The 2021 WHO hypertension guideline aims to provide the most current and relevant evidence based global public health guidance on the initiation of treatment (with pharmacological agents) for hypertension in adults.

The recommendations target adult, non-pregnant patients who were appropriately diagnosed with hypertension and counseled about life-style modifications.

The guideline provides new recommendations on the threshold for the initiation of pharmacological treatment for hypertension, as well as recommendations on intervals for follow up, target blood pressure to be achieved for control, and the cadre of health care workers who may initiate treatment.

The guideline provides the basis for deciding whether to initiate treatment with monotherapy, dual therapy or single-pill combinations, as well as guidance for countries selecting medicines and algorithms for hypertension control for their national guidelines for hypertension management.

RECOMMENDATION ON BLOOD PRESSURE THRESHOLD FOR INITIATION OF PHARMACOLOGICAL TREATMENT

WHO recommends initiation of pharmacological antihypertensive treatment of individuals with a confirmed diagnosis of hypertension and systolic blood pressure of ≥140 mmHg or diastolic blood pressure of ≥90 mmHg.

WHO recommends pharmacological antihypertensive treatment of individuals with existing cardiovascular disease and systolic blood pressure of 130–139 mmHg.

WHO suggests pharmacological antihypertensive treatment of individuals without cardiovascular disease but with high cardiovascular risk, diabetes mellitus, or chronic kidney disease, and systolic blood pressure of 130–139 mmHg.

Initiation of pharmacological hypertension (HTN) treatment should start no later than four weeks following diagnosis of HTN. If blood pressure level is high (e.g. systolic ≥160 mmHg or diastolic ≥100 mmHg) or there is accompanying evidence of end organ damage, initiation of treatment should be started without delay.

RECOMMENDATION ON DRUG CLASSES TO BE USED AS FIRST-LINE AGENTS

For adults with hypertension requiring pharmacological treatment, WHO recommends the use of drugs from any of the following three classes of pharmacological antihypertensive medications as an initial treatment:

·       thiazide and thiazide-like agents

·       angiotensin-converting enzyme inhibitors (ACEis)/angiotensin-receptor blockers (ARBs)

·       long-acting dihydropyridine calcium channel blockers (CCBs)

Long-acting antihypertensives are preferred. Examples of indications to consider specific agents include diuretics or CCBs in patients over 65 years or those of African descent, beta-blockers in ischaemic heart disease, ACEis/ARBs in patients with severe proteinuria, diabetes mellitus, heart failure or kidney disease.

RECOMMENDATION ON COMBINATION THERAPY

For adults with hypertension requiring pharmacological treatment, WHO suggests combination therapy, preferably with a single-pill combination (to improve adherence and persistence), as an initial treatment.

Antihypertensive medications used in combination therapy should be chosen from the following three drug classes: diuretics (thiazide or thiazide-like), angiotensin-converting enzyme inhibitors (ACEis)/angiotensin-receptor blockers (ARBs), and long-acting dihydropyridine calcium channel blockers (CCBs).

Combination medication therapy may be especially valuable when the baseline BP is ≥20/10 mmHg higher than the target blood pressure.

Single-pill combination therapy improves medication-taking adherence and persistence and BP control.

RECOMMENDATION ON TARGET BLOOD PRESSURES

·       WHO recommends a target blood pressure treatment goal of <140/90 mmHg in all patients with hypertension without comorbidities.

·       WHO recommends a target systolic blood pressure treatment goal of <130 mmHg in patients with hypertension and known cardiovascular disease (CVD).

·       WHO suggests a target systolic blood pressure treatment goal of <130 mmHg in high-risk patients with hypertension (those with high CVD risk, diabetes mellitus, chronic kidney disease).

Drug- and dose-specific protocols

Initiation of treatment with a single-pill combination

Beginning treatment with two antihypertensive drugs from different classes is recommended when baseline BP is ≥20/10 mmHg above goal, and should be considered when baseline BP is
≥140/90 mmHg.

Drugs affecting the renin–angiotensin system (ACEis, ARBs, and aliskiren) have been associated
with serious fetal toxicity, including renal and cardiac abnormalities and death; they are
contraindicated for use during pregnancy

This protocol is contraindicated for women who are or could become pregnant. Neither an ACEI or ARB should be given to pregnant women.

Initiation of treatment not using a single-pill combination (i.e. with monotherapy
or free combination therapy)

A CCB, rather than a thiazide-type diuretic or ACEi/ARB, was selected as first-line medication
if one agent is used, to avoid the need for electrolyte measurements or to alleviate concerns
regarding potential change in GFR.

Drugs affecting the renin-angiotensin system (ACEis, ARBs, and aliskiren) have been associated
with serious fetal toxicity, including renal and cardiac abnormalities and death; they are
contraindicated for use during pregnancy.