In clinical practice, many drugs have been found to cause exacerbation of myasthenia gravis symptoms and even worsen to cause critical illness. Therefore, these drugs should be used with caution or prohibited. If the condition requires it and has to be used, close cooperation should be obtained from the neurologist. These drugs are commonly available in the following categories: 1. antimicrobials: streptomycin, kanamycin, gentamicin, neomycin, tetracycline, oxytetracycline, jessamine, ampicillin, tobramycin, polymyxin B and polymyxin E, etc. The antimicrobial agents that have not been found to aggravate myasthenia gravis are: penicillin, chloramphenicol, erythromycin, dactinomycin, spiramycin, vancomycin, and vanguorin. 2, cardiovascular drugs: lidocaine, quinidine procaine amide, insulin, insulin, medoxin, aminocardium, isobaric stop, mithiafen, slow pulse, etc. 3, anti-epileptic drugs: phenytoin sodium, ethosuximide, trimethoprim, etc. 4.Anti-rheumatic drugs: penicillamine, chloroquine. 5, antipsychotics: lithium carbonate, phenelzine, promethazine, chlorpromazine, clonidine, Valium (especially injectable). 6, anesthetics: morphine, chloroform, arrow poison, ether. If the surgery must use anesthetics when available halothane, nitrous oxide (laughing gas), cyclopropane, succinylcholine, etc. 7, other: quinine, choline chloride, carnitine.