Avoidance of fluoroquinolone, aminoglycoside and ketolide antibiotics, magnesium sulfate, chloroquine and hydroxychloroquine, penicillamine, and botulinum toxin in patients with MG is prudent. Likewise, beta blockers, procainamide, quinidine, and quinine should be avoided when possible. Other following drugs are usually well-tolerated in patients with MG but occasionally have been associated with an MG exacerbation.
Inhalation anesthetics - eg, isoflurane, halothane
Local anesthetics¶ - eg, bupivacaine, lidocaine, procaine
Antibiotics and antiviral agents
Antiretroviral agents - eg, ritonavir
Tetracyclines - eg, doxycycline, tetracycline
Macrolides - eg, azithromycin, clarithromycin, erythromycin
Antipsychotics and other psychiatric drugs
Butyrophenones - eg, haloperidol
PhenothiazinesΔ - eg, chlorpromazine, prochlorpromazine
Calcium channel blockers - eg, verapamil
Emetine (Ipecac syrup)
Iodinated contrast agents
◊ Although glucocorticoids are a common treatment for MG, at high doses they may cause a significant exacerbation of MG symptoms during early stages of treatment. For this reason, glucocorticoids should be started in high doses only in hospitalized patients who are receiving concurrent plasmapheresis or IVIG for myasthenic crisis.