amantadine hydrochloride

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Related to amantadine hydrochloride: Symmetrel

amantadine hydrochloride

Dom-Amantadine (CA), Gen-Amantadine (CA), Lysovir (UK), PMS-Amantadine (CA)

Pharmacologic class: Anticholinergic-like agent

Therapeutic class: Antiviral, anti-parkinsonian

Pregnancy risk category C


Antiviral action unclear; may prevent penetration of influenza A virus into host cell. Antiparkinsonian action unknown; may ease parkinsonian symptoms by increasing dopamine release, preventing dopamine reuptake into presynaptic neurons, stimulating dopamine receptors, or enhancing dopamine sensitivity.


Capsules (liquid-filled): 100 mg

Syrup: 50 mg/5 ml

Tablets: 100 mg

Indications and dosages

Symptomatic treatment or prophylaxis of influenza type A virus in patients with respiratory conditions

Adults older than age 65 with normal renal function: 100 mg P.O. once daily

Adults to age 64 with normal renal function: 200 mg (tablets) or 4 tsp of syrup P.O. daily in a single dose, or 100 mg tablet or 2 tsp of syrup P.O. b.i.d.

Children ages 9 to 12: 100 mg P.O. q 12 hours

Children ages 1 to 9 or weighing less than 45 kg (99 lb): 4.4 to 8.8 mg/kg/day of syrup P.O. q 12 hours, not to exceed 150 mg daily

Parkinson's disease

Adults: Initially, 100 mg P.O. daily, increased to 100 mg b.i.d. if needed. If patient doesn't respond adequately, give 200 mg b.i.d., up to 400 mg/day.

Drug-induced extrapyramidal reactions

Adults: 100 mg P.O. b.i.d.; may increase dosage to maximum of 300 mg daily in divided doses

Dosage adjustment

• Renal impairment


• Hypersensitivity to drug


Use cautiously in:

• cardiac disease, hepatic disease, renal impairment, seizure disorder, psychiatric problems

• untreated closed-angle glaucoma (use not recommended)

• elderly patients

• pregnant or breastfeeding patients.


• For antiviral use, start therapy within 24 to 48 hours of symptom onset and continue for 24 to 48 hours after symptoms resolve.

• When giving as prophylactic antiviral, start therapy as soon as possible and continue for at least 10 days after exposure to virus.

• When giving with influenza vaccine, continue drug for 2 to 3 weeks while patient develops antibody response to vaccine.

Adverse reactions

CNS: depression, dizziness, drowsiness, insomnia, light-headedness, anxiety, irritability, hallucinations, confusion, ataxia, headache, nervousness, abnormal dreams, agitation, fatigue, delusions, aggressive behavior, manic reaction, psychosis, slurred speech, euphoria, abnormal thinking, amnesia, increased or decreased motor activity, paresthesia, tremor, abnormal gait, delirium, stupor, coma

CV: orthostatic hypotension, tachycardia, peripheral edema, heart failure, cardiac arrest, arrhythmias

EENT: blurred vision, mydriasis, keratitis, photosensitivity, optic nerve palsy, nasal congestion

GI: nausea, vomiting, diarrhea, constipation, dry mouth, dysphagia, anorexia

GU: urine retention, decreased libido Hematologic: leukocytosis

Musculoskeletal: involuntary muscle contractions

Respiratory: tachypnea, acute respiratory failure, pulmonary edema

Skin: purplish skin discoloration, rash, pruritus, diaphoresis

Other: edema, fever, allergic reactions including anaphylaxis


Drug-drug. Anticholinergics, antihistamines, phenothiazines, quinidine, tricyclic antidepressants: increased atropine-like adverse effects

CNS stimulants: increased CNS stimulation

Hydrochlorothiazide, triamterene: increased amantadine effects

Drug-diagnostic tests. Alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, bilirubin, blood urea nitrogen, creatine kinase, creatinine, gamma-glutamyltransferase, lactate dehydrogenase: increased levels

Drug-herbs. Angel's trumpet, jimson-weed, scopolia: increased cardiac and anticholinergic-like effects

Drug-behaviors. Alcohol use: increased CNS adverse reactions

Patient monitoring

Monitor patient for depression and suicidal ideation.

• Watch for mental status changes, especially in elderly patients.

• Stay alert for worsening of psychiatric problems if patient has a history of such problems or substance abuse.

• Monitor for orthostatic hypotension.

• Evaluate for signs and symptoms of fluid overload.

• Monitor kidney and liver function test results.

Patient teaching

Caution patient that taking more than prescribed dosage may lead to serious adverse reactions or even death.

• Advise patient to establish effective bedtime routine and to take drug several hours before bedtime to minimize insomnia.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.

• Advise patient to minimize GI upset by eating small, frequent servings of foods and drinking plenty of fluids.

• Instruct patient to contact prescriber if he develops signs or symptoms of depression.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, herbs, and behaviors mentioned above.

McGraw-Hill Nurse's Drug Handbook, 7th Ed. Copyright © 2013 by The McGraw-Hill Companies, Inc. All rights reserved

a·man·ta·dine hy·dro·chlor·ide

(ă-man'tă-dēn hī'drō-klōr'īd),
An antiviral agent used to treat influenza; also used to treat parkinsonism, in which it increases dopamine release and reduces its reuptake into dopaminergic nerve terminals of substantia nigra neurons.
Farlex Partner Medical Dictionary © Farlex 2012

a·man·ta·dine hy·dro·chlor·ide

(ă-mantă-dēn hīdrŏ-klōrīd)
An antiviral agent used to treat influenza; also used to treat parkinsonism.
Medical Dictionary for the Dental Professions © Farlex 2012
References in periodicals archive ?
The company said Amantadine Hydrochloride Capsules USP, 100 mg is the therapeutic equivalent to the reference standard drug, Amantadine Hydrochloride Capsules USP, 100 mg, of Sandoz Pharmaceuticals.
Double-blind study designed to assess the prophylactic efficacy of an analogue of amantadine hydrochloride. J.
Clinical trials have documented that amantadine hydrochloride [4,5,6,8,13] and its analog rimantadine hydrochloride [3,5,10,13,12] are effective drugs for the prophylaxis and treatment of influenza A virus infection.
He was treated with amantadine hydrochloride and a combination of levodopa and carbidopa.
On the evening of December 1, 293 of the 299 residents in the facility each received 100 mg of amantadine hydrochloride as treatment for the eight ill residents and as prophylaxis against influenza A infection for the other 285 residents.
Although the vaccine and circulating influenza virus strains appear to be wellmatched, the antiviral drug amantadine hydrochloride should be considered as an adjunct to vaccination for prevention and treatment of influenza A infection.
Surveillance for the 1991-92 influenza season indicates that the dominant circulating viruses are influenza A [1], for which amantadine hydrochloride is effective for prevention and treatment [2].