Antihypertensive Drugs

Abstract

Q1 What should you know about ACE inhibitors?

These drugs all end in –pril. Examples are lisinopril, ramipril, perindopril and enalapril. The dose range for lisinopril in hypertension is 5–40 mg once daily. The ACE inhibitors block the conversion of angiotensin 1 to angiotensin II by inhibiting angiotensin converting enzyme. Angiotensin II is a powerful vasoconstrictor and in this way blood pressure is thought to be lowered. ACE inhibitors have antiproteinuric properties and are specifically indicated in patients with proteinuric nephropathy (urine PCR >50 mg/mmol). The commonest side effect of an ACE inhibitor is a dry cough, the occurrence of which should prompt a switch to an angiotensin receptor blocker. We have already alluded to the fact that ACE inhibitors may worsen renal function in patients with bilateral renovascular disease and also cause hyperkalaemia. This is in addition to an acute worsening of renal function if the patient becomes intravascularly deplete. Patients prescribed an ACE inhibitor must be advised to omit this drug and seek help from their general practitioner if they start vomiting or develop diarrhoea in order to reduce the risk of drug induced AKI.