This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Which antitubercular drug is implicated in the causation of transient memory loss? 
Select and explain. 
A. Ethionamide, B. Isoniazid, C. Ethambutol, D. Pyrazinamide
B: Isoniazid
Answer: B: Isoniazid 
Explanation: The most important side effects of isoniazid include rash (2%), fever (1.2%), jaundice (0.6%) and peripheral neuritis (0.2%).
Mental abnormalities with INH include euphoria, transient impairment of memory, separation of ideas and reality loss of self-control and florid psychosis.
Ethionamide causes mental depression, drowsiness and asthenia.