- Dose-Response Studies
- About tetracycline
- Before taking tetracycline
- How to take tetracycline
- Getting the most from your treatment
- Can tetracycline cause problems?
- How to store tetracycline
- Important information about all medicines
- What is tetracycline?
- Important information
- Before taking this medicine
- How should I take tetracycline?
- What happens if I miss a dose?
- What happens if I overdose?
- What should I avoid while taking tetracycline?
- Tetracycline side effects
- What other drugs will affect tetracycline?
- Further information
- More about tetracycline
- Consumer resources
- Professional resources
- Related treatment guides
- What is tetracycline used for?
- 💡Key facts about tetracycline
- How does tetracycline work?
- Who shouldn’t take tetracycline?
- Dosage: How do I take tetracycline and how often?
- Can I drink alcohol while taking tetracycline?
- What are the side effects of tetracycline?
- Can I take other medicines with tetracycline?
- tetracycline (Rx)
- Dosage Forms & Strengths
- Chronic Bronchitis, Acute Exacerbation
- Moderate-to- Severe Acne
- Uncomplicated urethral, endocervical or rectal infections
- Other Infections
- Other Infections (Penicillin-Resistant)
- Dosage Modifications
- Dosing Considerations
- Related posts:
Tetracycline hydrochloride is a prescription antibiotic used to treat a wide range of infections.
It’s effective against a broad spectrum of bacteria, as well as other organisms, including some protozoan parasites.
Tetracycline has commonly been used to treat acne and other skin infections; respiratory tract infections such as pneumonia; genital and urinary infections; and Helicobacter pylori (the bacteria that can lead to stomach ulcers).
It’s also sometimes used for treating Lyme disease and for preventing anthrax infections.
The first drug in the tetracycline family, chlortetracycline, was introduced in 1948.
Tetracycline and Antibiotic Resistance
Overuse of tetracycline (and other antibiotics) in humans and farm animals has allowed some bacteria to build up a resistance to antibiotics.
The development of these so-called “superbug” bacteria limits the number of infections that antibiotics such as tetracycline can treat. (Partly as a result of antibiotic resistance, tetracycline is prescribed less often today than other, more effective antibiotics.)
Doctors are now strongly advised to prescribe tetracycline only when there is proof, or a strong suspicion, that bacteria – not a virus – is causing an infection.
Since tetracycline does not work for colds, influenza (flu), or other viral infections, if you take it for these conditions, you may be promoting the development of drug-resistant diseases while doing nothing to help your illness.
Tetracycline for Dogs and Other Animals
Tetracycline is prescribed for dogs, other household pets, and livestock. Low doses are commonly fed to farm animals to promote their growth.
It’s often used in dogs and cats to treat leptospirosis, toxoplasmosis, mycoplasma, and psittacosis. Tetracycline is also effective in animals that have tick-borne infections, such as Lyme disease, ehrlichiosis, and Rocky Mountain spotted fever.
Before taking tetracycline, you should tell your doctor if you have or have ever had:
- Hay fever
- Kidney disease
- Liver disease
You should tell your physician that you are taking this medication before having any type of surgery, including dental surgery.
Tetracycline can cause false readings on tests for sugar in urine. If you have diabetes, you should talk to your doctor about this possibility before altering your diet or changing your diabetes medication dosage.
You should not take this medication after it expires. Consuming expired tetracycline can lead to a dangerous syndrome that can result in kidney damage.
Tetracycline and Children
When this medication is used to treat children up to age 8, it can cause lifelong tooth discoloration. It can also affect a child’s growth.
Tetracycline should therefore not be used in children under age 8 unless directed by a doctor.
Pregnancy and Tetracycline
Tetracycline is a pregnancy category D drug. Studies show the medication can impair the development of bones in infants. Use during pregnancy can also cause lifelong tooth discoloration in your child.
This drug should not be used during pregnancy unless the benefits outweigh the risks.
Tetracycline is secreted in breast milk and may affect bone and tooth development in a nursing infant. Women should not use this medication while breastfeeding.
Extended release versus immediate release. Clinical and pharmacokinetic data with multiple formulations of minocycline IR indicate that the occurrence of vestibular AEs correlates with the dissolution rate and Cmax of minocycline.27 Additional data suggest that vestibular AEs are more frequent in patients with lower body weight unless the dose is adjusted to body weight.25 The occurrence of vestibular AEs appeared to be related to a rapid influx of minocycline into the blood, which produces high spikes in serum concentrations following administration of minocycline IR.27 These spikes likely facilitate penetration of the blood-brain barrier, potentially increasing the risk of vestibular AEs. The ER formulation of minocycline slows the rate of drug release and systemic drug exposure. A weight-based dosing schedule was developed to minimize the impact of differences in body weight on treatment outcomes and AEs.
Rate of dissolution. In a randomized, multiple-dose, crossover trial,29 28 healthy adults received minocycline ER 135mg or minocycline IR 100mg once daily for six days, before undergoing 14-day washout and switching to the alternative treatment. Blood assays for determination of pharmacokinetic parameters were assessed before and for 72 hours after the final dose. Twenty-seven subjects completed the study. Minocycline ER Cmax occurred later (3.5–4h) than minocycline IR Cmax (2.25–3h). At steady state, minocycline ER Cmax was lower than minocycline IR Cmax (2.63µg/mL vs. 2.92µg/mL, respectively). The mean minocycline ER AUC from 0 to 24 hours was lower than that of minocycline IR (33.32µg·h/mL and 46.35µg·h/mL, respectively).
Although the sample size for this study was small, the results nonetheless provide useful information about the mean and median values for a population, but are of limited utility for characterizing individual patient variability within a population. Interpatient variability can account for differences in individual response to an antibiotic compared with the anticipated response for the majority of the population. As the classic S curve of dose response predicts, a patient who absorbs the drug poorly may experience poor efficacy at a dose that is otherwise effective for the median of a population; whereas, a patient who absorbs the drug with unusual rapidity may experience AEs at a dose that is otherwise well tolerated by the median of a population.
Important differences between minocycline ER and IR with respect to AUC and Cmax can be displayed to great effect using a box-plot analysis, wherein the upper border of the box represents the value of a pharmacokinetic parameter for the 75th percentile, the lower edge the 25th percentile, and the midline of the box the median of a population. The resulting box gives the range for 75 percent of the study population. The bars above and below the box represent the highest and lowest values not more than 1.5 times the range within the box. Outliers include patients with pharmacokinetic values greater than 1.5-fold above or below the upper or lower limit of the intrabox range but less than threefold times that distance. Extreme outliers have values threefold above or below the range within the box plot.
Figure 1 is a box-plot display of the Cmax data for the two minocycline formulations derived from the 28-subject study described above.41 The box for the ER formulation is smaller than that of IR formulation; 75 percent of subjects receiving minocycline ER have a Cmax between 2 and 3µg/mL compared with a broader range for subjects receiving the IR formulation. With the IR formulation, there was one (3.7%) extreme outlier with a Cmax of 8.9µg/mL. In addition, there were two subjects (7.4%) with values >6µg/mL with the IR formulation compared with two subjects (7.4%) with values >4µg/mL with the ER formulation. There were no extreme outliers following administration of minocycline ER. Spearman rank correlation (P<0.001) showed a significant degree of concordance in Cmax levels for the two formulations. For example, the extreme outliers who had the lowest and the highest Cmax with the IR formulation also had the lowest and the highest Cmax with the ER formulation.
Day 6 box-plot analysis of maximum plasma concentrations (Cmax) with minocycline IR and ER formulations (see detailed explanation in manuscript); IR=immediate release; ER=extended-release
Figure 2 is a box-plot display of the steady-state AUC over a 24-hour period. ER minocycline showed a very small box compared with the IR formulation.41 The IR formulation had one (3.7%) extreme outlier for high absorption; this subject was the same person who was also an extreme outlier for Cmax with the IR formulation and also had the second highest AUC with ER minocycline. The subject with the lowest AUC with minocycline IR also had the lowest AUC value with the ER formulation. The Spearman rank correlation was again significant (P<0.001), indicating a high degree of concordance between AUC and the ER and IR formulations.
Day 6 box-plot analysis of area-under-the curve (AUC) with minocycline IR and ER formulations (see detailed explanation in manuscript); IR=immediate release; ER=extended-release
Collectively, these data suggest that patients receiving either minocycline formulation would be expected to derive therapeutic benefits from therapy but that patients treated with minocycline ER would be less likely to have extreme elevations in Cmax and AUC and therefore be more likely to better tolerate therapy. Only one subject had a low AUC following administration of minocycline ER. This subject might be predisposed to exhibit a poor clinical response with the ER formulation because of lower GI absorption. In cases with suboptimal response, assuming good compliance and an adequate treatment duration, an escalation of the daily minocycline ER dose may be required because the patient may be an innate “low minocycline absorber.”
Effects of food. In a small randomized, single-dose crossover trial,29 24 healthy adults (12 women) aged ≥18 years received consecutive single oral doses of minocycline ER 135mg under fasted conditions and after a meal that included dairy, separated by a seven-day washout period. The population included African-American (n=12), Caucasian (n=10), Hispanic (n=1), and Asian (n=1) subjects.42
The tmax for minocycline ER was 3.52 hours under fed conditions and 3.69 hours under fasted conditions. Cmax was 1.85µg/mL under fed conditions and 1.84µg/mL under fasted conditions. These data suggest that food intake has little effect on the absorption of minocycline ER (<1% decrease in absorption under fed conditions) (Figure 3). In contrast, there was an 11-percent reduction in minocycline IR absorption and a 24-percent reduction in doxycycline absorption after a meal. The AUC of minocycline ER was 38.4µg/mL·h under fed conditions and 39.1µg/mL·h under fasted conditions. Terminal half-lives under fed and fasted conditions were 16.6 and 16.3 hours, respectively, for minocycline ER.42
Effects of food on GI absorption and percent reduction in maximum plasma concentrations (Cmax) after single doses of minocycline ER, minocycline IR, and doxycycline(see detailed explanation in manuscript); GI=gastrointestinal; ER=extended-release; IR=immediate-release
Weight-based dosing. In a small, blinded, crossover study, 32 female patients (aged 21–55 years) received minocycline ER or generic minocycline IR for four days before undergoing a 14-day washout and switching to the alternative treatment. Both minocycline formulations were administered on a weight-based schedule: 100mg/d, 50–69kg (n=20); 150mg/d, 70–89kg (n=7); and 200mg/d, ≥90kg (n=5). Minocycline IR was released from its capsule more rapidly (90% within 45 min) than minocycline ER (30–53% in 1h, 54–84% in 2h, and >85% in 4h).43
There was no difference between the two minocycline formulations with respect to general AEs (e.g., headache, malaise) or GI AEs. However, vestibular AEs (e.g., vertigo, dizziness, blurred vision) were significantly less frequent with ER minocycline (P=0.0003). In all, five vestibular AEs were reported with minocycline ER and 27 were reported with minocycline IR.43
In a Phase II dose-ranging study,14 233 patients aged 12 to 30 years with acne vulgaris were randomized to receive minocycline ER tablets 1, 2, or 3mg/kg or placebo once daily for 12 weeks. The efficacy of minocycline ER was positive across all of the weight-based dosing groups. Percentage reductions in inflammatory lesions were 56.8 percent in the 1mg/kg group, 49.3 percent in the 2mg/kg group, and 46.6 percent in the 3mg/kg group. The difference between minocycline ER 1mg/kg and placebo was significant at Week 12 (P=0.015 vs. placebo). The overall occurrence of any AE was similar in patients in the 1mg/kg group (53%) and 2mg/kg (56%) groups and slightly higher in the 3mg/kg group (65%). The incidence of acute vestibular AEs increased with dose from 10.2 percent in the 1mg/kg group to 16.4 percent in the placebo group, 23.7 percent in the 2mg/kg group, and 28.3 percent in the 3mg/kg group. AEs leading to treatment discontinuation were reported less frequently in the 1mg/kg group (n=4) than in the 2mg/kg (n=7) or 3mg/kg groups (n=14). These results indicated that efficacy, defined as reduction in inflammatory lesions, was similar across dosage ranges, but that use of a lower dose based on body weight resulted in fewer acute vestibular AEs.
A pooled analysis of patients treated with minocycline ER 1mg/kg as monotherapy in the aforementioned Phase II dose-ranging trial and in two Phase III trials was conducted to characterize efficacy and tolerability in a total of 1,038 patients with moderate-to-severe acne vulgaris. In these trials, 674 patients received minocycline ER 1mg/kg once daily and 364 received placebo.13 Minocycline ER was administered in a 45mg dose to patients weighing 45 to 59.54kg, 90mg to patients weighing 60 to 90.45kg, and 135 mg to patients weighing 90 to 136.36kg.
Minocycline ER therapy resulted in a mean 45.5-percent reduction in inflammatory lesion counts compared with a 32.4-percent reduction in the placebo group (P<0.001). Evaluator’s Global Severity Assessment ratings indicated that 16.6-percent of patients in the minocycline ER group were “clear” or “almost clear,” compared with 8.7 percent in the placebo group. Noninflammatory lesion counts decreased by 14.9% and 6.3% in the minocycline ER and placebo groups, respectively.13
Adverse events were reported by similar percentages of the minocycline ER (56.2%) and placebo (54.1%) groups. Vestibular AEs generally occurred with similar frequency in patients treated with minocycline ER and placebo: nausea (9.5 vs. 11.3%, respectively), vomiting (2.1 vs. 2.5%), tinnitus (1.5 vs. 1.4%), and vertigo (1.2 vs. 0.8%). Urticaria occurred infrequently (1.5 vs. 0.3%).13 Dizziness was reported with minocycline ER more frequently than with placebo (8.8 vs. 4.7%), but the incidence was generally lower than that reported with minocycline IR.21 Collectively, these results support the hypothesis that an ER minocycline formulation administered using a weight-based dosing schedule can improve tolerability. The results also suggest that efficacy when treating acne may be maintained by using weight-based dosing of minocycline ER, likely due to its high lipophilicity.
|Type of medicine||A tetracycline antibiotic|
|Used for||Bacterial infections; acne; rosacea|
Tetracycline is an antibacterial medicine. This means that it stops infections caused by germs (bacteria). It is prescribed as a treatment for infections such as chest infections, mouth infections, sexually transmitted infections, and infections resulting from some types of bites.
Tetracycline is also prescribed for some longer-term skin conditions, such as acne and rosacea.
Before taking tetracycline
Some medicines are not suitable for people with certain conditions, and sometimes a medicine can only be used if extra care is taken. For these reasons, before you start taking tetracycline it is important that your doctor (or dentist) knows:
- If you are pregnant or breastfeeding. You should not take tetracycline.
- If you are under 12 years of age. Tetracycline should not be taken by children.
- If you have any problems with the way your liver works, or if you have any problems with the way your kidneys work.
- If you have an inflammatory condition called systemic lupus erythematosus (also called lupus, or SLE), or if you have a condition causing muscle weakness, called myasthenia gravis. Tetracycline can make these conditions worse.
- If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.
- If you have ever had an allergic reaction to a medicine.
How to take tetracycline
- Before you start the treatment, read the manufacturer’s printed information leaflet from inside the pack. It will give you more information about tetracycline, and will also provide you with a full list of the side-effects which you could experience from taking it.
- Take tetracycline exactly as your doctor tells you to. If you have an infection it is likely you will be asked to take three or four doses a day, and if it is for acne or rosacea you will be asked to take two doses a day. You will be prescribed one or two tablets to take for each dose. Your doctor or pharmacist will tell you which dose is right for you, and this information will also be printed on the label of the pack to remind you about what was said to you.
- Try to take your doses around the same times of day each day. This will help you to remember to take them regularly. Space out your doses evenly throughout the day.
- Take the tablets when your stomach is empty. This means taking your doses one hour before you eat food, or waiting until two hours after you have eaten. It is also important that you do not drink milk within two hours (either before or after) of taking tetracycline. This is because both food and milk can reduce the amount of medicine absorbed by your body, making it less effective in fighting infection.
- The tablets can cause throat irritation. To prevent this, you should swallow the tablets with a large drink of water. Sit upright or stand up to take the tablets. Try to avoid taking tetracycline just before lying down, or at bedtime.
- If you forget to take a dose, take it as soon as you remember. Try to take the correct number of doses each day, but do not take two doses together to make up for a missed dose.
Getting the most from your treatment
- Your course of treatment is likely to last for a week or so if you are being treated for an acute infection. If you are taking tetracycline for acne or rosacea, your treatment could last for several months. It is important that you keep taking the tablets until the course of treatment is finished (unless you are told to stop sooner by a doctor).
- If you buy any medicines, check with a pharmacist that they are suitable to take with tetracycline, as a number of ‘over-the-counter’ remedies can interfere with it. In particular, do not take indigestion remedies, or supplements containing iron, magnesium, or zinc at the same time. This is because tetracycline combines with these things, which makes it less effective. If you need to take an antacid or any of the supplements mentioned, make sure you leave at least two hours before or after taking tetracycline before you have them.
- Some people develop thrush (redness and itchiness in the mouth or vagina) after taking a course of an antibiotic. If this happens to you, speak with your doctor or pharmacist for advice.
- Tetracycline could cause your skin to become more sensitive to sunlight than usual. Avoid strong sunlight and sunbeds until you know how your skin reacts.
- This antibiotic can stop the oral typhoid vaccine from working. If you are due to have any vaccinations, make sure the person treating you knows that you are taking this medicine.
Can tetracycline cause problems?
Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the ones associated with tetracycline. The best place to find a full list of the side-effects which can be associated with your medicine, is from the manufacturer’s printed information leaflet supplied with the medicine. Alternatively, you can find an example of a manufacturer’s information leaflet in the reference section below. Speak with your doctor or pharmacist if any of the following continue or become troublesome.
|Tetracycline side-effects||What can I do if I experience this?|
|Stomach upset, tummy (abdominal) pain||Stick to simple foods – avoid fatty or spicy meals|
|Diarrhoea||Drink plenty of water to replace lost fluids. If this continues or is severe, speak with a doctor|
|Headache||Drink plenty of water and ask your pharmacist to recommend a suitable painkiller. If the headaches continue, let your doctor know|
|Blurred vision||Do not drive and do not use tools or machines while affected. If it continues, speak with your doctor|
Important: tetracycline can occasionally cause allergic reactions, such as a skin rash. Speak with a doctor as soon as possible if this happens to you.
If you experience any other symptoms which you think may be due to the tablets, speak with your doctor or pharmacist for further advice.
How to store tetracycline
- Keep all medicines out of the reach and sight of children.
- Store in a cool, dry place, away from direct heat and light.
Important information about all medicines
Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.
If you are having an operation or dental treatment, tell the person carrying out the treatment which medicines you are taking.
This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.
Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.
If you have any questions about this medicine ask your pharmacist.
Medically reviewed by Sanjai Sinha, MD Last updated on Jan 14, 2019.
- Side Effects
What is tetracycline?
Tetracycline is an antibiotic that fights infection caused by bacteria.
Tetracycline is used to treat many different bacterial infections of the skin, intestines, respiratory tract, urinary tract, genitals, lymph nodes, and other body systems. It is often used in treating severe acne, or sexually transmitted diseases such as syphilis, gonorrhea, or chlamydia.
Tetracycline is also used to treat infections you can get from direct contact with infected animals or contaminated food.
In some cases, tetracycline is used when penicillin or another antibiotic cannot be used to treat serious infections such as Anthrax, Listeria, Clostridium, Actinomyces, and others.
Children younger than 8 years old should not take this medicine.
Using tetracycline during pregnancy could harm the unborn baby or cause permanent tooth discoloration later in the baby’s life.
Throw away any unused tetracycline when it expires or when it is no longer needed. Do not take this medicine after the expiration date on the label has passed. Expired tetracycline can cause a dangerous syndrome resulting in damage to the kidneys.
Tetracycline passes into breast milk and may affect bone and tooth development in a nursing baby. Do not take this medication without telling your doctor if you are breast-feeding a baby.
Avoid exposure to sunlight or artificial UV rays (sunlamps or tanning beds). Tetracycline can make your skin more sensitive to sunlight and sunburn may result. Use a sunscreen (minimum SPF 15) and wear protective clothing if you must be out in the sun.
Before taking this medicine
You should not use this medicine if you are allergic to tetracycline or similar medicines such as demeclocycline, doxycycline, minocycline, or tigecycline.
To make sure tetracycline is safe for you, tell your doctor if you have:
liver disease; or
If you are using tetracycline to treat gonorrhea, your doctor may test you to make sure you do not also have syphilis, another sexually transmitted disease.
Taking this medicine during pregnancy may affect tooth and bone development in the unborn baby. Taking tetracycline during the last half of pregnancy can cause permanent tooth discoloration later in the baby’s life. Tell your doctor if you are pregnant or if you become pregnant while using this medicine.
Tetracycline can make birth control pills less effective. Ask your doctor about using a non-hormonal birth control (condom, diaphragm with spermicide) to prevent pregnancy.
Tetracycline can pass into breast milk and may affect bone and tooth development in a nursing infant. Do not breast-feed while you are taking tetracycline.
Children younger than 8 years old should not take tetracycline. Tetracycline can cause permanent tooth discoloration and can also affect a child’s growth.
How should I take tetracycline?
Take tetracycline exactly as it was prescribed for you. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.
Take tetracycline on an empty stomach, at least 1 hour before or 2 hours after a meal.
Do not take this medicine with milk or other dairy products, unless your doctor has told you to. Dairy products can make it harder for your body to absorb the medicine.
Shake the oral suspension (liquid) well just before you measure a dose. Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.
If you need surgery, tell the surgeon ahead of time that you are using tetracycline.
If you use this medicine long-term, you may need frequent medical tests.
Use this medicine for the full prescribed length of time. Your symptoms may improve before the infection is completely cleared. Skipping doses may also increase your risk of further infection that is resistant to antibiotics. Tetracycline will not treat a viral infection such as the flu or a common cold.
Do not share this medicine with another person, even if they have the same symptoms you have.
Store this medication at room temperature away from moisture and heat.
Throw away any unused tetracycline after the expiration date on the label has passed. Taking expired tetracycline can cause damage to your kidneys.
What happens if I miss a dose?
Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
What should I avoid while taking tetracycline?
For at least 2 hours before or 2 hours after taking tetracycline: avoid taking iron supplements, multivitamins, calcium supplements, antacids, or laxatives.
Antibiotic medicines can cause diarrhea, which may be a sign of a new infection. If you have diarrhea that is watery or bloody, call your doctor. Do not use anti-diarrhea medicine unless your doctor tells you to.
Avoid exposure to sunlight or tanning beds. Tetracycline can make you sunburn more easily. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.
Tetracycline side effects
Get emergency medical help if you have signs of an allergic reaction to tetracycline: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have:
severe blistering, peeling, and red skin rash;
fever, chills, body aches, flu symptoms;
pale or yellowed skin, easy bruising or bleeding;
any signs of a new infection.
Common tetracycline side effects may include:
nausea, vomiting, diarrhea, upset stomach, loss of appetite;
white patches or sores inside your mouth or on your lips;
swollen tongue, black or “hairy” tongue, trouble swallowing;
sores or swelling in your rectal or genital area; or
vaginal itching or discharge.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
What other drugs will affect tetracycline?
Tell your doctor about all your current medicines and any you start or stop using, especially:
This list is not complete. Other drugs may interact with tetracycline, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.
Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use tetracycline only for the indication prescribed.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Copyright 1996-2020 Cerner Multum, Inc. Version: 8.01.
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What is tetracycline used for?
Tetracycline is an antibiotic that is most often prescribed to treat acne (spots) and rosacea.
It’s also used to treat certain bacterial infections, for example chest infections such as bronchitis, pneumonia and mycoplasma infections, mouth infections and some sexually-transmitted infections. Additionally, it is used to treat infections transmitted by ticks, lice, fleas and mites, such as Rocky Mountain spotted fever, typhus group, Q fever and Coxiella endocarditis and tick fevers.
💡Key facts about tetracycline
- Tetracycline is only available on prescription.
- Tetracycline comes as 250mg tablets that should be taken on an empty stomach.
- Tetracycline is taken twice a day to treat acne or rosacea and four times a day to treat infections. Always complete the course prescribed by your doctor.
- Tetracycline shouldn’t be taken by children under 12 years, or by women who are pregnant or breastfeeding.
- The most common side effects are stomach ache, diarrhoea, feeling or being sick and loss of appetite.
- Don’t use sunbeds or sunlamps while you’re taking tetracycline. It’s a good idea to protect your skin with clothing or a sun cream if you’re in strong sunlight.
- It’s generally OK to drink alcohol in moderation while taking tetracycline. See below.
How does tetracycline work?
Tetracycline is a tetracycline-type antibiotic. It works by interfering with the ability of bacteria to produce proteins that are essential to them. Without these proteins the bacteria cannot grow, multiply and increase in numbers. Tetracycline therefore stops the spread of the infection and the remaining bacteria are killed by the immune system or eventually die.
Tetracycline is mainly used to treat acne because it’s active against the bacteria associated with acne, Propionebacterium acnes. This is a common type of bacteria that feeds on sebum produced by the sebaceous glands in the skin. It produces waste products and fatty acids that irritate the sebaceous glands, making them inflamed and causing spots. By controlling bacterial numbers, tetracycline brings the inflammation of the sebaceous glands under control and allows the skin to heal.
To make sure the bacteria causing an infection are susceptible to tetracycline your doctor may take a tissue sample, for example a swab from the infected area, or a urine, sputum or blood sample.
Who shouldn’t take tetracycline?
Tetracycline is not suitable for:
- Children under 12 years of age.
- Women who are pregnant. Tetracycline can be deposited in the baby’s growing bone, affecting the development of the skeleton, and in teeth, causing staining.
- Women who are breastfeeding. Tetracycline may pass into breast milk, which may cause staining of a nursing infant’s teeth (even if they have not yet erupted).
- People with decreased kidney function or kidney failure.
- People who are allergic to any ingredient of the tablets. Check the ingredients listed in the leaflet that comes with your medicine if you know you have specific allergies.
- People who are allergic to other tetracycline-type antibiotics. Make sure your doctor knows if you’ve ever had an allergic reaction to an antibiotic.
Some people might need a lower tetracycline dose or extra monitoring. Make sure your doctor knows if you have:
- Liver problems, or if you’re taking medicines that can have side effects on the liver.
- A condition called myasthenia gravis, which involves abnormal muscle weakness.
- An inflammatory condition called systemic lupus erythematosus.
Dosage: How do I take tetracycline and how often?
Tetracycline tablets should be taken on an empty stomach. This means an hour before food or two hours after food. Do not take the tablets at the same time as food, milk or dairy products, as these can stop the medicine being absorbed into the body properly and make it less effective.
Swallow the tablets whole with plenty of water while you are sitting or standing to avoid the medicine irritating the throat. Avoid taking a dose just before going to bed.
Don’t take indigestion remedies or medicines containing aluminium, calcium, iron, magnesium or zinc in the two hours before or after taking tetracycline tablets. These can reduce the absorption of tetracycline from the gut and make it less effective.
If you forget to take a tetracycline dose, take it as soon as you remember, unless it’s nearly time for your next dose. In this case just leave out the missed dose and take your next dose as usual. Do not take a double dose to make up for a missed dose.
Dosage and length of treatment varies depending on what you’re taking it for:
To treat acne and rosacea:
A typical dose is 500mg (two tablets) taken twice a day, morning and evening. For rosacea you’ll need to take it for 6 to 12 weeks. For acne you’ll need to continue treatment for at least three months. Follow the instructions given by your doctor.
To treat infections:
One or two tablets are taken four times a day. Take your doses spaced evenly throughout the day, ideally every six hours. Dosage and length of treatment depends on the type and severity of your infection. Always follow your doctor’s instructions, which will be printed on the dispensing label that your pharmacist has put on the packet of medicine.
Finish the prescribed course of tetracycline even if you feel better or it seems the infection has cleared up. Stopping the course early increases the chance that the infection will return and that the bacteria will grow resistant to the antibiotic.
Can I drink alcohol while taking tetracycline?
There is no ‘do not drink alcohol’ warning that applies to taking tetracycline because it doesn’t specifically affect the medicine itself.
However, just be aware that if you feel unwell with an infection or find tetracycline gives you a headache or upset stomach then this might be made worse by drinking alcohol. It’s also possible that drinking excessive amounts of alcohol with tetracycline could increase the risk of getting side effects on your liver.
What are the side effects of tetracycline?
Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with tetracycline. Just because a side effect is stated here doesn’t mean that all people taking this antibiotic will experience that or any side effect.
Common side effects
- Feeling or being sick.
- Stomach ache. If you find this medicine upsets your stomach it’s OK to take it with food.
- Loss of appetite.
- Difficulty or pain when swallowing (dysphagia).
Other possible side effects
- Visual disturbances.
- Overgrowth of the yeast Candida, which may cause infections such as thrush. Ask your doctor or pharmacist for advice if you think you’ve developed thrush, or any other new infection, while taking tetracycline.
- Skin reactions, such as a rash, itching or increased sensitivity of your skin to sunlight or UV light. Tell your doctor if you get a rash.
- Inflammation of the bowel (colitis). Tell your doctor if you get diarrhoea that is severe or persistent, or contains blood or mucus.
- Inflammation of the pancreas (pancreatitis). Tell your doctor if you get severe upper abdominal pain.
- Raised pressure inside the skull. Tell your doctor if you get a severe persistent headache, or double or blurred vision.
- Liver problems. Tell your doctor if you experience yellow skin or eyes (jaundice).
- Problems with your blood cells. Tell your doctor if you experience unexplained bruising, sore throat, fever or infections.
If you take tetracycline for long periods of time your doctor may want to see you regularly to monitor for any possible side effects of the medicine.
Read the leaflet that comes with the medicine or talk to your doctor or pharmacist if you want any more information about the possible side effects of tetracycline. If you think you have experienced a side effect, did you know you can report this using the yellow card website?
Can I take other medicines with tetracycline?
Before you take tetracycline, tell your doctor or pharmacist if you’re already taking any medicines, including those bought without a prescription and herbal medicines. Similarly, always check with your doctor or pharmacist before taking any new medicines while you’re taking tetracycline.
If you need to take a painkiller while you’re taking tetracycline it’s fine to take paracetamol or ibuprofen.
Tetracycline doesn’t affect hormonal contraceptives such as the pill. However, if you experience vomiting or diarrhoea while taking this antibiotic, this can potentially make your pill less effective at preventing pregnancy. If this happens to you, follow the instructions for vomiting and diarrhoea described in the leaflet provided with your pills.
Tetracycline may increase the anti-blood-clotting effects of coumarin anticoagulant medicines such as warfarin. If you’re taking warfarin your doctor may want to check your blood clotting time (INR) after you start and finish treatment with tetracycline.
Medicines to avoid
Don’t take medicines containing any of the following ingredients in the two hours before or after taking your tetracycline dose. They may reduce the absorption of tetracycline from the gut and make it less effective:
- aluminium salts
- antacids for heartburn and indigestion containing aluminium, bismuth, calcium or magnesium
- calcium supplements
- iron preparations, eg ferrous sulfate, ferrous fumarate
- magnesium salts
- quinapril tablets that contain magnesium carbonate, eg Accupro brand
- ranitidine bismuth citrate
- tripotassium dicitrato-bismuthate
- zinc salts
- Videx chewable/dispersible tablets (didanosine).
Retinoid medicines such as acitretin, alitretinoin, isotretinoin or tretinoin shouldn’t be taken with tetracycline. The combination may increase the risk of developing raised pressure within the skull (benign intracranial hypertension).
Vivotif, the oral typhoid vaccine, should not be taken until at least three days after you have finished a course of tetracycline. The antibiotic could make this vaccine less effective.
Tetracycline may decrease the blood level of atovaquone (found in the antimalarial medicine Malarone) and could make this medicine less effective.
Last updated 10.05.2018
Helen Marshall, BPharm, MRPharmS Helen Marshall, BPharm, MRPharmS A UK registered pharmacist with a background in hospital pharmacy.
Dosage Forms & Strengths
Chronic Bronchitis, Acute Exacerbation
Usual daily dose: 500 mg PO q12hr or 250 mg PO q6hr (ie, 1000 mg/day)
Higher doses (eg, 500 mg PO q6hr) may be required for severe infections or for those infections which do not respond to the smaller doses
Moderate-to- Severe Acne
Recommended initial dosage: 1 g/day PO in divided doses (based on the judgement of the clinician)
When improvement is noted, gradually reduce dose to maintenance levels ranging from 125-500 mg/day
Some patients may be able to maintain adequate remission of lesions with alternate day or intermittent therapy
Duration of long-term treatment which can safely be recommended has not been established
500 mg PO q6hr for 3 weeks accompanied by streptomycin, 1 g IM BID for the first week, THEN qDay the second week
Patients allergic to penicillin
- Early syphilis (duration
- Syphilis (duration >1 year ): 500 mg PO q6hr for 30 days
Recommended dose: 500 mg PO q6hr for 7 days
Uncomplicated urethral, endocervical or rectal infections
Infections in adults caused by Chlamydia trachomatis
500 mg PO q6hr for at least seven days
Upper respiratory tract infections caused by Streptococcus pyogenes, Streptococcus pneumoniae and Haemophilus influenzae; tetracycline should not be used for streptococcal disease unless the organism has been demonstrated to be susceptible
Lower respiratory tract infections caused by Streptococcus pyogenes, Streptococcus pneumoniae, Mycoplasma pneumoniae (Eaton agent, and Klebsiella spp)
Skin and soft tissue infections caused by Streptococcus pyogenes, Staphylococcus aureus; tetracyclines are not the drugs of choice in the treatment of any type of staphylococcal infections
Infections caused by rickettsia including Rocky Mountain spotted fever, typhus group infections, Q fever, rickettsialpox
Psittacosis caused by Chlamydophila psittaci
Infections caused by Chlamydia trachomatis (eg, uncomplicated urethral, endocervical or rectal infections, inclusion conjunctivitis, trachoma, and lymphogranuloma venereum)
Granuloma inguinale caused by Klebsiella granulomatis Relapsing fever caused by Borrelia spp Bartonellosis caused by Bartonella bacilliformis
Chancroid caused by haemophilus ducreyi
Tularemia caused by Francisella tularensis
Plaque caused by Yersinia pestis
Cholera caused by Vibrio cholerae
Brucellosis caused by Brucella species (tetracycline may be used in conjunction with an aminoglycoside)
Infections due to Campylobacter fetus
As adjunctive therapy in intestinal amebiasis caused by Entamoeba histolytica
Urinary tract infections caused by susceptible strains (eg, Escherichia coli, Klebsiella)
Other infections caused by susceptible gram-negative organisms such as E coli, Enterobacter aerogenes, Shigella spp, Acinetobacter spp, Klebsiella spp, and Bacteroides spp
In severe acne, adjunctive therapy with tetracycline may be useful
Other Infections (Penicillin-Resistant)
Syphilis and yaws caused by Treponema pallidum and pertenue, respectively
Vincent’s infection caused by Fusobacterium fusiforme
Infections caused by Neisseria gonorrhoeae
Anthrax caused by Bacillus anthracis Infections due to Listeria monocytogenes
Actinomycosis caused by Actinomyces spp
Infections due to Clostridium spp
- Total dosage should be decreased by reduction of recommended individual doses and/or by extending time intervals between doses
Also see Administration
In the treatment of streptococcal infections, administered for at least 10 days
As with other antibacterials, use of this drug may result in overgrowth of nonsusceptible organisms, including fungi
If superinfection occurs, discontinue antibacterial and institute appropriate therapy
Treat all infections due to Group A beta-hemolytic streptococci for at least 10 days
Perform incision and drainage or other surgical procedures in conjunction with antibacterial therapy, when indicated
Prescribing tetracycline in the absence of proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria
- Acinetobacter spp, Actinomyces israelii, Afipia felis, Bacillus anthracis, Bacteroides spp, Bartonella bacilliformis, Bartonella quintana, Bordetella pertussis, Borrelia recurrentis, Brucella spp, Capnocytophaga canimorsus, Campylobacter jejuni, Chlamydia spp, Citrobacter spp, Coxiella burnetii, Eikenella corrodens, Escherichia coli, Francisella tularensis, Leptospira interrogans, Helicobacter pylori, Klebsiella spp, Listeria monocytogenes, Moraxella catarrhalis, Mycoplasma pneumoniae, Neisseria gonorrhoeae, Propionibacterium acnes, Rickettsiae, Shigella spp, Staphylococcus aureus, Streptococcus pneumoniae, Treponema pallidum, Ureaplasma urealyticum, Vibrio cholerae, Yersinia pestis, Yersinia enterocolitica, Yersinia pseudotuberculosis