cannot take H2 blockers?

H2 blockers may not be suitable for people with kidney problems or for pregnant or breastfeeding mums. A full list of people who should not take H2 blockers is included with the information leaflet that comes in the medicine packet. If you are prescribed or buy an H2 blocker, read this to be sure you are safe to take it.

Note: taking some H2 blockers can affect how well other medicines work. In particular, tell your doctor if you are taking the blood-thinning medicine warfarin or a medicine for epilepsy, called phenytoin (Epanutin®). You should also tell your doctor if you take theophylline, a medicine commonly used to treat asthma or chronic obstructive pulmonary disease (COPD).

Other considerations

You should consult your doctor if your symptoms worsen, or if you experience any of the following problems which can indicate a serious gut disorder:

  • Bringing up (vomiting) blood. This may be obviously fresh blood but altered blood in vomit can look like ground coffee. Doctors call this ‘coffee-ground vomit’.
  • Blood in your stools (faeces). This may be obvious blood, or it may just make your stools black.
  • Unintentional weight loss.
  • Difficulty swallowing, including food getting stuck in the gullet (oesophagus).
  • Persistent tummy (abdominal) pain or persistent vomiting.

If you are taking antacids you should not take them at the same time as you take your other medication, including H2 blockers. This is because antacids can affect how well other medication is absorbed.

How to use the Yellow Card Scheme

If you think you have had a side-effect to one of your medicines you can report this on the Yellow Card Scheme. You can do this online at

The Yellow Card Scheme is used to make pharmacists, doctors and nurses aware of any new side-effects that medicines or any other healthcare products may have caused. If you wish to report a side-effect, you will need to provide basic information about:

  • The side-effect.
  • The name of the medicine which you think caused it.
  • The person who had the side-effect.
  • Your contact details as the reporter of the side-effect.

It is helpful if you have your medication – and/or the leaflet that came with it – with you while you fill out the report.

Antihistamines are drugs used to block chemicals in the body called histamines. They are commonly used for the relief of allergy symptoms or for gastrointestinal conditions. An allergy reaction causes the release of histamines in the body which is what causes the subsequent itchy skin, hives, runny nose, itchy eyes, or sneezing. There are two subtypes of antihistamines called H1-receptor antagonists and H2-receptor antagonists. H1-antihistamines are used to treat allergy symptoms. Within this group are two generations called the first generation and second generation antihistamines. H2-antihistamines are used to treat gastrointestinal conditions.

Mechanism: H1-antihistamines competitively block histamines from attaching to histamine receptors that are located on nerves, smooth muscle, endothelium, glandular cells, and mast cells. Since histamines causes vasodilation and increase vascular permeability which causes fluid to leak from the capillaries to the surrounding tissues, these H1-antihistamines will block these actions which will stop inflammation and other allergy symptoms. The second generation H1-antihistamines do not cross the blood brain barrier which is why it does not cause drowsiness such as the first generation. The H2-antihistamines block H2 histamine receptors that are found in the gastric acid producing parietal cells of the stomach. Therefore, these antihistamines will reduce the amount of gastric acid being secreted in the stomach.

Uses: The H1-antihistamines are used to treat allergic symptoms such as hives, itchy skin, itchy eyes, runny nose, and sneezing. They are commonly used in dermatology to relieve itchy skin. They can be beneficial for patients with urticaria, atopic dermatitis, contact dermatitis, scabies, and many other dermatologic conditions. Furthermore, first generation H1-antihistamines are sometimes used to treat insomnia due to their side effect profile of causing drowsiness. Some H1-antihistamines have anticholinergic properties such as diphenhydramine and can be used to treat motion sickness. H2-antihistamines are used to relieve gastrointestinal conditions such as gastroesophageal reflux (GERD) or peptic ulcers.

Side effects: The first generation H1-antihistamines such as diphenhydramine (Benadryl) and hydroxyzine (Vistaril/Atarax) causes more side effects such as drowsiness. These drugs should be taken before bedtime and should not be taken before driving or operating heavy machinery. The second generation H1-antihistamines such as fexofenadine (Allegra), loratidine (Claritin), cetirizine (Zyrtec) have less of a sedating effect.

Few of the main side effects from antihistamines include:

  • Dry mouth
  • Dry nasal mucosa
  • Drowsiness
  • Nausea and vomiting
  • Confusion
  • Blurry vision
  • Irritability
  • Headache
  • Dizziness

Cimetidine, a H2-antihistamine, blocks androgenic testosterone at high doses which has the side effect of gynecomastia, which is the enlargement of breasts in a male. Alcohol should be avoided when taking antihistamines.

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Your Annoying Fall Allergy Symptoms Might Not Be Allergies at All

If you wake up mornings with an annoying post-nasal drip and a scratchy cough that lingers all day, you’re probably blaming fall allergies, or maybe an early-season cold.

But when your symptoms persist and don’t respond to antihistamines or cold meds, consider this: you might be battling a type of acid reflux known as silent reflux. The condition really is a thing, even though most people have never heard of it. And it has nothing to do with colds or allergies at any time of the year.

Acid reflux generally implies indigestion, say from eating spicy or acidic foods, or GERD, a closely related yet chronic disorder with several causes. Silent reflux—officially known as laryngopharyngeal reflux or LPR—isn’t characterized by the same symptoms of burning or stomach distress. Instead, of the typical signs, silent reflux has its own symptoms.

RELATED: 7 Home Remedies for Heartburn

Like regular acid reflux, silent reflux still occurs when stomach acid inadvertently flows up to the esophagus. This irritates your throat, causing the cough and post-nasal drip as well as hoarseness in the morning. It can also lead to a chronic need to clear your throat and the sensation that there’s a lump in your throat—because as stomach acid irritates the esophagus, mucous membranes in the throat will produce more mucous than usual, explains Jamie Koufman, MD, director of the Voice Institute of New York and author of Dropping Acid: The Reflux Diet Cookbook & Cure ($18;

Left untreated, silent reflux, like acid reflux, can cause serious problems over time, including asthma, sleep apnea, and even cancer of the esophagus. Unlike seasonal allergies, though, it won’t trigger a runny nose, sneezing, or itchy eyes. Plus, any mucous you’re coughing up will look different. “With someone with seasonal allergies, their discharge is crystal clear and almost looks shards of glass,” says Dr. Koufman. “In a person with reflux, the mucus appears thick and like glue.”

RELATED: 11 Surprising Symptoms of Acid Reflux

So what should you do if you think your symptoms are silent reflux and not autumn allergies or a cold after all? Start with a two-week elimination diet, Dr. Koufman suggests. That means no alcohol, nothing from a can (yep, including seltzer), and cutting way back on dairy and coffee. You should also stick to low-fat, low-acidic foods, and you might want to avoid spicy or fried foods, which are also thought to trigger reflux. Tomatoes, cucumbers, onions, and garlic may also spark reflux symptoms, so eat them sparingly.

If you truly have silent reflux, these diet changes will likely help clear up your symptoms, and you can adopt some of these healthier eating habits for good if they keep silent reflux at bay.

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Tiny tweaks to your regular routine that can help quell silent reflux, just as they can ease other types of the condition. Try not to eat or drink anything too close to bedtime (finish up three hours before you go to sleep, recommends Dr. Koufman). Prop your pillow up when you do hit the hay; sleeping on an incline can help keep stomach acids where they belong.

Consider eating smaller meals throughout the day too, as a fuller stomach is more likely to push acid up the esophagus. And, if you’re carrying around a few extra pounds, look at silent reflux as another convincing reason to lose weight. People who are obese are almost three times more likely than people at a healthier weight to have heartburn and other types of reflux.

Allergies, GERD and Antihistamine Alternatives

Doctors now warn their patients not to take antihistamine medications continuously because of the damage to the sinus membranes from long-term constant use. Health of the membrane tissues is most important to the immune response. A treatment protocol to restore healthy membrane immune responses is needed with all diseases treated with antihistamine medications, which are prescribed to relieve symptoms temporarily. Antihistamines as H2 Receptor Antagonists are also used to block stomach acid production combined with Proton Pump Inhibitors, but now come with warnings that prolonged use is associated with an array of adverse effects, including various nutrient malabsorptions and increased risk for GI infections. Sensible use of these antihistamine medications involves finding complement medicines and treatment to limit the use of the antihistamine medications to short courses taken only as needed. Complementary and Integrative Medicine and Traditional Chinese Medicine (CIM/TCM) provide safe and effective holistic therapies that both relieve symptoms and eventually solve the underlying health problems that create the symptoms. The main effects of CIM/TCM are not just symptom relief, but actual improvement in the underlying health, or the root of the problem.

Temporary relief of allergic symptoms, gastric reflux, ‘heartburn’, stomach ulcers, or skin allergies with antihistamines is not a cure, just a way to suppress symptoms. Ignoring the chronic health problem and just popping multiple pills with side effects every day for the rest of your life is not a good plan. Unhealthy membrane tissues will result in a gradual worsening of the allergic reaction or stomach dysfunction even as the drugs relieve symptoms. Thus the taking of antihistamine medication for a prolonged time on a daily basis will worsen the allergic condition or stomach dysfunction and create more stress for the immune system, possibly contributing to other allergic reactions, as well as difficulties for the immune system in maintaining the health of the gastrointestinal tract and in preventing cancerous mutations. Antihistamine medications are often shown to be ineffective unless combined with decongestants and corticosteroid medications, both of which are problematic with chronic use as well. With daily use for 3-5 days, studies show that sinus decongestants lose effectiveness and can actually cause swelling, and adaptation to decongestants means that increasing dosages are needed to be effective over time. Oral decongestants, like antihistamine medications, can cause a variety of neurological symptoms, such as insomnia, irritability, nervousness, racing heart rates and palpitations, and may worsen high blood pressure, thyroid disease, diabetes, migraines, and negatively interact with antidepressants and anti-migraine medications. The main decongestant is still a variation of pseudoephedrine, a synthetic version of ephedrine, derived from an herb called Ephedra. In Traditional Chinese Medicine, herbal protocol prohibits the prescription of this herb for chronic use. In standard medicine it has been abused without concern for adverse effects.

Antihistamines have also been widely prescribed to inhibit gastric acid secretion. H2, or histamine type 2 receptor antagonists are a class of drugs that includes Tagamet, Cimetidine, Zantac (Rantidine), Pepcid and many other brands, which became the most widely prescribed pharmaceutical medications in the 1980s. The adverse effects of chronic use included hypertension, headache, tiredness, dizziness, diarrhea, constipation and skin rash, and because these H2 receptor antagonists relied on the common catabolic pathway of the liver cytochrome P450, chronic use also could reduce the metabolism of other pharmaceuticals, increasing their serum concentration to toxic levels. This drug contraindication involved warfarin (Coumadin for blood thinning), phenytoin (Dilantin for epileptic seizures), lidocaine (anesthetic), proprolanol and metroprolol (beta-blockers for high blood pressure, tricyclic antidepressants, benzodiazepines (for anxiety), calcium channel blockers (for high blood pressure), sulfonylureas (Glipizide for diabetes), and metrodiazole (Flagyl, an antibacterial), as well as MDMA and alcohol. Obviously, chronic use of these antihistamines and overprescription could lead to many health problems, which were largely ignored. Integration of Complementary Medicine to resolve these health issues requiring antihistamine use to temporarily resolve symptoms was not encouraged, but with the wealth of recent scientific evidence concerning efficacy for these sinus, stomach and skin problems, and the adverse health effects of overuse of antihistamines, this is finally changing.

Histamines are biogenic amines that play an important role in many systems in the body and react with a variety of cell receptor types. Histamines may stimulate bronchioconstriction, vasodilation, gastric acid secretion, immune regulation, regulation of cell life and death (apoptosis), cell development, neural excitability, neuroplasticity (adaption to stress), and regulation of autonomic homeostasis. While the majority of histamine in the body is stored in, and released from, immune cells, such as mast cells and basophils, as well as P-cells, many cells in the body may produce histamine when stimulated, and histamine works in conjunction with a variety of neurotransmitters to cause and regulate many cell functions. In fact, histamine in the brain acts as a neurotransmitter, especially in the regulatory areas, such as the hypothalamus, affecting sleep cycles, diurnal patterns, appetite control, and decreasing acetylcholine, norepinephrine (adrenaline), dopamine, and serotonin, and is grouped with these neurotransmitters as Small Molecule Neurotransmitter Substances. Like other neurotransmitters and hormones, histamine exerts effects that are dependent on the type of receptor it stimulates, rather than having a uniform effect around the body. Because of this complex histamine physiology, the practice of chronic antihistamine use and effects is problematic.

A better way to achieve optimum health and decrease disease related to the histamine metabolism is to help regulate histamine and histamine receptors in the body, and restore histamine homeostasis, or the healthy regulation of histamine release. Much research has been devoted to this subject, and some important herbal chemicals and essential nutrients have been shown to achieve this goal. Quercetin, Bromelain, and Magnesium ascorbate are just 3 of the important herbal and nutrient regulators of the histamine metabolism, and may help one to restore healthy histamine function within a holistic treatment protocol. This histamine balancing approach is applicable to allergic diseases, gastric dysfunction, insomnia, arthritis, atherosclerosis, and even Multiple Sclerosis, and cancers of the lung, breast, ovary and bowel. Of course, resolving the health problems that create the need for antihistamines is important as well. Complementary and Integrative Medicine (CIM) can achieve all of these goals in the same course of treatment.

How antihistamines work

Most of these drugs work by attaching to the cell receptor and preventing the binding to the allergen (e.g. pollen or dust mite) to inhibit the histamine response. Histamine is an amine (derived from ammonia) that is used by cells to stimulate various reactions, such as gastric secretion, bronchial constriction and vasodilation. This combination of fluid secretion, vasodilation and muscle constriction produces the allergic response of nasal mucus congestion to stop the allergen from spreading in the body. Histamine is thus a useful chemical, mainly of our immune cells, but also of the stomach and other tissues. Histamine also stimulates white blood cell production and acts as a neurotransmitter. This is why the antihistamine drugs make one drowsy. While histamine is a valuable chemical tool in our bodies, excess histamine response indicates that the immune system, usually in a localized area, is dysfunctional. Modulating histamine response and improving immune function is thus the logical goal of therapy, not just taking medications that chemically block histamine, constrict blood vessels (decongestants), or supplant natural hormonal immune responses (corticosteroids).

There are 4 types of histamine receptors known and newer drugs are designed to primarily affect one type of histamine receptor to decrease side effects. The allergy medications, Claritin, Allegra etc., primarily block the H1 histamine receptor, which stimulates the membranes, respiratory and organ muscles, skin (itch) and the central nervous system (brain and spinal cord). Other medications, such as stomach acid inhibitors, block the H2 histamine receptors primarily, decreasing stomach secretions, including digestive acids. The other histamine receptors, H3 and H4, decrease other neurotransmitters, such as serotonin, norepinephrine and acetylcholine, and stimulate the immune T cells (thymus), spleen (lymph system), and bone marrow (blood cell production). All antihistamine medications work at all histamine receptors. Types of antihistamines developed to primarily target specific types of histamine receptors do not have their actions confined to this type alone. This is why antihistamine medications have such a variety of side effects.

By looking at the side effects of antihistamines, we see that all the antihistamines, including the stomach inhibitors of histamine, and the antihistamines used to treat eczema, or induce sleep, should not be overused or taken continuously for a prolonged period. Histamine receptor type 2 inhibitors have been largely replaced by proton pump inhibitors (PPI’s), such as Prilosec (omeprazole), Nexium (esomeprazole), Aciphex (rabeprazole), Protonix (pantoprazole), and Prevacid (lansoprazole), to reduce stomach acids, because they have fewer adverse side effects, but studies have shown in recent years that chronic use of these medications could lead to poor stomach function and malabsorption of key nutrients, leading to such health problems as osteopeania and osteoporosis, and some experts have suggested a return to use of antihistamine H2 blockers for patients more at risk for gastric malabsorptions, and of course, some patients, frustrated with decreased effectiveness will combine these type of drugs to control gastric symptoms. Consequently, we see now warnings that patients taking these drugs for a long time have decreased platelets, quadruple risk in pneumonia (T cell deficiency), increased bone fracture incidence (especially when taken with proton pump inhibitors), increased incidence of stomach bacteria such as H. Pylori, poor digestion, increased incidence of GI ulcers, central nervous system problems with neurotransmitter imbalances (insomnia, depression, anxiety etc.). Short term use of antihistamines seems relatively safe. Long term use seems to have too much risk versus benefit. By working to correct the underlying health problems that lead to the symptoms relieved by antihistamines, such overuse and chronic use of these problematic medications can be avoided.

The answer to the problem

Medications are often meant for short term or periodic use to block symptoms, not for daily and long-term use, and blocking the mechanism of the symptoms of the health problem does not resolve the health problem itself, it just temporarily relieves symptoms. This is especially true for antihistamines, which counters a healthy natural immune response in our bodies, the histamine response. Unfortunately, with excessive stimulation of the histamine response, and/or poor regulation of the histamine metabolism, the swelling induced by histamine becomes problematic, producing unwanted symptoms. The key to resolving this problem does not lie in just taking antihistamines for the rest of your life, but in proactively fixing the underlying health problem and sometimes in aiding healthy regulation of histamine metabolism. The patient is responsible to try to get themselves healthier and thus reduce the cause of these symptoms, and reduce the dependency on antihistamine drugs. The prescribing M.D. is not focused on improving the health of the patient, only in solving the symptoms by providing antihistamines, and often does not inform the patient that FDA and pharmaceutical guidelines state that antihistamine drugs are intended only for temporary use to relieve symptoms, and come with various adverse health effects with chronic use. The patient should seek medical care from providers that are trained to restore the health of the body to correct the underlying cause of symptoms related to the histamine response. The physician practicing Traditional Chinese Medicine, called the Licensed Acupuncturist, can help you get healthier to get rid of the cause of these symptoms. If needed, this Complementary and Integrative Medicine physician can help regulate the histamine metabolism, and help resolve adverse health effects from overuse of antihistamines as well. This is sometimes a laborious process, but well worth it in the end. Your health improves.

With allergic problems and sinus congestion and drainage there are two mechanisms that must be addressed: 1) the immune response and the allergens, and 2) the vasomotor nerve response that is dysfunctional and stimulates the chronic clear fluid drainage and sensation of congestion that makes one feel ‘foggy’. There are a number of things the patient and physician must work on:

  • Aromatic herbs will stimulate to decrease congestion. Improved circulation and responsiveness of the membranes, our chief immune defense, needs to occur when chronic or acute symptoms of congestion occur. By stimulating the cells and tissues, opening the flow, and providing increased bioelectric potential, the membrane health and function improves. Aromatic is a term that defines molecules with a ring of organic atoms that provides for increased interaction of electrons with surrounding molecules. Histidine, the aromatic amino acid that provides our histamine, is just one of four aromatic amino acids, along with phenylalanine, tyrosine and tryptophan, and many herbs contain potent aromatic hydrocarbons that are the main active chemicals.
  • Antiviral and antifungal herbs will decrease allergen effects. Pharmaceuticals still do not have any workable medications to treat viral and fungal disease safely and effectively. Plants have evolved natural antiviral and antifungal chemicals for millions of years in Mother Nature’s Laboratories, and humans have used these plant chemicals for their health maintenance for millions of years as well, yet now we are suddenly ignoring this valuable treatment potential, pretending that it suddenly quit working.
  • Immune stimulating herbs will cause a healthier immune response. The immune system should be able to counter any threat. If it is not doing its job, it may need some help. Corticosteroid medications are well known to be immune suppressant, yet they are prescribed routinely and for long-term therapy when treating a deficient immune responsiveness. This is illogical, yet is routinely accepted as standard care by both patients and physicians.
  • Decrease in exposure to allergens, especially as you sleep, will decrease your sensitivity. Dust mites in fresh flaked skin are a major allergen, as is pet dander, mold and mildew, and the immune system focuses on the internal organs during sleep, and less on the outer membranes. Simple habits, such as shaking the bedding out each morning, keeping pets off the bed, providing fresh air during the day in the bedroom, and checking the home environment for sources of chronic internal damp growth of pathogenic molds and mildews may do more than any medication to relieve chronic allergic symptoms.
  • Improvement in the digestive health will insure better balance and absorption of necessary nutrients and take stress off of the immune system. Much research now demonstrates that allergens and antigens entering the blood circulation via the gastrointestinal tract often are part of the cause of sinus, bronchial and skin allergic reactions and excess histamine response.
  • Improved neuroendocrine health will give one a better control over the vasomotor response. Acupuncture stimulation, if performed correctly, will accomplish much in this regard, and works synergistically with herbal and nutrient medicines that provide a better bioavailability of neurotransmitters and hormones. A wealth of research now proves that acupuncture stimulation and electroacupuncture achieves significant stimulation and modulation of the neurohormonal control centers of the brain.
  • Histamine balance and improved regulation of histamine metabolism may be achieved, if needed. When the chronic allergic response, and chronic use of antihistamines, occurs, the complex immune feedback system of histamine regulation, as well as the healthy capability to produce histamine within immune cells of our membranes, may be damaged. Research has proven that various herbal and nutrient chemicals, such as Quercetin, Bromelain, Magnesium ascorbate (a type of Vitamin C), and acupuncture stimulation, can restore the healthy histamine metabolic balance needed to insure maintenance of membranes and immune function.

With problems related to gastric acid, GERD, and gastric dysfunction, the holistic physician may help restore gastric function while improving the health of the intestinal membranes, immune functions, and natural biotic homeostasis. A number of natural medicines are researched to achieve this goal, including bioidentical gastric hormones and precursors to gastric secretions, herbs to reduce overgrowth of microbial parasitic infections, probiotics, a variety of studied enzymes, herbs to restore the function of the bowels, aids to intestinal membrane health, deficient nutrient molecules involved in the diseases, and even acupuncture. Simply continuing to use histamine inhibitors to control gastric symptoms does not restore health.

While working on the underlying health to common diseases involving histamine, especially allergic problems and gastric dysfunction, the holistic physician may also utilize medicines to help restore histamine balance, or homeostasis, such as quercetin, bromelain and magnesium ascorbate. A holistic regimen is not as simple as taking a pill, but the benefits are great and the ill effects are next to nothing. The end result of all of this work is a healthier, more productive, more energetic and happier patient. It is worth it.

Histamine Balance and Regulation

The histamine response is an important and essential mechanism in the human body, important for regulation of the inflammatory responses as well as gastric function and digestion, and restoration of the histamine response and metabolism is obviously desired over simple blocking of histamine. In recent years, more and more warnings of adverse effects of chronic antihistamine use have led to a great interest in achieving histamine balance and homeostatic regulation, and a number of common herbal and nutrient chemicals have been found to achieve this restoration of histamine metabolism. Studies have also shown that acupuncture stimulation is very effective at modulation of histamine response. These studies have demonstrated that short courses of acupuncture and herbal/nutrient medicine are indeed effective to treat allergies, GERD and skin conditions.

Quercetin is a much studied active chemical in a number of Chinese herbs, and minute amounts are found in many common foods as well. Quercetin has been found to moderate excess histamine response by inhibiting excess expression of histamine type 1 receptors when allergen and antigen stimulation is excessive, or when the immune system responds with hypersensitivity. Quercetin is thus a modulating, rather than blocking antihistamine. Added benefits of quercetin include mild bronchodilation, antioxidant effects, and anti-inflammatory effects. Quercetin is usually used in a formula of herbal and nutrient medicines to achieve the effects. Chinese herbs that contain quercetin include Luo bu ma (Apocynum venetum), which is used to aid bronchial health and function, lower blood pressure, and benefit liver health, Sang ji sheng (Loranthus), which is widely used to support liver and kidney health, strengthen muscles and bones, treat cardiovascular disease, and help lower blood pressure, and has been found to inhibit TNF-alpha and IL-1 beta inflammatory cytokines often implicated in chronic inflammatory diseases, Di er cao (Hypericum japonicum, related to Saint John’s Wort), and Man shan hong (Rhododendron dahuricum), an antiasthmatic, antitussive, expectorant. Quercetin is also found in foods, such as shallots and steel cut oats, as well as tea (Camellia sinensis), Neem and evening primrose leaf extract. The beneficial effects of quercetin are now well studied and documented, but medical institutions in the United States continue to imply that quercetin in only found in foods, and omit its concentrated presence in these commonly used Chinese herbs.

Resources: Additional Information and Links to Studies

NOTE: many more studies are available with links on separate articles on this website on Allergies and GERD

  1. A succinct summary of problems with chronic antihistamine medications to block stomach acid, called H2 receptor antagonists, is presented by Dr. Jim Howenstine M.D.:
  2. A 2005 meta-review of all published studies of the efficacy of using antihistamine H2 receptor antagonists and Proton Pump Inhibitors just as needed, and not continuously, by experts at the Queen Elizabeth Health Scences Center in Halifax, Nova Scotia, Canada, found evidence that intermittent use as needed was effective for control of heartburn and gastric reflux (GERD), but was insufficient to control esophagitis. Use of Complementary and Integrative Medicine could make this work for all patents, though:
  3. A 2014 randomized controlled study at the Henan University School of Medicine, in Henan, China, found that a common Chinese Herbal Formula, called Xuan fu Dai Zhe Tang, provided significant improvement in control of acidity and improvement of esophagitis in laboratory animals, with improved tissue health of the gastric and esophageal mucosa. The herbs in this classic formula are Inula (Xuan fu hua), Hematite (Dai zhe shi), Pinellia (Ban xia), Codonopsis (Dang shen) along with Ginseng, Ginger, Jujube and Glycerine (Gan cao). Such studies confirm the efficacy of CIM/TCM therapies, and work synergistically with acupuncture to improve gastric health and function:
  4. A 2012 randomized controlled human clinical trial of 480 patients, at the Xinjiang Medical University, in Henan, Weihui, China, showed that a standard Chinese herbal formula controlled gastric reflux and benefited gastric mucosal health and function well, with the addition of acupuncture therapy added improving the effectiveness. The Chinese herbs in the formula tested, Zhi Zhu Kuan Zhong Tang are are Bai zhu, Zhi shi, Chai hu and Shan zha, which are used in many formulas to treat gastric symptoms and pathologies, :
  5. A 2004 report by the esteemed Mayo Clinic, in Rochester, Minnesota, U.S.A. noted that herbal medicine present a sound therapy to treat stomach acid pathologies, or dyspepsia, but need more clinical trials to confirm these effects. H2 receptor antagonists, Proton Pump Inhibitors and other drugs are noted as widely used but still show limited benefits:
  6. Chronic disruption of histamine homeostasis is now linked to cancers, Multiple Sclerosis, and an array of other diseases. Here, researchers at Semmelweiss University, in Budapest, Hungary, show how histamine is involved in the pathogenesis of several cancers, and even adrenal cancers, characterized by reduced histamine biosynthesis affecting the b balance of histamine receptor types.
  7. Newer classes of antihistamines were developed due to the alarming adverse effects of chronic use of older types of anthistamines, but many of these older antihistamines, such as Benadryl, are sold off the counter without prescription, and cause a large number of injuries related to CNS sedation, and reduced quality of life over time. Awareness of such adverse effects by the individual patient is important:
  8. Research in 2013, at Columbia University, New York, New York, U.S.A. showed how the Chinese herbal chemical quercetin could effectively relieve asthma symptoms, acting as a bronchodilator, and modulating histamine response, even as an inhaler. Such novel use of Chinese herbal chemistry could significantly reduce the problematic dependency on standard asthma inhalers, which contain a combination of antihistamine, adrenergic block, and corticosteroid.
  9. Research in 2013, at the University of Tokushima Institute of Health Biosciences, Tokushima, Japan, found that the Chinese herbal chemical Quercetin inhibits excess expression of the histamine receptor type 1 by suppression excess protein kinase signaling pathways. This study found that use of quercetin for 3 weeks relieved sinus allergy symptoms and excess expression of histamine receptors effectively in laboratory animals:
  10. A 2015 study at the Yantai Blood Center in Shandong, China, found that an active chemical in the Chinese herb Cordyceps (Dong chong Xia cao), daucosterol, exerted potent inhibition of histidine decarboxylase, inhibiting histamine to treat allergic transfusion reactions:
  11. A thorough informative article on allergic rhinitis from the University of Maryland Medical Center highlights the fact that sinus decongestant, antihistamine, corticosteroid drugs should not be used for more than 3 days in a row, or worsening of the overall condition may occur – the site also outlines the importance of integrating a holistic regimen to treat allergies – a position finally adopted by standard medicine. Paying attention to the details in the disease will result in much greater success in treatment:
  12. A 2006 report from the Swiss Institute of Allergy and Asthma Research Center, in Davos, Switzerland, explains that histamine is not and unwanted and pathological chemical, but an essential mediator of both acute and chronic inflammation and hypersensitivity responses, regulation the homeostatic mechanisms that protect us from allergens and hypersensitivity. Histamine also has been found to balance the Th1 and Th2 (T-helper cell types), an essential aspect of autoimmune responses. While the total immune histamine metabolism is still not entirely understood in medicine, we now know that simply blocking the production of histamine is not a sensible approach, except when necessary in acute situations to control symptoms. Obviously, restoring histamine metabolism is a much more intelligent approach to many health problems related to swelling, bronchial constriction, and manifestations of skin disease:
  13. A 2012 study at the Technical University of Munich, in Germany, Department of Dermatology and Allergy, found that common acupuncture (VA or verum acupuncture) was as effective as the antihistamine cetirizine for reduction of hypersensitivity reactions and itch:
  14. A 2010 study at Osaka University School of Medicine, in Osaka, Japan, found that a common treatment with acupuncture, electrical stimulation at the points ST36 and ST37 for relief of pain, worked partly be exerting an anthistamine or histamine modulating effect in the brain. Pain stimulus in laboratory animals induced increased histamine, dopamine and adrenaline, and these increases in histamine and dopamine were completely reversed by the acupuncture stimulation, while the adrenaline level was not affected:

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