Hypertension Blog

Many drugs for hypertension can increase blood pressure or interfere with other drugs used to treat hypertension. Oral contraceptives, for example, cause a small increase in systolic and diastolic blood pressure. Hypertension is two to three times more common in patients who use oral contraceptives for more than 5 years than in patients who haven’t used them at all. A patient who uses oral contraceptives has an increased risk of developing hypertension, with increasing age, duration of use, and body weight.

Estrogen, when used as a postmenopausal replacement therapy, increases blood pressure in some women. All women receiving hormone replacement therapy should have their blood pressure routinely monitored.

Cyclosporine, which is used as an immunosuppressant to prevent organ rejection in transplant recipients, causes vasoconstriction and reduces renal blood flow. Cyclosporine also increases the reabsorption of sodium, water, and urea and has a direct toxic effect on the nephrons. Vasoconstriction and sodium retention lead to hypertension in 50% to 70% of organ transplant recipients taking cyclosporine and in about 20% of nontransplant patients taking the drug for other reasons. Similarly, corticosteroids used to produce immunosuppression in organ transplant recipients can cause hypertension.

Monoamine oxidase (MAO) inhibitors, which are used for treating depression, can cause a severe hypertensive crisis. This condition results from an interaction of the MAO inhibitors with foods such as cheese, bananas, beer, wine, yeast, yogurt, and meat extracts containing tyramine, dopa, or serotonin. Patients who use MAO inhibitors should have their blood pressure monitored regularly.

Erythropoietin-a hormone that acts on bone marrow cells to stimulate red blood cell (RBC) production-causes increased blood pressure in one-third of patients with end-stage renal disease. Although the exact mechanism of action is unknown, erythropoietin may increase systemic vascular resistance by increasing blood viscosity and reversing hypoxic vasodilation.

Nonsteroidal anti-inflammatory drugs (NSAIDs) can increase blood pressure by blocking the production of prostaglandins in the kidneys, which leads to sodium and water retention. These drugs also antagonize the effects of some antihypertensive drugs, such as diuretics, by blocking sodium excretion. And NSAIDs cause vasoconstriction by affecting the renin-angiotensin-aldosterone system. African-Americans, diabetic patients, and the elderly are most vulnerable to the effects of NSAIDs. Keep in mind that the elderly commonly use NSAIDs for arthritis.

Cold remedies, nasal decongestants, and appetite suppressants also can cause hypertension. Generally, cold remedies and nasal decongestants are powerful vasoconstrictors that increase systolic and diastolic blood pressures. Appetite suppressants such as amphetamines, however, increase blood pressure by stimulating the CNS. Other types of appetite suppressants, such as dexfenfluramine, can cause primary pulmonary hypertension without affecting systemic blood pressure. Patients with advanced atherosclerosis, cardiovascular disease, or moderate to severe hypertension shouldn’t take appetite suppressants.