▾ Fosinopril (staril) – another ace inhibitor

Squibb describe fosinopril as the first of ‘a new class of ACE inhibitor designed and developed for the elderly hypertensive’. It is a pro-drug which is rapidly hydrolysed to the active fosinoprilat. This differs chemically from other ACE inhibitors in that the group which binds to the zinc ion in angiotensin converting enzyme (ACE) is phosphinic acid, instead of sulphydryl as in captopril or carboxylic acid as in enalaprilat and others. The molecule is larger and somewhat more lipophilic than those of earlier ACE inhibitors, and this may explain why a higher proportion is eliminated by the liver.