Effect of Calcium Pantothenate on Isoniazid Toxicity in the Guinea Pig. ∗,†

Summary

1. Administering 50-75 mg/kg of isoniazid 3 times a week to the guinea pig produces a transient peripheral neuropathy characterized by initial hyperreflexia and hyperesthesia particularly evident in limb joints. An extensive muscle flaccidity of 3-4 hours duration also occurs during this reaction to isoniazid. 2. Addition of 1.2 g/kg of ethanol to the isoniazid injection significantly increases incidence of the toxic response to isoniazid. 3. The response is prevented by daily administration of 20 mg/kg of calcium pantothenate but is not prevented by daily administration of 20 mg/kg of pyridoxal HCl.