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Pushing questionably effective cures for hazily defined, chronic conditions has long been a signature sales strategy for the pharmaceutical industry. But the approval given by an FDA advisory committee on January 23rd to allow the prescription weight loss drug orlistat (Xenical) to be marketed over-the-counter brings the potential for the utilization of that tactic to a new level. As a prescription drug, orlistat combines minimal efficacy with not-insubstantial safety concerns. As an...
Pushing questionably effective cures for hazily defined, chronic conditions has long been a signature sales strategy for the pharmaceutical industry. But the approval given by an FDA advisory committee on January 23rd to allow the prescription weight loss drug orlistat (Xenical) to be marketed over-the-counter brings the potential for the utilization of that tactic to a new level. As a prescription drug, orlistat combines minimal efficacy with not-insubstantial safety concerns. As an over-the-counter medication, the potential exists for these safety concerns to multiply and cause serious harm.
Obesity in and of itself is a serious health problem. Obese persons put themselves at increased risk for type-2 diabetes, cardiovascular problems, and other health difficulties. However, obesity interacts with other risk factors, such as high blood pressure, family history, activity level, and smoking history, in a global assessment of general health. Thus, simply medicating obesity is unlikely to prevent the health problems associated with being overweight. Indeed, the professional product labeling for Xenical, the prescription version of orlistat, states that “the long-term effects of orlistat on morbidity or mortality [illness and death] associated with obesity have not been established.”
Yet drug-induced weight loss (often insignificant and/or unenduring though it may be) without accompanying lifestyle changes will be exactly the “impact” that the over-the-counter sale of orlistat will have. Glaxo Smith Kline, the company that will sell orlistat over the counter with the brand name Alli (pending FDA approval), argued that patients with obesity-related illnesses were not the intended consumers of the drug in its over-the-counter version, arguing that these conditions required the supervision of a physician. This meant, essentially, that anyone likely to suffer from the adverse health effects associated with obesity should not take this drug to lose weight unless they are under the supervision of a physician. The FDA disagreed with this model, calling it “difficult to imagine the proposed dichotomization of the target population into mildly-to-moderate overweight adults with and without weight-related co-morbidities [illnesses]...succeeding in the real world .”
Results from clinical trials support the FDA’s assesment. Of 247 subjects with conditions that would make the use of orlistat inappropriate, such as diabetes or hypertension, only 32% limited their use appropriately. Moreover, because of the mechanism that orlistat utilizes to assist in weight loss (preventing the absorption of fat from food as it is digested), users may suffer from a deficiency in certain fat-soluble vitamins. Clinical trials, however, showed that only 54% of users took the recommended vitamin supplementation according to the directions on the label.
On average, orlistat users lost about four to five pounds more than trial participants who were randomized to receive a placebo over a six month period. Data showed that as time progressed and participants returned to a diet with a normal intake of calories, subjects regained at least some of the weight that they had lost and the gap between the drug and the placebo narrowed. This means that as users of the drug will experience fewer of the benefits of the drug as time progresses while continuing to expose themselves to its adverse effects.
Adverse effects are not an uncommon problem with drugs designed to assist in weight loss. Two striking examples are the infamous “fen-phen” combination, which caused a serious heart condition, and sibutramine (Meridia), which causes serious elevations in heart rate and blood pressure. Over-the-counter diet drug phenylpropanolamine (PPA) caused hemorrhagic strokes, and the dietary supplement ephedra, used for weight loss, caused serious hypertension, heart attacks, and strokes. Of these, only sibutramine remains on the market, despite over 40 deaths attributable to the use of the drug.
Orlistat, too, causes substantial undesirable adverse effects that occur with disturbing regularity—about half of users experience some form. The most disturbing adverse effect are gastrointestinal—users report problems with abdominal discomfort, gas, and oily stools and loss of bowel control. But orlistat may also interact with other prescription drugs, most significantly the blood thinning drug warfarin. When taken under a doctor’s supervision, this interaction is less problematic, as it is easy for the prescribing physician to monitor a patient’s blood coagulation levels and prevent unnecessary bleeding episodes. But in an OTC setting, patients may not even tell their physicians that they are taking the drug, thus opening up the possibility that their blood will become too thin and put them at risk for severe bleeding episodes.
What, then, is the benefit of taking this drug? With the cost of a 30-day supply of OTC orlistat coming in at about $55, users will certainly pay dearly for every pound they shed. Is minimal, short-lived weight loss worth the price of potentially serious health problems? Is taking a pill without evidence that it can prevent the medical problems obesity brings with it worth the risk?
