Introduction
This table provides a structured review of the main pharmacological classes used in the treatment of arterial hypertension. Each group is described according to its preferred indications, contraindications, adverse effects, and specific precautions, allowing for a comprehensive and comparative view of antihypertensive therapy.
Thiazide and thiazide-like diuretics
Include chlorthalidone, hydrochlorothiazide, indapamide, and metolazone. These are first-line drugs in many hypertensive patients, effective as monotherapy or in combination. They should be avoided in cases of active gout and used with caution in metabolic syndrome, glucose intolerance, pregnancy, and hypokalaemia.
The most frequent adverse effects include hyperglycaemia, hyperuricaemia, dyslipidaemia, and electrolyte imbalances such as hyponatraemia and hypokalaemia. They may also cause postural hypotension, dizziness, photosensitivity, and sexual dysfunction.
Angiotensin-converting enzyme inhibitors (ACE inhibitors)
Examples: captopril, enalapril, lisinopril, perindopril.
They are contraindicated in pregnancy, in cases of previous angioedema, hyperkalaemia, and bilateral renal artery stenosis.
The main adverse effects include symptomatic hypotension (especially in dehydrated patients), dry irritating cough, renal function impairment, skin rash, and angioedema, which is more frequent in Black patients.
Angiotensin II receptor antagonists (ARBs)
Include losartan, valsartan, candesartan, and telmisartan.
They share many features with ACE inhibitors and are a useful alternative when cough occurs with ACE inhibitor therapy. However, they maintain the risk of hyperkalaemia and renal impairment, and are also contraindicated in pregnancy and in bilateral renal artery stenosis.
Calcium channel blockers
Dihydropyridines — such as amlodipine, nifedipine, and lercanidipine — rarely have absolute contraindications. They may cause peripheral oedema, flushing, headache, and mild gastrointestinal symptoms.
Non-dihydropyridines — verapamil and diltiazem — should be avoided in heart failure with reduced ejection fraction and when combined with beta-blockers, due to the risk of bradycardia and conduction blocks.
Loop diuretics
The most commonly used are furosemide and torasemide.
They are more effective in patients with heart failure or renal dysfunction but require close monitoring.
Adverse effects include hyponatraemia, hypokalaemia, dehydration, ototoxicity, and metabolic disturbances such as hyperglycaemia and hyperuricaemia.
Potassium-sparing diuretics
Include spironolactone and eplerenone, useful in heart failure with reduced ejection fraction.
Contraindications include eGFR < 30 mL/min, hyperkalaemia, and Addison’s disease.
The most relevant adverse effects are hyperkalaemia, gynaecomastia, menstrual irregularities, muscle weakness, and skin pruritus.
Beta-blockers
Divided into cardioselective (atenolol, bisoprolol, metoprolol, nebivolol), non-selective (propranolol), and with additional alpha-blocking action (carvedilol).
They should be avoided in marked bradycardia, second- or third-degree atrioventricular block, severe asthma, and decompensated heart failure.
Adverse effects include fatigue, sleep disturbances, sexual dysfunction, cold extremities, and occasionally worsening of heart failure.
Although not first-line agents for isolated hypertension, they play a key role in patients with stable angina, post-myocardial infarction, and stable chronic heart failure.
Conclusion
The choice of antihypertensive agent should be individualized, taking into account comorbidities, renal function, electrolyte balance, and potential interactions.
Regular clinical and laboratory monitoring is essential to optimize therapeutic efficacy and prevent complications.
