3,4-Diaminopyridine (amifampridine) for the treatment of Lambert-Eaton myasthenic syndrome

作者：Lindquist Sabine^*; Stangel Martin

来源：Expert Opinion on Orphan Drugs, 2014, 2(3): 293-300.

DOI：10.1517/21678707.2014.887464

• 3,4-diaminopyridine
• amifampridine
• Lambert-Eaton myasthenic syndrome
• potassium channel blocker
• symptomatic treatment

Introduction: Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disorder of the neuromuscular junction resulting in muscle weakness and autonomic symptoms. LEMS often occurs as a paraneoplastic disease. Hallmarks of the disease are pathogenic antibodies against voltage-gated calcium channels, which cause a decrease in presynaptic acetylcholine release. 3,4-Diaminopyridine (3,4-DAP) is a potassium channel blocker, which leads to an increase of presynaptic calcium and improves the release of acetylcholine in LEMS patients. %26lt;br%26gt;Areas covered: Here, the role of 3,4-DAP for the treatment of LEMS is reviewed. A literature search was carried out for the terms %26apos;3,4-diaminopyridine%26apos; and %26apos;Lambert-Eaton myasthenic syndrome%26apos;. The information updates a previous review on the topic. %26lt;br%26gt;Expert opinion: Small placebo-controlled studies have shown the efficacy of 3,4-DAP to treat muscle weakness in LEMS patients. A larger drug withdrawal study analyzing 30 patients on stable treatment with 3,4-DAP is under way. The efficacy of 3,4-DAP is moderate. There is a need to study the additional effects of pyridostigmine, a drug inhibiting acetylcholine breakdown used in myasthenia gravis, and the potential of novel calcium channel agonists. Apart from treating LEMS symptoms, 3,4-DAP may also be beneficial in the treatment of congenital myasthenic syndromes and myasthenia gravis caused by anti-muscle-specific kinase-antibodies.

• 出版日期2014-3