This site is intended for healthcare professionals

Go to /sign-in page

You can view 5 more pages before signing in

Drug induced myasthenic syndromes

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

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 Recovery follows several months after the drug is withdrawn.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):

  • antibiotics - aminoglycosides, tetracyclines, quinine, quinidine; perhaps the 4-quinolone antibiotics such as ciprofloxacin.
  • beta-adrenoreceptor blocking drugs
  • phenytoin
  • lithium
  • phenothiazines

Reference:

  • Newsom-Davis J (1993), Myasthenia gravis and the Lambert-Eaton myasthenic syndrome, Prescribers' Journal, 33(5): 205-11.

Related pages

Create an account to add page annotations

Add information to this page that would be handy to have on hand during a consultation, such as a web address or phone number. This information will always be displayed when you visit this page