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
Drug which does not interfere with folic acid metabolism? 
Select and explain. 
A. Phenytoin, B. Gabapentin, C. Phenobarbitone, D. Primidone
B: Gabapentin
Answer: B: Gabapentin 
Explanation: Ans. is `b' i.e., Gabapentin Drugs causing folate deficiency Interference with folic acid absorption Phenytoin Sulfasalazine Cotrimoxazole Inhibition of dihydrofolate reductase: Methotrexate Trimethoprim Triamterene Pentamidine Pyrimethamine Primidone Phenobarbitone Impair folate metabolism Alcohol