What does amantadine do?

Symmetrel

SIDE EFFECTS

The adverse reactions reported most frequently at the recommended dose of SYMMETREL (amantadine hydrochloride) (5-10%) are: nausea, dizziness (lightheadedness), and insomnia.

Less frequently (1-5%) reported adverse reactions are: depression, anxiety and irritability, hallucinations, confusion, anorexia, dry mouth, constipation, ataxia, livedo reticularis, peripheral edema, orthostatic hypotension, headache, somnolence, nervousness, dream abnormality, agitation, dry nose, diarrhea and fatigue.

Infrequently (0.1-1%) occurring adverse reactions are: congestive heart failure, psychosis, urinary retention, dyspnea, skin rash, vomiting, weakness, slurred speech, euphoria, thinking abnormality, amnesia, hyperkinesia, hypertension, decreased libido, and visual disturbance, including punctate subepithelial or other corneal opacity, corneal edema, decreased visual acuity, sensitivity to light, and optic nerve palsy.

Rare (less than 0.1%) occurring adverse reactions are: instances of convulsion, leukopenia, neutropenia, eczematoid dermatitis, oculogyric episodes, suicidal attempt, suicide, and suicidal ideation (see WARNINGS).

Other adverse reactions reported during postmarketing experience with SYMMETREL (amantadine hydrochloride) usage include:

Nervous System/Psychiatric

coma, stupor, delirium, hypokinesia, hypertonia, delusions, aggressive behavior, paranoid reaction, manic reaction, involuntary muscle contractions, gait abnormalities, paresthesia, EEG changes, and tremor. Abrupt discontinuation may also precipitate delirium, agitation, delusions, hallucinations, paranoid reaction, stupor, anxiety, depression and slurred speech;

Cardiovascular

cardiac arrest, arrhythmias including malignant arrhythmias, hypotension, and tachycardia;

Respiratory

acute respiratory failure, pulmonary edema, and tachypnea;

Gastrointestinal

dysphagia;

Hematologic

leukocytosis; agranulocytosis

Special Senses

keratitis and mydriasis;

Skin and Appendages

pruritus and diaphoresis;

Miscellaneous

neuroleptic malignant syndrome (see WARNINGS), allergic reactions including anaphylactic reactions, edema, fever, pathological gambling, increased libido including hypersexuality, and impulse control symptoms.

Laboratory Test

elevated: CPK, BUN, serum creatinine, alkaline phosphatase, LDH, bilirubin, GGT, SGOT, and SGPT.

Read the entire FDA prescribing information for Symmetrel (Amantadine Hydrochloride)

Amantadine Hcl Capsule, Extended Release 24 Hr (Capsule, ER Hr)

Side Effects

Blurred vision, nausea, loss of appetite, drowsiness, dizziness, lightheadedness, headache, dry mouth, constipation, or trouble sleeping may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Dizziness and lightheadedness can increase the risk of falling. Get up slowly when rising from a sitting or lying position.

To relieve dry mouth, suck (sugarless) hard candy or ice chips, chew (sugarless) gum, drink water, or use a saliva substitute.

If you are taking the extended-release tablets, an empty tablet shell may appear in your stool. This effect is harmless because your body has already absorbed the medication.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including: purplish-red blotchy spots on the skin (especially on the legs), swelling of the ankles/feet, difficulty urinating, vision changes, unusual strong urges (such as increased gambling, increased sexual urges, uncontrolled spending), mental/mood changes (such as anxiety, depression, hallucinations, suicidal thoughts/attempts), muscle spasms.

Get medical help right away if you have any very serious side effects, including: seizure.

Some people taking amantadine have fallen asleep suddenly during their usual daily activities (such as talking, driving). You might fall asleep without warning or without feeling drowsy. This effect can happen at any time even if you have used this medication for a long time. If you have increased sleepiness or fall asleep suddenly during the day, tell your doctor right away. Your risk is higher if you drink alcohol or take other medications that can make you drowsy. Do not drive or do other activities for which you need to be alert (see also Precautions section).

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US –

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada – Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

amantadine (Gocovri, Osmolex ER, Symmetrel)

Brand Names: Gocovri, Osmolex ER, Symmetrel

Generic Name: amantadine

  • What is amantadine (Gocovri, Osmolex ER, Symmetrel)?
  • What are the possible side effects of amantadine (Gocovri, Osmolex ER, Symmetrel)?
  • What is the most important information I should know about amantadine (Gocovri, Osmolex ER, Symmetrel)?
  • What should I discuss with my healthcare provider before taking amantadine (Gocovri, Osmolex ER, Symmetrel)?
  • How should I take amantadine (Gocovri, Osmolex ER, Symmetrel)?
  • What happens if I miss a dose (Gocovri, Osmolex ER, Symmetrel)?
  • What happens if I overdose (Gocovri, Osmolex ER, Symmetrel)?
  • What should I avoid while taking amantadine (Gocovri, Osmolex ER, Symmetrel)?
  • What other drugs will affect amantadine (Gocovri, Osmolex ER, Symmetrel)?
  • Where can I get more information (Gocovri, Osmolex ER, Symmetrel)?

What is amantadine (Gocovri, Osmolex ER, Symmetrel)?

Amantadine is an antiviral medicine that blocks the actions of viruses in your body.

Amantadine is used to treat or prevent influenza A in adults and children. Amantadine may not be effective during every flu season because certain strains of the virus may be resistant to this medicine. Amantadine should not be used in place of getting a yearly flu shot. The Centers for Disease Control recommends an annual flu shot to help protect you each year from new strains of influenza virus.

Amantadine is also used to treat Parkinson’s disease and “Parkinson-like” symptoms such as stiffness or tremors, shaking, and repetitive uncontrolled muscle movements that may be caused by the use of certain drugs.

Amantadine may also be used for purposes not listed in this medication guide.

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capsule, red, imprinted with GG 634, GG 634

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capsule, yellow, imprinted with C-122

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capsule, red, imprinted with GG 634, GG 634

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capsule, yellow, imprinted with A1

Amantadine 100 mg 005914930

capsule, white, imprinted with A973

Amantadine 100 mg 623320246

capsule, red, imprinted with A226

Amantadine 100 mg-APH

capsule, red, imprinted with INV 211, INV 211

Amantadine 100 mg-GG

capsule, red, imprinted with GG 634, GG 634

Amantadine 100 mg-UDL

capsule, yellow, imprinted with C-122

Amantadine 100 mg-UPS

capsule, yellow, imprinted with C-122

Amantadine HCl 100 mg 009046630

capsule, red, imprinted with 652

What are the possible side effects of amantadine (Gocovri, Osmolex ER, Symmetrel)?

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • extreme drowsiness, falling asleep suddenly even after feeling alert;
  • a light-headed feeling, like you might pass out;
  • shortness of breath (even with mild exertion), swelling in your hands or feet;
  • painful or difficult urination;
  • depression, agitation, aggression, behavior changes, hallucinations, thoughts of hurting yourself;
  • a seizure; or
  • severe nervous system reaction–very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors.

You may have increased sexual urges, unusual urges to gamble, or other intense urges while taking this medicine. Talk with your doctor if this occurs.

Side effects may be more likely in older adults.

Common side effects may include:

  • dizziness, falls;
  • dry mouth;
  • swelling in your legs or feet;
  • nausea, constipation; or
  • sleep problems (insomnia).

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 is the most important information I should know about amantadine (Gocovri, Osmolex ER, Symmetrel)?

You should not use amantadine if you received a nasal flu vaccine in the past 14 days.

Do not receive a nasal flu vaccine while taking amantadine, and for at least 48 hours after your last dose.

Amantadine is a treatment for Parkinson’s disease that can also be used to treat fatigue in patients with multiple sclerosis (MS). Many generic formulations of amantadine are available. An extended release formulation (ADS-5102/Gocovri) is currently being developed by Adamas Pharmaceuticals.

How amantadine works

MS is a disease caused by the immune system mistakenly attacking the myelin sheath or the fatty coating that protects nerve fibers, and increases the speed of electrical signals that travel along them. The attacks cause damage to the nerve fibers, leading to neurodegeneration, which is responsible for the symptoms of MS.

Fatigue is a common MS symptom, occurring in more than 80 percent of cases. Fatigue management plans can help patients learn how to make behavioral changes and develop strategies to improve their lives. Therapies such as amantadine can also aid in combating fatigue.

How amantadine reduces fatigue in MS patients is not fully understood but it is thought that the treatment acts on the brain by increasing the release of a neurotransmitter or cell-signaling molecule called dopamine, and boosting the brain’s response to another neurotransmitter called norepinephrine.

Both dopamine and norepinephrine control how sensitive the brain is to nerve signals. Therefore, it’s possible that the combination of more dopamine and a stronger response to norepinephrine is responsible for the decrease in fatigue that’s experienced by some MS patients who use amantadine.

Amantadine may also act on the glutamate receptors of the brain, which are sometimes called the glutamate N-methyl-D-aspartate or NMDA receptors. Overactive NMDA receptors may contribute to some of the symptoms of MS, and research has focused on the potential therapeutic effect of reducing the activity of these receptors. Amantadine may bind to NMDA receptors and reduce their activity.

Amantadine in clinical trials for MS

A Phase 2 clinical trial (NCT02471222) to study the safety and efficacy of ADS-5102 to treat MS patients with fatigue showed it was well-tolerated. Patients improved their walking speed in a timed 25-foot walking test, which measures the time it takes for patients to walk a distance of 25 feet.

A Phase 3 ongoing clinical trial (NCT03185065) is testing the effects of commonly used medications to treat fatigue in MS. It enrolled 140 participants who were randomly divided into four groups and treated with either ADS-5102, modafinil, methylphenidate, or a placebo.

A Phase 3 clinical trial (NCT03436199) is currently recruiting MS patients with fatigue for a multicenter placebo-controlled trial in states across the U.S. A total of 540 patients are expected to enroll, and will be randomly assigned to receive either a placebo, 137 mg of ADS-5102, or 274 mg of ADS-5102 once daily at bedtime for 12 weeks. Fatigue will be assessed at the beginning and end of the trial using a timed 25-foot walking test.

An open-label extension study (NCT03567057) of the above trial is also planned in Colorado, Connecticut, Georgia, New York, and Washington. Patients will receive ADS-5102 once per day at bedtime for 52 weeks. Safety and tolerability are the primary goal measures, but patients will also be asked to complete a timed 25-foot walking test at four, 12, 24, and 52 weeks of the study to evaluate the efficacy of treatment.

Other information

Amantadine can cause side effects such as bladder pain, blurred vision, confusion, dizziness, fainting, falls, swelling of the hands and feet, and pain in the lower back or side.

***

Multiple Sclerosis News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.

Before taking amantadine,

  • tell your doctor and pharmacist if you are allergic to amantadine, any other medications, or any of the ingredients in amantadine capsules, extended-release capsules, tablets, or liquid. Ask your pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: acetazolamide (Diamox); antihistamines; co-trimoxazole (Bactrim, Septra, Sulfatrim); dichlorphenamide (Daranide); hydrochlorothiazide with triamterene (Maxzide, Dyazide); ipratropium (Atrovent); medications for irritable bowel disease, mental illness, motion sickness, sleep, or urinary problems; other medications to treat Parkinson’s disease; methazolamide (GlaucTabs, Neptazane); quinine (Qualaquin); quinidine; sedatives; sodium bicarbonate (Alka-Seltzer, in Zegerid); stimulants; or thioridazine (Mellaril). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • tell your doctor if you have kidney disease. Your doctor may tell you not to take amantadine.
  • tell your doctor if you drink or have ever drunk large amounts of alcohol, use or have ever used street drugs, or have overused prescription medications, or if you have or have ever had epilepsy or any other type of seizures, a sleep disorder, urinary tract infections, mental illness, glaucoma (a condition in which increased pressure in the eye can lead to gradual loss of vision), eczema (atopic dermatitis; a skin disease that causes the skin to be dry and itchy and to sometimes develop red, scaly rashes), heart failure, swelling of the hands, feet, ankles, or lower legs, low blood pressure, or liver disease.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking amantadine, call your doctor immediately. Amantadine may cause harm to the fetus.
  • if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking amantadine.
  • you should know that amantadine may make you drowsy or cause blurred vision. Do not drive a car, operate machinery, or participate in potentially dangerous activities until you know how this medication affects you.
  • ask your doctor about the safe use of alcoholic beverages while you are taking amantadine. Alcohol can make the side effects from amantadine worse.
  • you should know that amantadine may cause dizziness, lightheadedness, and fainting when you get up too quickly from a lying position. This is more common when you first start taking amantadine or if your dose has been increased. To avoid this problem, get out of bed slowly, resting your feet on the floor for a few minutes before standing up.
  • do not have any vaccinations without talking to your doctor.
  • you should know that some people taking amantadine and other similar medications used to treat Parkinson’s disease, have developed gambling problems or had other intense urges or behaviors that were compulsive or unusual for them, such as increased sexual urges, binge eating, or uncontrolled spending. Call your doctor if you have an urge to gamble that is difficult to control, you have intense urges, or you are unable to control your behavior. Tell your family members about this risk so that they can call the doctor even if you do not realize that your gambling or any other intense urges or unusual behaviors have become a problem.

amantadine hydrochloride
Symmetrel

Pharmacologic classification:synthetic cyclic primary amine
Therapeutic classification:antiviral, antiparkinsonian
Pregnancy risk category C

Available forms
Available by prescription only
Capsules:100 mg
Syrup:50 mg/5 ml
Tablets:100 mg

Indications and dosages
Prophylaxis or symptomatic treatment of influenza type A virus, respiratory tract illnesses in geriatric or debilitated patients. Adults up to age 64 and children age 10 and older who weigh more than 40 kg (88 lb): 200 mg P.O. daily in a single dose or divided b.i.d.
Children ages 1 to 9: 4.4 to 8.8 mg/kg P.O. daily up to a maximum of 150 mg daily. To reduce toxicity, 5 mg/kg daily given in one or two divided doses (up to a maximum of 150 mg daily) is recommended.
Adults older than age 64: 100 mg P.O. once daily. Continue treatment for 24 to 48 hours after symptoms disappear. Prophylaxis should start as soon as possible after initial exposure and continue for at least 10 days after exposure. Prophylactic treatment may be continued up to 90 days for repeated or suspected exposures if influenza virus vaccine is unavailable. If used with influenza virus vaccine, continue dose for 2 to 4 weeks until protection from vaccine develops.
Drug-induced extrapyramidal reactions. Adults: 100 to 300 mg P.O. daily in divided doses.
Idiopathic parkinsonism, parkinsonian syndrome. Adults: 100 mg P.O. b.i.d.; in patients who are seriously ill or receiving other antiparkinsonian drugs, 100 mg daily for at least 1 week; then 100 mg b.i.d., p.r.n. Patient may benefit from as much as 400 mg daily, but doses over 200 mg must be closely supervised.
≡ Dosage adjustment. For patients with renal dysfunction, base maintenance dosage on creatinine clearance value, as follows. For syrup, give 200 mg P.O. on the first day. For capsules, give 200 mg P.O the first day, and then 100 mg daily if creatinine clearance is between 30 and 50 ml/minute. Give 200 mg on the first day and 100 mg q alternating day if it’s 15 to 29 ml/minute. Give 200 mg q 7 days if it’s below 15 ml/minute. Patients undergoing long-term hemodialysis should receive 200 mg P.O. q 7 days.

Pharmacodynamics
Antiviral action: Amantadine interferes with viral uncoating of the RNA in lysosomes. In vitro, amantadine is active only against influenza type A virus. (However, spontaneous resistance commonly occurs.) In vivo, amantadine may protect against influenza type A virus in 70% to 90% of patients; when administered within 24 to 48 hours of onset of illness, it reduces duration of fever and other systemic symptoms.
Antiparkinsonian action: Amantadine is thought to cause the release of dopamine in the substantia nigra.

Pharmacokinetics
Absorption: Well absorbed from the GI tract with oral administration. Usual serum level is 0.2 to 0.9 mcg/ml. (Neurotoxicity may occur at levels exceeding 1.5 mcg/ml.)
Distribution: Distributed widely throughout body; crosses the blood-brain barrier.
Metabolism: About 10% of dose is metabolized.
Excretion: About 90% of dose is excreted unchanged in urine, primarily by tubular secretion. Portion of drug may appear in breast milk. Excretion rate depends on urine pH (acidic pH enhances excretion). Elimination half-life in patients with normal renal function is about 24 hours; in those with renal dysfunction, it may be prolonged to 10 days.

Route Onset Peak Duration
P.O. Unknown 1-4 hr Unknown

Contraindications and precautions
Contraindicated in patients hypersensitive to drug. Don’t use in patients with untreated angle-closure glaucoma. Use cautiously in elderly patients and in patients with seizure disorders, heart failure, peripheral edema, hepatic disease, mental illness, eczematoid rash, renal impairment, orthostatic hypotension, and CV disease.

Interactions
Drug-drug. Benztropine and trihexyphenidyl in large doses: May potentiate anticholinergic adverse effects of these drugs, possibly causing confusion and hallucinations. Reduce dosage of either drug if these effects occur.
CNS stimulants:May cause additive stimulation. Avoid use together.
Co-trimoxazole: Decreases renal clearance of amantadine with potential for toxic delirium. Avoid use together.
Hydrochlorothiazide, triamterene:May decrease urinary amantadine excretion when used together, resulting in increased serum amantadine level and possible toxicity. Avoid use together.
Drug-herb. Jimsonweed:May adversely affect CV system function. Discourage use together.
Drug-lifestyle. Alcohol use:May result in light-headedness, confusion, fainting, and hypotension. Discourage alcohol use.

Adverse reactions
CNS: depression, fatigue, confusion, dizziness, hallucinations, anxiety, irritability, ataxia, insomnia, headache, light-headedness.
CV: peripheral edema, orthostatic hypotension, heart failure.
GI: anorexia, nausea, constipation, vomiting, dry mouth.
Skin: livedo reticularis with prolonged use.

Effects on lab test results
None reported.

Overdose and treatment
Overdose may cause nausea, vomiting, anorexia, hyperexcitability, tremors, slurred speech, blurred vision, lethargy, anticholinergic symptoms, seizures, and possible ventricular arrhythmias, including torsades de pointes and ventricular fibrillation. CNS effects result from increased levels of dopamine in the brain.
Treatment includes immediate gastric lavage or emesis induction along with supportive measures, forced fluids, and, if necessary, I.V. administration of fluids. Urine acidification may be used to increase drug excretion. Physostigmine may be given (1 to 2 mg by slow I.V. infusion at 1- to 2-hour intervals) to counteract CNS toxicity. Seizures or arrhythmias may be treated with conventional therapy. Monitor patient closely.

Special considerations
• To prevent orthostatic hypotension, advise patient to move slowly when changing positions (especially when standing up).
• If patient experiences insomnia, administer dose several hours before bedtime.
• Monitor patient’s blood pressure if dizziness or light-headedness occurs.
• Prophylactic drug use is recommended for selected high-risk patients who can’t receive influenza virus vaccine. Manufacturer recommends prophylactic therapy lasting up to 90 days with possible repeated or unknown exposure.
Pregnant patients
• There are no adequate controlled studies in pregnant women. Use drug only when benefits outweigh the risks.
Breast-feeding patients
• Drug appears in breast milk. Avoid breast-feeding during therapy with amantadine.
Pediatric patients
• Safety and effectiveness of drug in children younger than age 1 haven’t been established.
Geriatric patients
• Geriatric patients are more susceptible to adverse neurologic effects; dividing daily dosage into two doses may reduce risk.

Patient education
• Warn patient that drug may impair mental alertness.
• Advise patient to take drug after meals to ensure best absorption.
• Caution patient to avoid abrupt position changes because these may cause light-headedness or dizziness.
• If drug is being taken to treat parkinsonism, warn patient not to discontinue it abruptly because doing so could precipitate a parkinsonian crisis.
• Warn patient to avoid alcohol while taking drug.
• Instruct patient to report adverse effects promptly, especially dizziness, depression, anxiety, nausea, and urine retention.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use

Amantadine is the generic form of the brand-name drug Symmetrel, which is used to treat and prevent respiratory infections caused by the influenza A virus.

It can also treat symptoms of Parkinson’s disease, such as stiffness and shaking, and conditions that are similar to Parkinson’s disease.

Amantadine was initially used to prevent influenza A during flu season. Later, doctors discovered its benefits for treating symptoms of Parkinson’s disease.

According to the Centers for Disease Control and Prevention (CDC), this medication should not be used by itself to treat or prevent influenza A because one strain of this virus in the United States and Canada is resistant to the medication.

Amantadine is an antiviral drug that is believed to work by stopping the growth of a virus. It helps treat the symptoms of Parkinson’s disease by increasing the effects of dopamine. Dopamine is a neurotransmitter in the brain; people with Parkinson’s disease typically have low levels of dopamine.

Amantadine comes in a capsule and liquid form to be taken by mouth.

Amantadine Warnings

Amantadine should not be used as a substitute for a flu vaccine and it should not be used with the flu vaccine that is inhaled through the nose because a serious interaction may occur.

This medicine may cause some people to become irritable, agitated, or display other abnormal behaviors. It may also cause suicidal thoughts or tendencies in some patients.

Before taking amantadine, tell your doctor if you have or have ever had:

  • Epilepsy or any other type of seizures
  • Heart disease
  • Heart failure
  • Kidney disease
  • Liver disease
  • Low blood pressure
  • Recurring skin rash
  • Mental illness
  • Untreated closed-angle glaucoma (a type of eye disease)

You should not take more or less of amantadine than your doctor prescribes. Don’t stop taking this drug without first talking with your doctor.

In patients with Parkinson’s disease, the effects of amantadine may not be noticed for several weeks. If this medicine causes insomnia, take your last dose several hours before bedtime.

Pregnancy and Amantadine

There are no well-controlled studies to evaluate amantadine’s safety in pregnancy, so the risks and benefits should be taken into consideration to determine if this medication should be used in pregnant women.

Amantadine is excreted into human breast milk in low concentrations. The manufacturer recommends that this drug should be used cautiously in nursing mothers.

Amantadine is a medication that is useful in treating some symptoms of Parkinson’s disease. It may cause greater amounts of dopamine to be released in the brain. Amantadine can be used by itself to treat people in the early stages of Parkinson’s disease. In the early stages of disease, it can help improve slow movements and rigidity.

It may be used in combination with other medications (Sinemet®) in later stages of Parkinson’s disease. It can help to reduce dyskinesias, involuntary movements that may result from taking some Parkinson’s medications.

Amantadine is available in 100 mg capsules and tablets. It is usually given 2 to 4 times daily.

Things to know

  1. Side effects are rare. In a few cases, patients may note difficulty falling asleep, agitation, difficulty concentrating, dry mouth, swelling of the legs, hands or feet, blurred vision, dizziness, skin mottling (changes in color). Let us or your neurologist know if these are severe or do not go away.
  2. Amantadine may cause an upset stomach, taking it with food or milk will help.
  3. Taking your last dose several hours before bedtime can help prevent insomnia.
  4. Rarely, patients experience confusion or hallucinations. This is seen more in the elderly population.
  5. Let your doctor and pharmacist know what other medications you take: especially Cogentin® (benztropine), Artane® (trihexyphenidyl), Maxzide® or Dyazide® (hydrochlorothiazide with triamterene). These medications can interact with Amantadine.

Amantadine capsules or tablets

What is this medicine?

AMANTADINE (a MAN ta deen) is an antiviral medicine. It is used to prevent and to treat a specific type of flu called influenza A. It will not work for colds, other types of flu, or other viral infections. This medicine is also used to treat Parkinson’s disease and other movement disorders.

This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

COMMON BRAND NAME(S): Symmetrel

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:

  • depression or other mental illness

  • eczema

  • glaucoma

  • heart failure

  • if you drink alcohol

  • kidney disease

  • low blood pressure

  • narcolepsy

  • seizures

  • sleep apnea

  • suicidal thoughts, plans, or attempt; a previous suicide attempt by you or a family member

  • an unusual or allergic reaction to amantadine, other medicines, foods, dyes, or preservatives

  • pregnant or trying to get pregnant

  • breast-feeding

How should I use this medicine?

Take this medicine by mouth with a full glass of water. Follow the directions on the prescription label. Take your medicine at regular intervals. Do not take your medicine more often than directed. Take all of your medicine as directed even if you think your are better. Do not skip doses or stop your medicine early. Contact your pediatrician or health care professional regarding the useof this medicine in children. While this drug may be prescribed for children as young as 1 year old for selected conditions, precautions do apply. Patients over 65 years old may have a stronger reaction and need a smaller dose.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medicine?

  • acetazolamide

  • alcohol

  • atropine

  • antihistamines for allergy, cough and cold

  • benztropine

  • bupropion

  • certain medicines for bladder problems like oxybutynin, tolterodine

  • certain medicines for stomach problems like dicyclomine, hyoscyamine

  • certain medicines for travel sickness like scopolamine

  • ipratropium

  • methazolamide

  • quinidine

  • quinine

  • sodium bicarbonate

  • some flu vaccines

  • thioridazine

  • trihexyphenidyl

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medicine?

Tell your doctor or health care professional if your symptoms do not improve.

You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells. Alcohol may interfere with the effect of this medicine. Avoid alcoholic drinks.

If you are taking this medicine for Parkinson’s disease or a movement disorder, be careful. Slowly increase your daily activities as your condition improves. Do not suddenly stop taking your medicine because you may develop a severe reaction.

You may get dry mouth or eyes, or blurry vision while taking this medicine. Try sugarless gum or hard candy, and drink 6 to 8 glasses of water daily. Brush and floss your teeth regularly and carefully to avoid teeth and gum problems. You may want to wet your eyes with lubricating eye drops. Talk to your doctor if these symptoms become a problem.

There have been reports of increased sexual urges or other strong urges such as gambling while taking some medicines for Parkinson’s disease. If you experience any of these urges while taking this medicine, you should report it to your health care provider as soon as possible.

You should check your skin often for changes to moles and new growths while taking this medicine. Call your doctor if you notice any of these changes.

What side effects may I notice from receiving this medicine?

Side effects that you should report to your doctor or health care professional as soon as possible:

  • allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue

  • anxiety

  • breathing problems

  • changes in vision

  • color changes on the skin

  • confusion

  • depressed mood

  • eye pain

  • falling asleep during normal activities like driving

  • hallucination, loss of contact with reality

  • new or increased gambling urges, sexual urges, uncontrolled spending, binge or compulsive eating, or other urges

  • seizures

  • signs and symptoms of low blood pressure like dizziness; feeling faint or lightheaded, falls; unusually weak or tired

  • swelling in your legs and feet

  • suicidal thoughts or other mood changes

  • trouble passing urine or change in the amount of urine

  • trouble sleeping

  • uncontrolled movements of the mouth, head, hands, feet, shoulders, eyelids or other unusual muscle movements

Side effects that usually do not require medical attention (report these to your doctor or health care professional if they continue or are bothersome):

  • constipation

  • dizziness

  • drowsiness

  • dry mouth

  • headache

  • nausea

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medicine?

Keep out of the reach of children.

Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Keep container tightly closed. Throw away any unused medicine after the expiration date.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.

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