Guest Author - Dr. Denise Howard
Hypertension or high blood pressure is the most common reason for office visits in non-pregnant adults. Approximately 30% of adults in the U.S. suffer from this problem and thus it represents the most common reason for chronic medication use. Overtime, different categories of medications have been developed to treat high blood pressure. This article will review the various categories.
All of the medications are equally effective with a response rate of 30-50%. There is, however, individual variability in response and tolerance of any given medication. In general, it is the reduction in blood pressure that decreases the risk of complications and not the actual medication itself. There are certain groups that tend to do better with one category versus the other. For instance, the elderly and blacks tend to respond better to thiazide diuretics or calcium channel blockers while younger people seem to do better with angiotensin converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARB).
Thiazide diuretics such as Hydrochlorothiazide and Chlorthalidone are typically used as an initial treatment. They work by decreasing the sodium reabsorption in the nephrons (absorption unit of the kidney). This increases the sodium in the urine, thereby increasing the water loss. How this lowers blood pressure isnít completely clear but a decrease in volume seems to contribute. The dose of the medication is 12.5 -100 mg daily. Chlorthalidone is preferred for many reasons including a lower effective dose. Side effects and complications include glucose intolerance, low potassium, increased uric acid, and low magnesium. As with most medications, using the lowest effective dose tend to minimize intolerable side effects.
Angiotensin converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARB) decrease or block the substance angiotensin, a vasoconstrictor which in turn raises the blood pressure. Commonly used ones include enalapril, lisinopril, captopril, valsartan, telmisartan, and losartan. There are many others. These medications are generally well tolerated but have the common side effects of cough and swelling. They can cause birth defects and should not be taken by pregnant women. This category of hypertensive medications is especially indicated when someone also has heart failure, a prior heart attack, chronic kidney disease and diabetes mellitus.
Calcium channel blockers (CCB) inhibit the calcium channels in cells. There are two types: the dihydropyridines which causes vasodilation but doesnít affect the vascular permeability and the non-dihydropyridines which also decreases vascular permeability and affect myocardial contractility and conduction. Commonly used medications in this category include diltiazem, verapamil, amlodipine and nifedipine. Common side effects include headache, dizziness, flushing and swelling. These are sometimes used to control heart arrhythmias.
Beta-blockers are rarely used as a first line agent in the treatment of high blood pressure. They work by blocking the effect of epinephrine thus slowing the heart rate and causing vasodilation. They tend to be useful in the management of arrhythmias, heart failure and the control of blood pressure after a heart attack. Common side effects include nausea, vomiting, diarrhea, dizziness, headache, and glucose intolerance.
In many cases a single agent isnít effect and the addition of a second drug maybe required to get ideal blood pressure control. In this scenario, drugs from different categories are used. Common combinations include diuretics with CCB or diuretics with ACE/ARB and even CCB with ACE/ARB. This is such a common practice that these combination medications have been manufactured and can be prescribed in a single pill.
If you have to take medications to control your blood pressure then I suggest you become knowledgeable about the medication. You should know the dosage, the brand and generic name, how the pill looks and expected side effects. Always take the medication as prescribed and follow up with your doctor if you have any problems. When the medication is issued by the pharmacy, always review the name and dosage to confirm it is what your doctor prescribed and if the appearance of the drug is different than expected then return to the pharmacists and ask questions. Make sure the answer is acceptable to you. Medications errors are common and you should make sure you or family members are receiving the right drugs.
I hope this article has provided you with information that will help you make wise choices, so you may:
Live healthy, live well and live long!