Amantadine Dosing Considerations for Tremor

Special Population Considerations

For persons 65 years of age or older, the daily dosage of amantadine should be reduced to 100 mg (50 mg twice daily) due to age-related decline in renal function, as recommended by MMWR Recommendations and Reports 1
The lower dose in elderly patients helps minimize the risk of central nervous system side effects while maintaining efficacy, according to American family physician 2

For children 10-12 years of age, the recommended dosage is 100 mg twice daily, as stated by American family physician 3, 2
For children 1-9 years of age requiring amantadine, the dosage should be 5 mg/kg/day up to 150 mg in two divided doses, according to American family physician 3, 4
Children weighing less than 40 kg (88 lb) should receive 5 mg/kg/day regardless of age, divided into two doses, as recommended by American family physician 3, 5

A reduction in dosage is recommended for patients with creatinine clearance <50 mL/min/1.73m², as stated by MMWR Recommendations and Reports 1
The drug package insert should be consulted for specific dosage recommendations based on creatinine clearance, according to American family physician 6
Patients with renal impairment should be observed carefully for adverse reactions, and further dose reduction may be necessary, as recommended by MMWR Recommendations and Reports 1

Monitor for common side effects including nervousness, anxiety, insomnia, difficulty concentrating, and lightheadedness, as advised by American family physician 2

If sleep disturbances occur, avoid taking the second dose too close to bedtime, as recommended by American family physician 2

The Centers for Disease Control and Prevention, as reported in MMWR Recommendations and Reports, recommends that elderly patients (≥65 years) should be on reduced maintenance doses (≤100 mg/day) due to age-related renal decline, and tapering should be done even more cautiously in this population 7
For patients with renal impairment, the MMWR Recommendations and Reports suggests that amantadine accumulates significantly with creatinine clearance ≤50 mL/min/1.73m², and tapering should be done more slowly in proportion to the degree of renal dysfunction 7
Patients with seizure disorders or psychiatric conditions are at highest risk for severe withdrawal complications, and the MMWR Recommendations and Reports recommends considering even slower tapers with closer monitoring in these populations 7
If withdrawal symptoms occur during tapering, the MMWR Recommendations and Reports suggests waiting 1-2 weeks for stabilization after returning to the previous tolerated dose, and then resuming the taper at a slower rate 7