FIRDAPSE® (amifampridine) is an oral potassium channel blocker primarily used in the treatment of Lambert-Eaton Myasthenic Syndrome (LEMS). It works by inhibiting potassium channels on nerve terminals, thus increasing the release of acetylcholine at the neuromuscular junction, which in turn helps to improve muscle strength and reduce fatigue associated with LEMS. FIRDAPSE® is often prescribed when standard therapies fail to provide adequate symptom relief, offering an alternative treatment option for this challenging condition.

FIRDAPSE® is typically initiated with a low dose, which is titrated based on individual patient tolerance and response. The starting dose is generally between 15 mg to 30 mg daily, with gradual increments. The maximum dosage is restricted to 80 mg per day to minimize the risk of adverse reactions, particularly seizures, which are a known side effect of the medication. Adjustments in dosage are also recommended for patients with renal or hepatic impairments or those identified as poor metabolizers of N-acetyltransferase 2 (NAT2).