Management of hypertension Blood pressure treatment targets

Management of hypertension

Blood pressure treatment targets

Antihypertensive pharmacotherapy

Antihypertensive medications are gradually evolving and they are reducing CVD morbidity and mortality. Antihypertensive medications start with first-line antihypertensives either in monotherapy or in combinations. First-line antihypertensive medications are ACE inhibitors, Angiotensin II receptor blockers, dihydropyridine calcium channel blockers, and thiazide diuretics. Beta-blockers are also included in first-line antihypertensive drugs. It is used in patients with heart failure and reduced ventricular ejection. The choice of first-line drugs should be based on the efficacy and tolerability of the patients. For example in gestational hypertension medications such as alpha-methyldopa or labetalol are preferable. In some cases, ACE inhibitors and angiotensin II receptor blockers, are contraindicated because of their potential risk for renal teratogenicity. When antihypertensives are given in divided doses, adherence is mostly interrupted, so it should be avoided whenever possible. In severe hypertensive patients, blood pressure can not be controlled with a single medication. So while going for combining therapy its side effects, additive effects on blood pressure and patient’s comorbidities should be kept in mind.

Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers

ACE inhibitors and angiotensin II blockers are considered first-line antihypertensives. A large number of studies are supporting the effectiveness of ACE inhibitors and angiotensin II receptor blockers. These medications are the preferred drug of choice in patients with heart failure with reduced ventricular ejection. ACE inhibitors and angiotensin II receptor blockers reduce CVD risk in comparison with other drugs.  These are also preferable drugs in younger patients, type-2 diabetes mellitus patients.  They reduce kidney function, hyperkalemia, and cough. ACE inhibitors can be taken in one dose in a day.

Dihydropyridine calcium channel blockers

• Dihydropyridine calcium channel blockers block Smooth muscle calcium channels. Thus it produces a vasodilatory effect.
• They have been tested in many clinical trials.
• It can be given with a combination of other first-line antihypertensive drugs.
• It can reduce heart rate, cardiac contractility and peripheral oedema may appear.
• In old age, constipation may be seen.

Thiazide-type and thiazide-like diuretics

Thiazide diuretics reduces sodium absorption. The fluid loss increased through urination. It decreases extracellular fluid and plasma volume. So there is a decrease in venous return, reduced cardiac output, and a decrease in blood pressure. Thiazides usage can produce diabetes mellitus. It also produces side effects like hypokalemia, hyponatremia, cardiac arrhythmias, muscle weakness, confusion, seizure, and coma.

Beta-adrenoreceptor blockers

beta-adrenoreceptor blockers decrease blood pressure reducing cardiac output, heart rate, and renin release. These medications are useful in acute myocardial patients. It has an adverse effect on body weight. It induces constriction of the bronchus, so it should not be used in asthmatic patients. Beta-blockers should not be given in combination with non-dihydropyridine calcium channel blockers. This combination lowers atrioventricular conduction.

Newer pharmacological agents for hypertension

Constant research trials have developed new antihypertensive medications. A combination of newer approved drugs are: angiotensin II receptor and neprilysin inhibitors (for heart failure) soluble guanylyl cyclase modulating drugs (for erectile dysfunction) sodium-glucose cotransporter 2 (SGLT2) inhibitors (for type 2 diabetes mellitus) Some newer agents have shown their effectiveness in resistant hypertension.

Treatment of resistant hypertension

Resistant hypertension is a condition in which BP is >140/90 mmHg despite treatment with two or more antihypertensive drugs including diuretics. The main cause of resistant hypertension is poor adherence to the treatment. It requires adding 1 or two more drugs to the treatment regimen for controlling blood pressure. The PATHWAY trial was conducted among resistant hypertensive patients. Sequential addition of a mineralocorticoid receptor antagonist followed by a loop diuretic was more effective than providing three drugs. Mineralocorticoid receptor antagonism was found to be an effective drug in resistant hypertension. The patient receiving this group drug has the risk of developing hyperkalemia, so serum potassium concentration should be regularly monitored.

Non-pharmacological management of hypertension

Taking preventive measures is the most effective intervention for hypertension. Lifestyle modification is recommended for all hypertensive patients. Some of the lifestyle modification advice is given below:

Reduced salt intake:

• Take salt equal to the amount that is lost in a day.
• WHO recommended <5 g of salt in a day.
• American Society of Hypertension has recommended 3.8 g salt use in a day.
• Currently, an average of 9 g-12 g of salt is used in most countries.

A study was conducted by F J He and G A MacGregor on ‘ Effect of modest salt reduction on blood pressure: a meta-analysis of randomized trials. Implications for public health’. They found that reduced sodium intake has an association with a reduction of blood pressure.

Increased potassium intake:

Healthy individuals need to take 4.7 g of potassium in a day. An increase in potassium intake has been associated with lower blood pressure. The best strategy to increase potassium intake is by increasing the consumption of fruits and vegetables.

Moderate alcohol consumption

Alcohol intake of fewer than 2 drinks per day in men and 1 drink per day in women also reduces blood pressure up to 2-4 mmHg.

Physical activity

• Doing some physical activities daily also reduces blood pressure.
• Endurance training is also effective for hypertensive patients.
• A recent clinical trial suggests that regular medium-intensity to high-intensity aerobic activity reduced BP by a mean of 11/5 mmHg.

Weight loss

Excess adipose tissue in the body increases blood pressure. It has been found that obese patients require more antihypertensive drugs to control their blood pressure.

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