Which inhalant anesthetic is historically associated with malignant hyperthermia in some dogs and pigs and is partially metabolized by the liver?

• A. Isoflurane
• B. Halothane
• C. Sevoflurane
• D. Desflurane

Answer: (B)

Malignant hyperthermia is a geneticly mediated hypermetabolic reaction of skeletal muscle that is triggered by certain volatile anesthetics. In dogs and pigs, halothane has long been the classic agent associated with MH. This historical link, combined with halothane’s notable hepatic metabolism, explains why it’s the best answer. Halothane is partially metabolized by the liver, producing reactive metabolites that can contribute to hepatotoxicity, whereas the other common inhalants are metabolized to a much lesser extent and are less historically tied to MH in these species. Thus, halothane fits both the MH trigger association and the higher hepatic metabolism described.