Prescription Drug Use: New Podcast Dispels Many Myths

One of the many information sources used in preparing our articles is Therapeutics Initiative, which publishes a free online newsletter. This project was established in 1994 by the Department of Pharmacology and Therapeutics in cooperation with the Department of Family Practice at the University of British Columbia, Vancouver. According to this Web site, its purpose is “to provide physicians and pharmacists with up to date, evidence-based, practical information on rational drug therapy. The Initiative is an independent organization, which is at arms length from government, pharmaceutical industry and other vested interest groups.”

Last Spring, two professors affiliated with this program began podcasting on the Therapeutics Initiative Web site (www.ti.ubc.ca). One of them, James McCormack, Pharm.D, who is with UBC’s Faculty of Pharmaceutical Sciences, is interviewed by Maryann Napoli, Center for Medical Consumers.

MN: Your podcasts are unique. There is no show that I know of in the mainstream U.S. media that draws upon the evidence the way you do to dispel myths about drug treatment. You are addressing primary care physicians, but there is much to be learned by anyone who takes drugs.

JM: Thank you. My co-host, Dr. Mike Allan, who is a great family doc at the University of Alberta, Edmonton, and I have been doing these podcasts primarily because they are fun to do and hopefully the information is useful to the listeners.

MN: I’m going to touch on different subjects to give my readers an idea of the range of topics you address in your shows. I’ll start with dose. Whether you’re talking about drugs for high blood pressure or antibiotics for sinusitis or strep throat, you make the point that drug doses are often set arbitrarily and the high-end doses are usually too high for most people. Is there general advice you can give here?

JM: If the condition [for which you will be taking the drug] will kill you tomorrow, take a big dose just in case. If the condition is not life-threatening or urgent, then there is absolutely no reason to start with the dose that is typically recommended. Typically, those are the doses that have been shown to work in most people.

MN: Because there’s a range of responses.

JM: Yes. It has been established that the initially recommended doses, especially for new drugs are, on average, too high for many people. When you look at the dose-response curve from trials, you see that many people respond to lower doses, but there is absolutely no way you can predict in advance who will respond to what dose. If there’s no hurry, and given that many conditions get better on their own, start with a small dose. Typically, ¼ of the recommended dose is where to start.

MN: Now for the duration of drug treatment. In one show, you said something that sounded like heresy because the public is told to complete the 10- or 14-day antibiotics regimen or something horrible will happen. Yet you said that for respiratory infections like sinusitis, bronchitis, and even community-acquired pneumonia [as opposed to hospital-acquired pneumonia], people can stop taking their antibiotics when they feel better and have no fever for three days. Typically that would be a 5-day course for many people, but you also said it depends on how quickly they respond.

JM: Three-day courses of antibiotics have been shown in studies to be effective for bladder infections and there is even a study of 3-day treatment for pneumonia. For almost all upper respiratory tract infections the most you need is five days. The key is if you are not improving after 2-3 days, you need to be reassessed by the prescribing physician. Interestingly, there was no evidence to support that 10- to 14-day recommendation in the first place. However, there are a few infections that require taking antibiotics for a longer time—bone infections, prostate infections, cardiac infections, but for most non-life-threatening infections, shorter [until you have felt better for 3 days] is usually just as good.

MN: You often joke that “we [health care practitioners] don’t know what we’re doing.” You said it recently in one of your shows about upper respiratory illnesses. Why is it that doctors don’t know the correct dose or type of antibiotic to use for these common conditions?

JM: It ‘s not so much we don’t know what we are doing, but we don’t always have studies that look at the answers to the important day-to-day clinical questions. I want to know what is the best drug and how long must it be taken. Many of the antibiotics in use today came on the market way before we did lots of trials. Unfortunately, the research done by drug companies often doesn’t answer the questions we need to know the answers to. We do what we were taught and don’t question whether it’s the best way to do something. How can I predict whether you would need 10 or 5 days of an antibiotic?

MN: People on anti-hypertension drugs might be surprised to learn from your show that drugs reduce the risk of heart attack, cardiac death, stroke by only 1-2% over five years. You said that there is uncertainty about whether this is due to the mechanism of the drugs or the lowered blood pressure.

JM: We don’t know exactly, but we’re pretty convinced that some of the effect is from blood pressure lowering. But there are a number of studies that show drugs that equally lower blood pressure do not produce equal reductions in the rates of heart disease. For instance, atenolol* is a highly prescribed drug that lowers blood pressure. However in clinical trials lasting 5 years, the people taking atenolol had the same number of heart attacks or strokes as those taking a placebo. That tells you something else is going on. Either blood pressure reduction is not the major reason for that 1-2% benefit from anti-hypertensive drugs, or any potential benefit from atenolol’s blood pressure lowering effect was offset by the inherent toxicity of atenolol. Even though we don’t know exactly what is going on, we do know that patients who take atenolol for 5 years are not reducing their chance of heart disease, which is the only reason to take drugs for high blood pressure.

MN: Given your general advice about starting with a low drug dose and the lack of certainty that anti-hypertensives work by lowering blood pressure or some other mechanism, why is dose a guide here?

JM: Because the major reason to start with a low dose is to reduce side effects and the second is to reduce cost. You’re right, it’s a catch-22 situation here. The drugs are given to lower blood pressure. We know very well that lower doses typically produce most of the blood-pressure lowering effects and increasing doses rarely adds much more benefit. We also know from studies that even if you did nothing, many patients’ blood pressure would go down over time.

MN: Blood pressure goes down without drugs?

JM: We know from any anti-hypertensive trials about 50% of the people on placebo will have normal blood pressure within a year. So take low doses, see the doctor periodically to have blood pressure measured and every year or so, in conjunction with your physician, start slowly cutting back on your medications to see if you still need them. Don’t lose sleep over your blood pressure. It’s inappropriate to scare people by telling them it is a silent killer. Blood pressure of, say, 160/100 increases your risk of cardiovascular disease by 2-3 % over 5 years compared to someone who has a blood pressure of say 140/85. That’s what you need to know.

MN: Why give anti-hypertensive drugs if untreated blood pressure goes down in so many people?

JM: The 1-2% reduction in cardiovascular disease over five years we mentioned earlier. Hopefully, there will be more over a lifetime. Many people see this as an important difference [over a placebo—that is, no treatment]. However, and most importantly, if these drugs cause any side effects you are on the wrong drug.

MN: I liked something you said about osteoporosis: “If you’re not prepared to take one of the bone drugs like Fosamax or raloxifene, then don’t have a bone density test. That makes so much sense, but I doubt many women have had this explained.

JM: It’s in the Physician’s Guide to Prevention and Treatment of Osteoporosis. National Osteoporosis Foundation; 2000. “Utilizing any procedure to measure bone density is not indicated unless the results will influence the patient’s treatment decision,” which is in agreement with the U.S. Preventive Service Task Force recommendations for postmenopausal women.

MN: In describing studies, you often show how small the benefit of drug treatment can be, demonstrating that most people with self-limiting conditions get better in time without treatment. For example, you cite a Cochrane Review of the best trials involving the use of steroid intra-nasal spray for sinusitis, which made 73% feel better, compared with 66% of those on placebo.

JM: People don’t know the questions they should ask about drugs. Most important is: What will happen if I do nothing? What’s my ballpark chance of death, heart attack, stroke, fracture, symptoms etc) over, say, the next 5-10 years if I don’t take drugs. Then get the doctor to give a rough idea of how much the drugs will reduce that chance. Then get a ballpark estimate about your chance of having severe side effects.

Based on that information, you decide whether or not to take the drug and whatever decision you make, your doctor should support that decision.

*Atenolol has been sold under brand names like Tenoretic, Tenormin and Apo-Atenolol for nearly 35 years. A 2004 analysis of four randomized trials, published in the British journal Lancet, challenged atenolol’s safety and efficacy.

Maryann Napoli, Center for Medical Consumers ©

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