amifampridine (Firdapse)

Indications

• treatment of Lambert-Eaton myasthenic syndrome

Contraindications

• history of seizures

Dosage

• 15-30 mg daily, divided TID-QID
• starting dosage is 15 mg daily for patients with renal impairment, hepatic impairment, or NAT2 poor metabolizers
• maximum single dose 20 mg; maximum 80 mg/day

10 mg tablets

Adverse effects

• most common (>10%)
  • paresthesia, upper respiratory tract infection, abdominal pain, nausea, diarrhea, headache, elevated serum transaminases, back pain, hypertension, muscle spasms
• serious
  • seizures

Drug interactions

• drugs that lower the seizure threshold
• drugs with cholinergic effects
  • cholinesterase inhibitors

Mechanism of action

• K+ channel blocker

More general terms

• neurologic agent