Fosinopril is an angiotensin converting enzyme (ACE) inhibitor

ACE inhibitor

ACE inhibitors or angiotensin-converting enzyme inhibitors are a group of drugs used primarily for the treatment of hypertension and congestive heart failure...

 used for the treatment of hypertension

Hypertension

Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...

 and some types of chronic heart failure. Fosinopril is the only phosphinate-containing ACE inhibitor marketed. It is marketed by Bristol-Myers Squibb

Bristol-Myers Squibb

Bristol-Myers Squibb , often referred to as BMS, is a pharmaceutical company, headquartered in New York City. The company was formed in 1989, following the merger of its predecessors Bristol-Myers and the Squibb Corporation...

 under the trade name Monopril.

Fosinoprilat and Fosinopril

Fosinoprilat proved to have the same problem as enalaprilat and the other carboxylate-containing ACE inhibitors (namely poor oral bioavailability

Bioavailability

In pharmacology, bioavailability is a subcategory of absorption and is used to describe the fraction of an administered dose of unchanged drug that reaches the systemic circulation, one of the principal pharmacokinetic properties of drugs. By definition, when a medication is administered...

). Addition of a hydrophobic side-chain modulated the ionisation characteristics of the molecule making it more bioavailable. Fosinopril is administered as a prodrug

Prodrug

A prodrug is a pharmacological substance administered in an inactive form. Once administered, the prodrug is metabolised in vivo into an active metabolite, a process termed bioactivation. The rationale behind the use of a prodrug is generally for absorption, distribution, metabolism, and...

and is converted in vivo to the active form fosinoprilat.