For a hypertensive patient who remains hypertensive despite taking lercanidipine 10 mg (a calcium-channel blocker) and losartan 100 mg (an angiotensin II receptor blocker), the next step is to add a thiazide-like diuretic, such as indapamide, to their treatment regimen. This combination of an ACE inhibitor or ARB, a CCB, and a thiazide-like diuretic constitutes step 3 treatment for hypertension according to NICE guidelines.
If blood pressure remains uncontrolled despite optimal tolerated doses of these three drugs, the patient is considered to have resistant hypertension. At this stage, confirm elevated blood pressure with ambulatory or home monitoring, assess adherence, and consider adding a fourth antihypertensive drug.
For the fourth drug, if the patient's blood potassium level is 4.5 mmol/L or less, low-dose spironolactone (a potassium-sparing diuretic) is recommended, with caution in those with reduced renal function due to hyperkalaemia risk. If potassium is above 4.5 mmol/L, an alpha-blocker or beta-blocker may be considered.
If blood pressure remains uncontrolled despite four drugs at optimal doses, specialist referral is advised.