Initial Antihypertensive Therapy

Initial antihypertensive therapy begins once hypertension is confirmed by ambulatory or home measurement and the person’s total cardiovascular risk is known. Drug treatment starts at once for confirmed pressure of 160/100 mmHg or over, or at 140 to 159/90 to 99 mmHg when there is diabetes, chronic kidney disease, established cardiovascular disease, target organ damage or a 10 year cardiovascular risk of 10% or more. Lower-risk people with stage 1 hypertension may have lifestyle measures for 3 to 6 months first.

Lifestyle. Salt intake under 5 g daily, weight loss, regular exercise, limited alcohol and potassium-rich food in the absence of kidney disease. Lifestyle measures never delay drug treatment when pressure is 160/100 mmHg or over.

Pregnancy potential. Ask about pregnancy before choosing a drug, since ACE inhibitors and angiotensin receptor blockers cause foetal harm.

Default first step. For people under 55 years who are not of African ancestry, start an ACE inhibitor: ramipril 2.5 mg orally once daily, increased after 2 to 4 weeks to 5 mg and then 10 mg daily. Use an angiotensin receptor blocker if cough occurs: losartan 50 mg orally once daily, maximum 100 mg daily.

Age 55 or over or African ancestry. Start amlodipine 5 mg orally once daily, maximum 10 mg daily. If ankle oedema prevents use, give indapamide modified-release 1.5 mg orally once daily.

Two drugs from the start. If pressure is 20/10 mmHg or more over target, begin two drugs together, preferably as a single pill.

Special groups. In older adults start amlodipine at 2.5 mg or ramipril at 1.25 mg and increase every 4 weeks. In creatinine clearance under 30 mL/min, limit ramipril to 5 mg daily. In hepatic impairment start amlodipine at 2.5 mg. In people with diabetes and albuminuria start an ACE inhibitor or angiotensin receptor blocker. In East Africa, cost and supply decide the class within these options, and fixed-dose once-daily products improve adherence.

Review. Recheck pressure at 4 weeks, increase the dose, then add a second class if target is not reached by 3 months.

Monitoring. Creatinine, potassium and sodium 1 to 2 weeks after starting an ACE inhibitor, angiotensin receptor blocker or diuretic. Ask about cough, ankle swelling, dizziness and erectile dysfunction.

Home readings. Use the average of two morning and two evening readings over 4 to 7 days.

Stopping. Stop an ACE inhibitor for angioedema, potassium over 6.0 mmol/L, or a creatinine rise over 30% that persists. Reduce amlodipine for troublesome oedema before stopping it.

Common errors. Starting a beta blocker without an indication, treating a single clinic reading, stopping a drug for a minor adverse effect without switching, and not repeating bloods.

Referral and escalation. Refer early for young onset hypertension, hypokalaemia at diagnosis (suspected primary aldosteronism), episodic symptoms (suspected phaeochromocytoma), or a creatinine rise over 30% after an ACE inhibitor (suspected renal artery stenosis).