Amantadine Continuation After Hospital Discharge for Acute Stroke Requiring Inpatient Rehabilitation: A Long-term Follow-up Study

Objectives

To describe the dosing strategy, safety, and effectiveness of amantadine in patients admitted to inpatient rehabilitation after stroke.

Design

Retrospective, single-center, cohort study.

Setting

Ninety-bed, inpatient rehabilitation hospital.

Participants

Twenty-eight patients (N=28) with amantadine started in a neuro-intensive care unit after stroke and continued after transfer to rehabilitation; the median age was 67 years and 61% were men.

Interventions

Oral amantadine.

Main Outcome Measures

Amantadine prescribing practices, adverse drug effects, and changes in recovery trajectory relative to dose changes.

Results

This cohort included 14 adult patients with intracerebral hemorrhage, 10 with subarachnoid hemorrhage, and 4 with acute ischemic stroke. The most common admitting amantadine dose was 100 mg twice daily. Inpatient rehabilitation lasted 27 (24-35) days, and amantadine was discontinued during rehabilitation in 6 patients (21%). Amantadine was prescribed to 22 patients (79%) at discharge from rehabilitation, most commonly 100 mg daily or twice daily, and was continued for 105 (39-510) days after admission to rehabilitation among the 17 patients with this data available. Twenty-one potential adverse events were identified among 16 (57%) patients, including confusion or delirium, sleeplessness, agitation, fatigue or lethargy, and spasticity; 8 of these (38%) occurred after reductions in amantadine dose.

Conclusions

Amantadine dosing was highly variable during inpatient rehabilitation, with trends for longer dosing after acute ischemic stroke and shorter for subarachnoid hemorrhage. Amantadine appeared well tolerated during and after inpatient rehabilitation, and most (22/28) patients were prescribed amantadine at discharge. Strategies to guide long-term use of amantadine after acute stroke require further prospective study.