Wednesday, February 29, 2012

Drugs, Pharmacology, and Humans, Part I

     Many patients do not fully understand the purpose of medication, and fall into the false belief that the less medicine they take, the less sick they are. While it certainly is  true that the patient who takes no medicine is fundamentally healthier than the patient who takes medicine, in some cases the patient who takes medicine (e.g. statins to lower cholesterol) may end up being healthier (have less chance of a heart attack) than the patient who takes none. The purpose of most medications  is  to try to return the patient to the "normal" state, i.e. one in which a doctor's attention is not needed. I will discuss several classes of medicines in this blog.

     I first want to emphasize the fact that not all side-effects are dose-dependent. Therefore any medicine you take can cause side effects without benefits if the dose is too low. Thus unless you take the full dose of the medicine as prescribed by your doctor, you are exposing yourself to possible side effects without getting the full benefit of the medicine. I have seen patients try to self-taper asthma, diabetes and blood pressure medicines, always without any benefit to them.

     Generics usually work as well as brand-name medicines, with the notable exception of any medicine that acts on the CNS system---i.e. the brain (and the spinal cord). This is because there is a natural blood-brain barrier that prevents many drugs from diffusing from the blood stream across the capillary wall and into the brain cells. Most notably, I have found that generic Prozac, generic Wellbutrin, and especially generic Ativan do not always have the same effect as does the brand name drug.

     Many patients ask "How do I know that we will not find out 20 years down the road that the medicine you are prescribing will not be found to have dangerous side effects?" Of course they never ask this question about the sweetener in diet sodas, the chemicals in herb tea, the various vitamins and pills they buy in a health food store, etc. In fact virtually no food that we ingest has been examined for long-term effects with two notable exceptions: alcohol in any form can reduce your risk of a heart attack, and although reducing the amount of salt in your daily diet can lower your blood pressure, this dietary intervention has  NOT been shown to  reduce your risk of a heart attack or to  increase your life span.

     Blood pressure medicine: Like diabetes, high blood pressure can be a "silent killer". The most destructive result of untreated hypertension is a stroke, which often leads to either death or permanent paralysis of a limb or one side of the body, along with the loss of speech, etc. And we know from clinical trials that treating high blood pressure with drugs can greatly lower your risk of having a stroke. We have no way of predicting which  bodily organ the high blood pressure will affect. If untreated it can cause ministrokes, heart failure, kidney failure, and /or damage to your vision. Just as a low salt diet can lower pressure, a diuretic ("water pill") is and should generally be the first line of treatment for this disease. A diuretic increases the amount of salt excreted in your urine, and thereby lowers the total amount of salt in your body. If it is not the first medicine you are given, it should be the second, as an added treatment, because lowering the amount of salt in your body potentiates the anti-hypertensive effect of all other classes of blood pressure-lowering medicines. The other medicines used to treat hypertension are beta-blockers, calcium channel blockers, ACE inhibitors, ARB's, other vasodilators, and anti-renin drugs.

     The choice of a second anti-hypertensive drug if a diuretic alone does not achieve a low enough blood pressure depends on the type of individual as well as his/her underlying medical conditions and medications that are already being taken. Male, female, black, white, old, young, heart failure, asthma, COPD, GERD, smoker, chronic edema, are all some of the factors that will affect the choice of a second anti-hypertensive. I would also like to state that for reasons that we do not understand, black males are the most likely to suffer a stroke from untreated hypertension, and therefore blood pressure must be treated aggressively and closely monitored in this group.

3 comments:

  1. Added note: Patients should NEVER make drastic life decisions (engagments, divorce, marriage, have a child, etc.) while they are changing any psychiatric medicines they are taking, and for one month after the change.

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  2. Great tips, cheers to the article author. Its understandable to me now, the effectiveness and importance is mind-boggling. Thank you once again and good luck!

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  3. The FDA just took the generic form of long-acting Wellbutrin, 300mg XL, off the market because it was not lasting 24 hours in patients.

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