amantadine

REMS

Gocovri

Treatment of the following:
- Dyskinesia in patients with Parkinson’s disease (in combination with levodopa-based therapy);
- “Off” episodes in patients with Parkinson's disease (as adjunctive treatment to levodopa/carbidopa).

Immediate-release only

Prophylaxis and treatment of influenza A infections.

Action ⬆ ⬇

Potentiates the action of dopamine in the CNS.
Prevents penetration of influenza A virus into host cell.

Therapeutic effects:

Relief of symptoms from Parkinson's disease.
Prevention and decreased symptoms of influenza A viral infection.

Pharmacokinetics ⬆ ⬇

Absorption: Well absorbed from the GI tract.

Distribution: Distributed to various body tissues and fluids. Crosses blood-brain barrier.

Metabolism/Excretion: Excreted unchanged in the urine.

Half-Life: 10–28 hr.

Time/Action Profile ⬆ ⬇

(antiparkinson effect)

ROUTE	ONSET	PEAK	DURATION
PO	within 48 hr	up to 2 wk	unknown

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
End-stage renal disease (CCr <15 mL/min) (extended-release only).

Use Cautiously in:

Seizure disorders;
Liver disease;
Psychosis;
HF;
Renal impairment (dose ↓/↑ dosing interval required if CCr ≤50 mL/min);
May ↑ susceptibility to rubella infections;
OB: Safety not established in pregnancy;
Lactation: Safety not established in breastfeeding;
Geri: Older adults may have sensitivity to adverse effects.

Adv. Reactions/Side Effects ⬆ ⬇

CV: orthostatic hypotension, HF, edema

Derm: mottling, (livedo reticularis), melanoma, rash

EENT: blurred vision, dry mouth

GI: anorexia, constipation, nausea, vomiting

GU: urinary retention

Hemat: leukopenia, neutropenia

Neuro: ataxia, dizziness, insomnia, anxiety, confusion, depression, drowsiness, psychosis, SEIZURES, SUICIDAL THOUGHTS/ATTEMPTS, urges (gambling, sexual)

Resp: dyspnea

Interactions ⬆ ⬇

Drug-drug:

Concurrent use of antihistamines, phenothiazines, quinidine, disopyramide, and tricyclic antidepressants may ↑ anticholinergic effects (dry mouth, blurred vision, constipation).
↑risk of adverse CNS reactions withalcohol.
↑risk of CNS stimulation with other CNS stimulants.

Route/Dosage ⬆ ⬇

Extended-release products are not interchangeable with immediate-release products.

Parkinson’s Disease

PO (Adults ): Immediate release: 100 mg twice daily; may ↑ to max of 400 mg/day in divided doses;Extended release: 137 mg once daily at bedtime; may ↑ after 1 wk to 274 mg once daily at bedtime.

Drug-Induced Extrapyramidal Reactions

PO (Adults ): Immediate release: 100 mg twice daily; may ↑ at weekly intervals (max dose = 300 mg/day in divided doses).

Influenza A Infection

PO (Adults and Children >12 yr): Treatment (immediate release): 200 mg/day as a single dose or 100 mg bid (not >100 mg/day in geriatric patients); Prophylaxis (immediate release): 100 mg/day in 1–2 divided doses.
PO (Children 10–12 yr): Immediate release: 100 mg every 12 hr or 5 mg/kg/day in 1–2 divided doses; not to exceed 200 mg/day.
PO (Children 1–9 yr): Immediate release: 5 mg/kg/day in 1–2 divided doses; not to exceed 150 mg/day.

Renal Impairment

PO (Adults ): CCr 30–50 mL/min: Immediate release: 200 mg on the first day; then 100 mg once daily; CCr 15–29 mL/min: Immediate release: 200 mg on the first day; then 100 mg every other day; <15 mL/min or hemodialysis patients: Immediate release: 200 mg once every 7 days.

Renal Impairment

PO (Adults ): CCr 30–59 mL/min: Extended release: 68.5 mg once daily at bedtime; may ↑ after 1 wk to 137 mg once daily at bedtime; Extended release: 129 mg every 48 hr in the morning; may ↑ every 3 wk (max dose = 322 mg every 48 hr in the morning); CCr 15–29 mL/min: Extended release: 68.5 mg once daily at bedtime (max dose = 68.5 mg/day); Extended release: 129 mg every 96 hr in the morning; may ↑ every 4 wk (max dose = 322 mg every 96 hr in the morning); <15 mL/min or hemodialysis patients: Extended release: Contraindicated.

Availability ⬆ ⬇

(Generic available)

Immediate-release tablets: 100 mg
Liquid-filled capsules: 100 mg
Extended-release capsules (Gocovri): 68.5 mg; 137 mg
Syrupraspberry flavor: 50 mg/5 mL

Assessment ⬆ ⬇

Monitor BP periodically. Assess for drug-induced orthostatic hypotension.
- Monitor vital signs periodically during first few days of dose adjustment in patients receiving >200 mg daily; side effects are more likely.
- Monitor closely for changes in behavior that could indicate the emergence or worsening of suicidal thoughts or behavior or depression.
- Assess for HF (peripheral edema, weight gain, dyspnea, rales/crackles, JVD), especially in patients on chronic therapy or with a history of HF.
- Assess skin. Monitor for appearance of a diffuse red mottling of the skin (livedo reticularis), especially in the lower extremities or on exposure to cold. Disappears with continued therapy but may not completely resolve until 2–12 wk after therapy has been discontinued. Assess for melanomas.
- Monitor for seizures, renal failure, and respiratory or CNS depression.Monitor intake and output closely in geriatric patients. May cause urinary retention. Report significant discrepancy or bladder distention.
Parkinson’s Disease: Assess akinesia, rigidity, tremors, and gait disturbances before and throughout therapy.
Influenza Prophylaxis or Treatment: Monitor respiratory status, sputum, and temperature periodically. Supportive treatment is indicated if symptoms occur.

Lab Test Considerations:

Monitor for elevations in CK, BUN, serum creatinine, alkaline phosphatase, bilirubin, and liver enzymes.

Toxicity and Overdose:

Symptoms of toxicity include CNS stimulation (confusion, mood changes, tremors, seizures), cardiac abnormalities (arrhythmia, tachycardia, HTN), respiratory distress, pulmonary edema, and renal impairment (↑ BUN and serum creatinine).

Implementation ⬆ ⬇

Do not confuse amantadine with amiodarone.
PO: Administer immediate-release tablets/capsules once daily in the morning without regard to food. DNC: Swallow whole; do not crush, break, or chew. Do not administer last dose of medication near bedtime; may produce insomnia.
- Administer extended-release capsules once daily at bedtime without regard to food. DNC: Do not crush, chew, or divide capsules. May open capsule and sprinkle contents on soft food (applesauce). Swallow immediately; do not store mixture.
- Measure liquid doses using drug-specific measuring device.
- Administering amantadine in divided doses may decrease CNS side effects.
- The contents of capsules may be mixed with food or fluids if the patient has difficulty swallowing.
Antiviral Prophylaxis: Start therapy in anticipation of contact or as soon as possible after exposure and continue for at least 10 days following exposure. Infectious period is just before onset of symptoms to up to 1 wk after. If vaccine is unavailable or contraindicated, may be administered up to 90 days to protect from repeated exposures.
- May be used with inactivated influenza A virus vaccine until protective antibody response develops. Administer for 2–3 wk after vaccine has been given.
Antiviral Treatment: Administer as soon as possible after onset of symptoms and continue for 24–48 hr after symptoms disappear.

Patient/Family Teaching ⬆ ⬇

Advise patient to take medication around the clock as directed and not to skip doses or double up on missed doses. Do not stop abruptly; may cause an increase in symptoms of Parkinson’s disease, delirium, agitation, delusions, hallucinations, paranoid reaction, stupor, anxiety, depression, or slurred speech. If a dose is missed, do not take within 4 hr of the next dose. Take next dose of ER preparations as scheduled.
- May cause sudden onset of sleep, drowsiness, or dizziness. Advise patient to avoid driving and other activities that require alertness until response to drug is known.
- Advise patient to make position changes slowly to minimize orthostatic hypotension.
- Inform patient that frequent mouth rinses, good oral hygiene, and sugarless gum or candy may decrease dry mouth. Consult health care professional if dry mouth persists for >2 wk.
- Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications, especially cold remedies, or drinking alcoholic beverages.
- Instruct patient to notify health care professional if confusion; mood changes; difficulty with urination; edema and shortness of breath; new or increased gambling, sexual, or other intense urges; or worsening of Parkinson’s disease symptoms occurs.
- Advise patient and family to notify health care professional immediately if thoughts about suicide or dying, attempts to commit suicide, or new or worse depression occur.
- Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding.
Antiviral: Instruct patient and family to notify health care professional if influenza symptoms occur when amantadine is used as prophylaxis or if symptoms do not improve in a few days when product is used for treatment.
Parkinson’s Disease: Advise patient that up to 2 wk of therapy may be needed for full benefit of medication. Notify health care professional if medication gradually loses its effectiveness. Amantadine should be tapered gradually; abrupt withdrawal may precipitate a parkinsonian crisis.

section name header

Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇