Weighing Drug Benefits Against Harms

Why do we take medicine? The most obvious answer is to feel better. If you have a headache, aspirin, acetaminophen (Tylenol) or ibuprofen (Advil) can often make it go away. Heartburn can be relieved with acid-suppressing drugs such as omeprazole (Prilosec) or ranitidine (Zantac).
Another reason to take a medication is to lower the likelihood of a serious complication in the future. Millions of people take blood pressure pills to reduce their chances of having a heart attack or a stroke.
Ultimately, though, one of the most compelling reasons to take drugs is to improve survival. A patient who has received a transplanted organ such as a kidney or lung must keep the body from rejecting this gift. Immune system-suppressing drugs such as cyclosporine or tacrolimus prolong life.
Determining whether the benefits of a medicine outweigh the risks is one of the most complicated decisions in modern medicine. Every drug has some side effects, though not every patient will experience them.
In some cases, a life-saving drug may cause such harm that a patient has to stop taking it. An antibiotic that staves off a dangerous infection may trigger a life-threatening allergic reaction. Penicillin is a well-known example.
Statins pose another dilemma. Drugs such as atorvastatin (Lipitor), lovastatin (Mevacor), rosuvastatin (Crestor) and simvastatin (Zocor) can prolong life in people with heart disease. What is not obvious, however, is whether these medications are beneficial for those who simply have high cholesterol without clear signs of heart problems. Two large analyses of statin studies concluded that statins don’t necessarily prolong the lives of healthy people (Archives of Internal Medicine, June 28, 2010; Cochrane Reviews, online, Jan. 19, 2011).
This news comes as a shock to many physicians who have been prescribing statins to lower cholesterol for years. They assumed that reducing cholesterol would pay dividends in improved survival. Some have been so dedicated to this concept that they insisted that patients continue taking the medicine despite debilitating muscle pain or weakness.
For physicians and patients to interpret research findings, they need a better understanding of the entire process behind clinical trials. One excellent resource is a book by Drs. Bengt and Curt Furberg entitled “Evaluating Clinical Research: All That Glitters Is Not Gold.”
One of the biggest challenges facing clinicians is to determine whether research findings are fair and balanced. Conflicts of interest can shape the way results are collected, analyzed and presented. Trials funded by the pharmaceutical industry are more likely to put a positive spin on the benefits of a drug and downplay its risks (BMJ, May 31, 2003).
Pooling the results from many studies in a meta-analysis is a popular way to assess the evidence for a medicine. A recent article in the Journal of the American Medical Association (March 9, 2011) found, however, that conflicts of interest are only rarely reported in such reviews.
Surveying the medical literature can be daunting. Patients must ask tough questions about actual benefits and potential harms for each prescription. Doctors and pharmacists have a responsibility to answer such requests as clearly and accurately as possible.