The patients who come to your office to receive acupuncture and/or herbal therapy are often taking Western drugs. These may be over-the-counter (OTC) medications for pain control, allergies, colds, flu symptoms or a variety of other common problems.
Making a list of all the medications your patient takes on a daily basis is an important part of your careful assessment of that person prior to your own treatment. Having an adequate knowledge of what these drugs are and the effects they have will benefit your care of the patient and enhance the effectiveness of your treatments.
Last time, we looked at drugs that affected the nervous system (October 2009). In this article, I will cover drugs that exert their major effects on the cardiovascular system. The following discussion presupposes a basic understanding of the physiology of the cardiovascular system.
Hypertensive Drugs
Diuretics: The first line of defense in treating hypertension does not include prescribing a nervous system drug. Our first approach is lifestyle modifications, including stress reduction, weight control, exercise and emphasis on nurturing relationships. If drugs are needed because of a high-risk situation, the first class of drugs we use is the diuretics. These reduce blood pressure by decreasing blood volume through increased urine production. All these diuretics enhance water and sodium secretion. Their effect on other ions such as potassium depends on the drug. I will discuss diuretics here because they are so popular in treating hypertension although they do not affect the nervous system directly.
The leading diuretic is Diuril. It inhibits sodium, chloride and potassium reabsorption in the distal tubules of the kidney nephrons, bringing out water along with the excretion of these ions in the urine. Chlorthiazide is an ideal starting drug for hypertension or edema from heart failure. The main side effect is low serum potassium and calcium, and these must be closely monitored by blood tests, with supplemental potassium and calcium if not enough is taken in with food.
Potassium-sparing diuretics are now popular, including Aldactone and Dyrenium. More powerful diuretics are used in cases of severe pulmonary edema or fluid retention for other reasons (septic shock, for example). These include Lasix, Bumex and Edecrin. These are sometimes used in hypertensive crises along with alpha-blocking agents.
ACE Inhibitors: These highly popular drugs inhibit angiotensin-converting enzyme (ACE) in the lung which normally converts angiotensin I to the potent vasoconstrictor angiotensin II. The most commonly used agents include Capoten, Prinivil and Vasotec. Newer drugs in this class actually block the actions of angiotensin II at the vascular receptors. These angiotensin II antagonists include Cozaar and Diovan. There are very effective in controlling high blood pressure. Side effects are hypotension and dizziness.
Calcium-Channel Blockers: These drugs also have a role in treating hypertension, but their main usage is in treating heart disease. They block the release of calcium from the so-called channels (where it resides when it is inactive), which is an all-important step in smooth- and cardiac-muscle contraction. When these agents are administered, the heart becomes more relaxed, is less irritable and is less prone to angina in patients who have coronary artery insufficiency.
These drugs are also very useful in patients (often young people) who suffer from paroxysmal supraventricular tachycardia (PSVT). These episodes feel like a flip-flopping heart and they often last for a minute or two, then resolve. The drug of choice for treating PSVT is a calcium-channel blocker known as Isoptin. Other calcium channel blockers that are widely used include Cardizem and Procardia.
Nervous-System Blockers: Some of these agents, such as Dibenzyline and Minipress, operate by blocking alpha-1 receptors (these receptors cause vasoconstriction and raise the blood pressure when it is low due to shock conditions). Other medications for treating hypertension, such as Catapres and Aldomet, work by stimulating alpha-2 receptors (vasodilator receptors). In both cases, the blood pressure is lowered. Other agents, such as Ismelin and reserpine, block norepinephrine release from the nerve endings. These also lower the blood pressure.
Beta Blockers: Drugs that work as beta blockers also lower blood pressure by relaxing the heart and decreasing its force of contraction. Perhaps the best known of these is Inderal, a potent beta-1 and beta-2 blocker. It is contraindicated in patients with asthma because beta-2 blockage causes bronchoconstriction, especially in asthmatic patients. Other agents that are more specific beta-1 blockers are widely used to rest an overworked heart. Potent drugs in this category include Lopressor, Tenormin and Zebeta. In cases of hypertension, angina pectoris or actual myocardial infarction, these drugs can be very helpful if the patient does not have a tendency to go into heart failure. These decisions are best made by a cardiologist.
Direct Vasodilators: Hyperstat is a direct-acting vasodilator that is very quick and powerful in reducing blood pressure in a hypertensive crisis. Given IV, it blocks smooth-muscle constriction by decreasing calcium in ways that are not completely understood. It is used for short-term control of severe hypertension in a hospital setting, preferably in the ICU. Side effects include hypotension and shock, as well as hypoglycemia which may be difficult to reverse. This is an effective but quick-acting and dangerous drug, used in conditions where close monitoring is available.
Anti-angina Coronary Artery Dilators: Nitrogylcerin has been a mainstay in treating heart disease since the 1870s. It remains the most commonly used agent for angina; usually placed under the tongue for rapid onset of action. Causing its peak effect in one to two minutes, this lasts for about 30 minutes. Isordi is longer-acting and used to prevent attacks. Because it takes five minutes to become effective, it is not used for acute attacks. Side effects are few but include occasional hypotension in a few patients, with the possibility of rebound tachycardia because of falling blood pressure, which can make the angina worse.
Drugs for Cardiac Arrhythmias
Many cardiac arrhythmias are treated with calcium-channel blockers such as Covera. It is also used in treating atrial flutter, multifocal atrial tachycardia and atrial fibrillation, as well as less common arrhythmias. Beta blockers such as Inderal are also used, as are other specific agents for arrhythmias such as Quinidine and Novocain. Side effects are not uncommon, including nausea and vomiting and diarrhea. Procaine amide can cause a lupus-like syndrome in some individuals, which resolves when the drug is discontinued.
Drugs for Treating Heart Failure
Digitalis has been around for more than100 years. It is still the standard drug for heart failure. Similar to insulin, it comes in different forms in terms of onset of action and length of activity. The standard form, digoxin, is a true miracle drug for the heart. It increases the force of contraction of myocardial muscle cells by its effects on calcium and sodium, causing increased cardiac output in a weakened heart that is failing, resulting in decreasing heart size as it becomes more efficient, decreasing edema with decreased venous return. It thus increases renal perfusion and helps the kidneys get rid of extra fluid that has been building up in the body. A loading dose of digitalis is given followed by a smaller maintenance dose. When needed, there is nothing else quite like digitalis. It is much like a silver bullet
Side effects are common with this potent drug, including digitalis intoxication, with bradycardia and an irritable heart muscle that is prone to arrhythmias. Nausea and vomiting are also common with overdose, which often helps the patient keep the dose in check.
Beta blockers and ACE inhibitors have also been found to be helpful in treating patients with heart failure. Some patients have a variety of heart medications they are taking, carefully followed by a cardiologist or a competent internist.
Click here for previous articles by Bruce H. Robinson, MD, FACS, MSOM (Hon).