Know the common side effects of commonly used antihypertensive drugs.😎😎😎

Angiotensin converting enzyme inhibitors (ACEI), angiotensin II receptor antagonists (ARB), β receptor blocker, dihydropyridine calcium channel blockers (CCB) and diuretics are used commonly antihypertensive drugs in clinical. These antihypertensive drugs have their own characteristics, priority indications and adverse effects.

1. Angiotensin converting enzyme inhibitors (ACEI)

Common drugs: Captopril, enalapril and lisinopril.

Mechanism: It inhibits angiotensin-converting enzyme and block the production of renin-angiotensin II. It also inhibit the degradation of bradykinin and cause a hypotensive effect.

• Adding diuretics or limiting salt intake can increase the antihypertensive effect of ACEI.

Priority indications: Hypertensive patients with chronic heart failure, cardiac insufficiency after myocardial infarction, prevention of atrial fibrillation, metabolic syndrome, diabetic nephropathy, non-diabetic nephropathy, proteinuria or microalbuminuria.

Adverse effects: 

1. Dry cough: About 30% of patients can cause a persistent dry cough. It often gets worse after lying down. Non-smokers and women are more likely to develop dry coughs. Dry cough may be related to increased bradykinin and prostaglandin levels. Non-steroidal anti-inflammatory drugs inhibit prostaglandin synthesis. They can suppress coughing, but increase the risk of kidney damage.
2. Angioedema: It can affect the tongue, glottis, or larynx. It usually occurs within a few hours or 1 week after the medication. If angioedema occurs, patients should be discontinued using ACEI.
3. Hyperkalemia: Bradycardia, nausea and fatigue are the early manifestations. Patients with diabetes and renal insufficiency are more likely to occur.

2. Angiotensin II receptor antagonists (ARB)

Common drugs: Losartan, valsartan, olmesartan and irbesartan.

Mechanism: It blocks angiotensin II receptor (type 1). It cause decreasing secretion of vasopressin, decreasing synthesis and secretion of aldosterone. That exerts vasodilation and antihypertensive effect.

Priority indications: Patients can not tolerate ACEI who can choose ARB.

Adverse effects: 

1. Back pain: ARB antihypertensive drugs can cause back pain. The results of clinical trials showed that the incidence of back pain caused by valsartan was 1.6% and the incidence of joint pain was 1.0%. Different ARB drugs have different incidences of adverse effects in the musculoskeletal system. If musculoskeletal pain occurs when  taking a ARB drug, you can try to alter another ARB drug.
2. Hyperkalemia: Both ACEI and ARB antihypertensive drugs can cause hyperkalemia.

3. β receptor blocker

Common drugs: Metoprolol and atenolol.

Mechanism: It inhibits β receptor. It lead to inhibit myocardial contractility and slow down the heart rate. Therefore, it produces a hypotensive effect.

Priority indications: Patients with tachyarrhythmia, coronary heart disease and chronic heart failure.

Adverse effects: 

1. Slow heartbeat and pulse: β-blockers have greatly variance among individuals and patients should monitor their heart rate. For patients with hypertension and coronary heart disease, the resting heart rate should be slowed down to 50-60 beats/min while controlling blood pressure.
2. Rebound phenomenon: Sudden discontinuation of β blockers can cause severe angina pectoris and even sudden cardiac death. The dose must be gradually reduced under the guidance of a doctor and the entire withdrawal process should take at least 2 weeks.

4. Dihydropyridine calcium channel blockers (CCB)

Common drugs: Felodipine, nifedipine and amlodipine.

Mechanism: It can inhibit the calcium channel on vascular smooth muscle cells. Therefore, it can lead to dilate blood vessels and lowering blood pressure.

Priority indications: Elderly patients with hypertension or isolated systolic hypertension  associated with coronary and carotid atherosclerosis, stable angina and peripheral vascular disease.

Adverse effects: 

1. Constipation: All dihydropyridine calcium channel blockers can cause constipation.
2. Gingival hyperplasia: Felodipine, nifedipine, amlodipine and so on can cause gingival hyperplasia.
3. Increased heart rate: Calcium channel blockers can reflexively cause tachycardia. It can worse heart failure. Except for felodipine and amlodipine, other calcium channel blockers are not recommended for the treatment of patients with hypertension and heart failure.
4. Ankle edema: It is related to the dosage. Elevating the foot can reduce the symptoms of edema. Mainly due to the expansion of the precapillary arterioles, not due to fluid retention. Combined use of ACEI or ARB can reduce the symptoms of edema.

5. Diuretics (Thiazides diuretics)

Common drugs: Chlorothiazide, hydrochlorothiazide and indapamide.

Mechanism: It acts on the ascending limb of Henle's loop and the distal convoluted tubules in the renal cortex. It increases to excrete sodium and urine and reduce blood volume.

Priority indications: Elderly hypertension, isolated systolic hypertension, refractory hypertension, etc.

Adverse effects: 

1. Photosensitivity: It can cause skin rash. Patients taking thiazide diuretics should avoid direct sunlight.
2. Hypokalemia: The main symptoms include nausea, anorexia and fatigue. It can be improved when combined with antihypertensive drugs that may cause hyperkalemia such as ACEI and ARB, but electrolyte levels still need to be monitored regularly.
3. Hyperuricemia: Patients with gout should prohibit using thiazide diuretics. If the blood uric acid level is ≥480μmol/L, it is recommended to change to other antihypertensive drugs.
4. Hypercalcemia: Patients should be cautious when using it in combination with calcium and vitamin D supplements. Thiazide diuretics can reduce urinary calcium excretion and may cause hypercalcemia.

6. Diuretics (Loop diuretics)

Common drugs: Furosemide.

Mechanism: It inhibits the cotransporter of Na⁺⁄ 2Cl^-⁄ K⁺ in the ascending limb of Henle's loop. It reduces the recycle of Na⁺, K⁺ and Cl^- to achieve diuretic effect.

Priority indications: It can take effect quickly. Therefore, it can be used for patients with acute edema symptoms.

Adverse effects: 

1. Hypokalemia and hyperuricemia: Similar to thiazide diuretics.
2. Ototoxicity: Loop diuretics may cause ototoxicity. Be careful when combining with other ototoxic drugs (such as aminoglycoside antibiotics).

7. Diuretics (Potassium-sparing diuretics)

Common drugs: Spironolactone, eplerenone and amiloride.

Mechanism: Spironolactone and eplerenone can antagonist aldosterone. Amiloride blocks sodium ion channels and produces effects similar to aldosterone antagonists.

Priority indications: It often combined with thiazides diuretics or loop diuretics. Aldosterone antagonists usually effect to resistant hypertension (It refers to use 3 or more types of antihypertensive drugs still not achieve the target blood pressure).

Adverse effects: 

1. Hyperkalemia: It can decrease to excrete potassium in urine. Be careful when combined with the drugs that may cause hyperkalemia such as ACEI and ARB.
2. Gynecomastia and Irregular menstrual periods: The chemical structure of spironolactone is similar to some sex hormones. Therefore, spironolactone may cause gynecomastia and Irregular menstrual periods.