Quinapril

Indications

Quinapril is used for: Hypertension, Heart failure

Adult Dose

Oral Hypertension Adult: Initially, 10 or 20 mg once daily, 1st dose preferably at bedtime or alternatively in 2 divided doses. Maintenance: 20-80 mg/day as a single dose or in 2 divided doses. Patients on diuretics: Initially, 5 mg once daily. Close monitoring is required until BP has stabilised. If possible, diuretic should be discontinued 2-3 days before starting therapy w/ ACE inhibitor. Heart failure Adult: As adjunct: Initially, 5 mg bid. Dosage may be adjusted at wkly intervals to 20-40 mg in 2 divided doses if initial dose is tolerated.

Child Dose

Renal Dose

Renal impairment: CrCl (ml/min) Dosage Recommendation 10-30 Initial: 2.5 mg once daily. >60 Initial: 10 mg once daily. 31-60 Initial: 5 mg once daily.

Administration

Should be taken on an empty stomach. Take before meals at about the same time of day.

Contra Indications

History of angioedema related to previous ACE inhibitor treatment, hereditary or idiopathic angioedema. Concomitant use w/ aliskiren in patients w/ diabetes and renal impairment. Pregnancy.

Precautions

Patients w/ diarrhoea, severe volume and/or salt depletion due to prolonged use of diuretics and unilateral or bilateral renal artery stenosis. Patients on dietary salt restriction and dialysis. Severe CHF. Increased risk of angioedema in black patients. Renal and hepatic impairment. Lactation. Monitoring Parameters Monitor BP prior and throughout therapy. Periodically monitor serum creatinine, K levels and CBC.

Pregnancy-Lactation

Interactions

Additive hyperkalaemic effects w/ K-sparing diuretics, K supplements, other drugs that can cause hyperkalaemia. Increased lithium concentrations and toxicity. May decrease absorption of tetracyclines. May increase nitritoid reactions of gold Na thiomalate. Potentially Fatal: Increased risk of hypotension, hyperkalaemia and nephrotoxicity w/ concomitant aliskiren in renally impaired and diabetic patients.

Adverse Effects

Side effects of Quinapril : Dizziness, headache, fatigue, persistent dry cough and other upper resp tract symptoms, skin rashes, hyperkalaemia, chest pain, cholestatic jaundice, nausea, vomiting, neutropenia, agranulocytosis, dyspnoea, diarrhoea, myalgia, back pain, increased serum creatinine and BUN. Potentially Fatal: Anaphylactic reactions including angioedema. Pronounced hypotension. Fulminant hepatic necrosis.

Mechanism of Action

Quinapril is a prodrug of quinaprilat. It is a competitive inhibitor of ACE. It prevents conversion of angiotensin I to angiotensin II (a potent vasoconstrictor) resulting in lower levels of angiotensin II which causes an increase in plasma renin activity and a reduction in aldosterone (a potent vasoconstrictor) secretion. This promotes vasodilation and BP reduction.