The nitrates which can undergo the ﬁrst-pass metabolism:: (A) Nitroglycerine, (B) Pentaerythritol tetranitrate, (C) Isosorbide dinitrate, (D) All of the above
Answer is D. Organic nitrates are lipid-soluble: well absorbed from buccal mucosa, intestines and skin. Ingested orally, all except isosorbide mononitrate undergo extensive and variable first pass metabolism in liver.They are rapidly denitrated by a glutathione reductase and a mitochondrial aldehyde dehydrogcnase.
 
Reference: Essentials of Medical Pharmacology Eighth Edition KD TRIPATHI page no 587