Assessing and adjusting drug therapy for blood pressure reduction
To allow time for optimal effects of the initial therapy, changes to drug therapy should be considered 4 to 6 weeks after starting treatment for elevated blood pressure (BP). For patients with high ASCVD risk or very high BP, changes to drug therapy may be considered sooner.
Review the patient for adverse effects and adherence to therapy, and to determine whether the BP treatment target has been reached with the initial drug(s). See Measurement of blood pressure for information on accurate measurement of BP. If the patient does not tolerate a drug, change to a drug from a different class.
If the BP target has been reached and the patient is stable, reassessment should be individualised.
For patients started on monotherapy, if the BP target has not been reached after 4 to 6 weeks, do not stop or change the initial drug, but add a low dose of a second drug from a different class—see Drugs used for blood pressure reductionLasserson, 2011. This is usually more effective than increasing the dose of the initial drug.
For patients taking 2 drugs, if the BP target has not been reached and the drugs are well tolerated, increase the dose of one of the drugs incrementally to the maximum dose, then increase the dose of the second drug, if required.
If BP remains above the target 4 to 6 weeks after adjusting therapy, before adding a third drug, consider other factors such as nonadherence, or secondary causes such as concomitant drugs that increase BP (see Secondary hypertension).
The following drug combinations are effective and pharmacologically complementary:
- an ACEI or ARB with a thiazide or thiazide-like diuretic
- an ACEI or ARB with a calcium channel blocker
- an ACEI or ARB with a dihydropyridine calcium channel blocker and a thiazide or thiazide-like diuretic.
Some combinations are available as fixed-dose combination products, which can help reduce the pill burden and improve adherence1. The combination of an ACEI with an ARB is not recommended except with specialist advice.
If treatment with a combination of tolerated first-line therapies does not adequately reduce BP, add a second-line drug and consider screening for secondary causes of hypertension (if not already investigated). The choice of second-line drug depends on both drug and individual patient factors—see Drugs used for blood pressure reduction.
Avoid the combination of a beta blocker and verapamil or diltiazem because of the risk of heart block.