Core pharmacology

Class Group

ACE inhibitor

Legacy Cicm Level

Level 3

Introduction

active drug converted to active metabolites. It is a competitive ACE inhibitor

Indications Uses

used for management of hypertension, LV dysfunction post-myocardial infarction and in the setting of heart failure. Its use has been shown to decrease progression of heart failure (disease modifying)

Presentation

oral formulation presented as white tablets in dosage ranging from
12.5mg to 50mg

Mechanism of action

Competitive inhibition of angiotensin converting enzyme leads to decreased angiotensin II production and its effects.

Onset Peak Duration

moderately potent

Physiological effects

CVS
- TPR and Afterload is decreased to a greater extent than preload, and this may result in improved CO in heart failure patients.
- HR is usually unchanged and baroreceptor reflexes also
unchanged.

Renal
- the impairment of Ang-II means that the body is less able to respond to a drop in renal perfusion and this may precipitate failure.

Metabolic
– Accumulation of K+ may occur due to decreased aldosterone.

Adverse Effects Toxicity

A dry cough may occur especially in patients with pre-existing lung disease.
Caution should be exercised in patients on potassium sparing medications. NSAIDs may precipitate renal failure.

Absorption

PO. rapidly absorbed, BA: 60-70%

Protein binding

25%

Volume of distribution

2 L/kg

Metabolism

oxidised in the liver and converted to sulphides

Excretion

urine both as active metabolites and unchanged

Half-life

2-4 hours

Route And Dose

PO: doses commenced at 6.25mg TDS and uptitrated