Compassionate Use of 3,4-Diaminopyridine

Drug: 3,4-diaminopyridine
Compassionate use of 3,4-DAP for patients with Lambert Eaton myasthenic syndrome (LEMS)
Other Name: DAP
Drug: 3,4-diaminopyridine
Compassionate use of 3,4-DAP for patients with congenital myasthenic gravis (CMG)
Other Name: DAP

The diagnosis of LEMS or CMG will have been made based on clinical and electromyographic findings, and all patients will have been referred to the PI for DAP treatment. This study will enroll minors and adults.

CMG patients under age 18 will be included if their parent or guardian gives written permission. Minors who turn 18 while on the study will be re-consented as adults.

The dose of DAP will be determined individually for each patient. Adults will start with a dose of 10 mg 3 or 4 times a day, increasing over several weeks to the dose that produces the maximum symptomatic response, not to exceed 100 mg/day. Mestinon will then be added at low doses, increasing to the dose that produces the best response, not to exceed 360 mg/day. In children, equivalent doses of these medications will be given calculated on a surface area basis. The doses of DAP and Mestinon will be periodically adjusted to assure that the smallest effective doses are used.

Patients who achieve significant clinical benefit from DAP, as judged by the study PI and the patient, may continue taking DAP as long as the drug is available from the sponsor, and as long as they return for regular follow-up at the Duke MG Clinic. Patients who are unable to return for regular follow-up will be required to have their local physician obtain DAP for them from the sponsor.