Penicillamine is the key drug that induces a myasthenic syndrome; it is used in the treatment of rheumatoid arthritis and Wilson's disease. It may cause a true myasthenia gravis with detectable circulating antibodies to the acetylcholine receptor. Recovery follows several months after the drug is withdrawn.
Other drugs may interfere with neuromuscular transmission either by pre-synaptic inhibition of the nerve action potential due to inhibition of calcium flux; or may induce a post-synaptic curare like blockade; or may inhibit ionic conductance across the muscle membrane. Drugs implicated include (1):
Last reviewed 01/2018