Can't tell which high blood pressure medicine is a diuretic, beta-blocker or ACE inhibitor? National Heart Centre Singapore Senior Pharmacist Connie Wong shares some tips.
HIGH BLOOD PRESSURE IS A LONG-TERM CONDITION
High blood pressure (hypertension) is a long-term medical condition in which one’s blood pressure remains higher than 140/90mmHg. Sustained high blood pressure can progressively damage the heart’s small and large blood vessels. This will affect the regulation of blood flow as well as other functions of blood vessels. Uncontrolled hypertension can cause serious complications including stroke, heart attack, kidney failure, and blindness.
High blood pressure can be managed with lifestyle modifications as well as medications. Common lifestyle changes include:
Exercising regularly
Stress management
Weight management
Reducing salt, sugar, fat and alcohol consumption
Quit smoking
HIGH BLOOD PRESSURE MEDICINE: HOW THEY WORK AND THEIR SIDE EFFECTS
If lifestyle modification measures do not work well enough, then medications could be prescribed to help control blood pressure. Medicines work in different ways to lower blood pressure, and the main categories of such medicines are: diuretics, beta-blockers, angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), calcium channel blockers, vasodilators, and alpha-blockers.
Medicines for lowering blood pressure can be used alone, or in combination (i.e. 2 or more medicines from different categories).
DIURETICS
This group of medication is widely known as “water pills”. They work by helping your kidneys get rid of salt and water via the urine. This reduces the liquid volume which the heart has to pump, which in turn reduces the blood pressure.
Side effects: Frequent urination, dizziness, and constipation. Potassium supplement may be prescribed to replace potassium loss from the urine.
BETA-BLOCKERS
Beta-blockers work by slowing down your heartbeat and reducing the force of the heart muscles, thereby reducing blood pressure. Patients who have history of asthma and chronic obstructive pulmonary disease (COPD) should take this medication with caution as it may aggravate their condition.
Side effects: slow heart beat, lightheadedness, constipation, and cold extremities.
ANGIOTENSIN CONVERTING ENZYME INHIBITORS (ACEIS)
ACE inhibitors is a type of high blood pressure medicine that helps prevent an enzyme in your body from producing angiotensin II. Angiotensin II is a potent vasoconstrictor which makes your blood vessels smaller and increases blood pressure. ACE inhibitors will help reduce the narrowing of your blood vessels, thus decreasing your blood pressure. ACE inhibitors are particularly beneficial for patients with diabetes or kidney problems.
Side effects: Dry cough is the most common side effect. Other known side effects include dizziness and headache.
ANGIOTENSIN RECEPTOR BLOCKERS (ARBS)
ARBs block the action of a hormone, called angiotensin II, which constricts blood vessels. This blocking effect relaxes your blood vessels and lowers your blood pressure, making it easier for your heart to pump blood. Patients will be prescribed with ARBs when they are intolerant to ACE inhibitors.
Side effects: Fewer with ARBs, but possible side effects include headache, dizziness and lightheadedness.
CALCIUM CHANNEL BLOCKERS
This agent prevents calcium from entering cells of the heart and blood vessel walls, producing vasodilatation, resulting in lower blood pressure. The calcium involved is different to the ones responsible in keeping your bones strong.
Side effects: May include headache, constipation, rapid heartbeat, shortness of breath and possibly swelling at the feet and lower legs.
VASODILATORS
Vasodilators is a type of blood pressure medicine that work directly on the muscles in the walls of your arteries. It prevents the muscles from tightening and the walls from narrowing. This effect helps in lowering your blood pressure.
Side effects: May include fluid retention, headache, dizziness and rapid heartbeat.
ALPHA-BLOCKERS
Alpha blockers work by keeping the hormone noradrenaline from tightening the muscles of smaller arteries and veins. Hence, the blood vessels remain open and relaxed. This improves blood flow and lowers blood pressure. Alpha-blockers can help improve urine flow in older men with prostate problems.
Side effects: May include hypotension, headache, pounding heartbeat and nausea.
High blood pressure is a challenging public health problem. If it is not well managed, more serious complications such as atherosclerosis, stroke and heart attack will arise. Hence, with active public health prevention, awareness education, lifestyle modifications and medication compliance, one can potentially decrease both hypertensive prevalence and its complication risks.
Ref: Q15
