Valsartan with hydrochlorothiazide

How it works

Valsartan blocks the angiotensin-II type-1 receptor to produce vasodilatation and reduce sodium-retaining aldosterone effects, while hydrochlorothiazide inhibits the distal tubular sodium-chloride co-transporter to promote natriuresis, giving additive blood-pressure reduction.

Prescribing in practice

• The combination is contraindicated in pregnancy because ARBs can cause serious foetal harm, so it must be stopped if pregnancy is planned or confirmed.
• Thiazide can lower potassium and sodium and raise urate and glucose, while valsartan tends to raise potassium, and concurrent NSAIDs increase the risk of acute kidney injury.
• Avoid combining with another renin-angiotensin blocker, and use caution in renal artery stenosis, volume depletion and significant renal impairment.

Monitoring

Check renal function and serum electrolytes before starting and periodically during treatment, particularly after dose changes or intercurrent illness.

Counselling the patient

• Stop the tablet and seek advice if you become pregnant or are planning pregnancy.
• Report dizziness, cramps or weakness suggesting an electrolyte problem.
• Avoid regular over-the-counter anti-inflammatory painkillers unless advised.

Evidence & guidelines

ARB plus thiazide combinations are well-established antihypertensive therapy, and NICE guidance supports stepwise combination treatment to achieve blood-pressure targets.