Friday, November 18, 2005

Popping Pills, Rx: Part IA

I take a lot of pills. Some of them are by prescription; some aren't. I have to rely on physicians to get the prescription medications. I don't have to take them, but I do. Not everything I do is based on self-experimentation. Some is based on authority. I am easily impressed with medical evidence, especially when there seems to be a large consensus among most of the medical community worldwide and that consensus seems to be supported by peer-reviewed clinical research not funded by those benefitting from sales of the the treatment.

Evidence-Based Medicine and Lipitor

My general practitioner/internist is a fairly straightforward practitioner of what is called "evidence-based" medicine. He doesn't waste a lot of time exhorting me to do something I'm not likely to do, like exercise more and eat less red meat. He has prescribed two medications that are supposed to be well supported by evidence. One is a statin, Lipitor, for controlling my cholesterol, especially LDL cholesterol. Or, at least, I think it's supposed to work just on LDL cholesterol. The other is a generic diuretic, triamterine, that is supposed to have the effect of lowering my blood pressure. He has prescribed these not because they have these specific effects, but because clinical evidence shows that people who take these medications live longer.
Interestingly, not very many medications have such a track record. One problem is that newer medications have not been around long enough to have a long-term track record. But, not all older medications have been studied either. Long-term studies are somewhat expensive, but, more significantly, data only becomes available close to the time when a medication's patent protection is close to expiration. Unless there is an unusual configuration of circumstances the makers of medications coming off patent have little incentive to fund expensive studies.

Much of the funding for such studies comes from governments, the governments of big, rich developed countries with lots of money that they and their citizens spend on medications. What country would be best fit that description, I wonder ?

Whether or not you are a U.S. taxpayer you get the benefit of the U.S.-funded study (Adult Treatment Panel III, "ATP III") located at: http://www.nhlbi.nih.gov/guidelines/cholesterol/atp3xsum.pdf. This study synthesized all of the research on cholesterol and cholesterol-lowering therapies and produced an evidence-based algorithm for treating adults.

One sidelight on statins is that an unknown enzyme in grapefruit juice seems to dramatically enhance their effectiveness. Unfortunately, because the enzyme has not been identified and its precise operation is unknown, no one is inclined to try to guess how to come up with the optimal grapefruit juice-statin combined therapy. Some pharmacies and doctors simply warn against drinking grapefruit juice while taking statins.

The Whole Enchilada

The entire list of pills is fairly daunting. Here are the prescribed ones. I intend to review each of these, examining the evidence supporting their use for me and for others. I intend thereafter to look at all of the over-the-counter drugs that I take and the evidence supporting their use.

Atorvastatin calcium (Lipitor) Prescribed Cholesterol lowering

Triamterine (generic) Prescribed Diuretic, blood-pressure lowering

Oxybutynin chloride (Ditropan XL) Prescribed Muscle relaxant, reduce over-active bladder symptoms

Atomoxetine HCl (Strattera) Prescribed Norepinephrine re-uptake inhibitor, ADHD

Amphetamine mixed salts (Adderall) Prescribed Stimulant, ADHD