Drug Topics - November 10, 2008 - (Page 42)

Continuing Education COMPLICATIONS OF OBESITY index, is a simple measurement that can screen for overweight and obese patients.7 The BMI is calculated as body weight in kg divided by height in meters squared (kg/m2). BMI measurement is less accurate in patients if they have edema, are body builders, or have muscle wasting.4,5,8 The distribution of body fat is assessed through waist-to-hip ratios and waist circumference. Waist circumference provides supplementary information regarding risk until the BMI is above 35 kg/m2. Waist circumference may be a better estimation of adiposity in older patients and those ethnic populations that have normal body weight but unfavorable distribution of body fat. A waist-to-hip ratio of >0.9 in females and >1.0 in males confers higher cardiovascular disease risk. Patients should also be screened for medical conditions such as thyroid disease and Cushing’s disease, which may contribute to weight gain.5 TABLE 2 Obesity Co-morbid Conditions Cardiovascular disease* Hypertension* Dyslipidemia/ Hypercholesterolemia* Cholelithiasis Fertility complications/PCOS Cancers Hyperandrogenism Osteoarthritis Sleep apnea* Diabetes* Gout Stress incontinence Mental health disorders Phlebitis Drug Topics/Source: Ref. 5 *Highest risk PCOS: Polycystic ovarian syndrome Certain medications can cause weight gain and increase body fat, thereby making weight loss more difﬁcult (see Table 3). Several mechanisms alone or in combination are responsible for medication-induced weight gain. It can be due to an increase in appetite and therefore energy intake, as observed with antipsychotics and steroid hormones, or a decrease in energy expenditure, as is the case with betaadrenergic receptor antagonists. A decrease in energy, for example in patients with decreased glucosuria from diabetes therapy, may also play a role.3 Weight-loss therapy can be facilitated by decreasing the dose or substituting the medication with another drug that has less weight gain potential. Pharmacists are uniquely positioned to recommend substitutions, if possible, to reduce the incidence of weight gain. Weight-loss approaches The key approach to weight loss should center on the triad of dietary modiﬁcation, increased physical activity, and behavioral modiﬁcation. These lifestyle modiﬁcations should be considered for all patients with a BMI >25 kg/m2. 1,2,4-6 An obese patient with no concomitant risk factors or a patient with a BMI of ≥ 27 kg/m2 with concomitant risk fac- tors, including hypertension, dyslipidemia, coronary heart disease, type 2 diabetes, and sleep apnea, is considered at high risk and may be considered a candidate for pharmacotherapy if lifestyle modiﬁcations are unsuccessful.1,2,5,6 Pharmacotherapy should be considered only in the patient who has made lifestyle changes for a minimum of 6 months, yet has not achieved a weight loss of at least one pound per week. At the beginning of weight-loss therapy, the recommended initial weight-loss goal is a reduction of 10 percent of the baseline weight in the ﬁrst 6 months, at a rate of 1 to 2 pounds per week.5 A deﬁcit of 3,500 kcal is necessary to lose one pound of fat. Therefore, establishing an energy deﬁcit of 500 to 1,000 kcal/day translates into the recommended rate of weight loss. Weight-loss therapy is not appropriate in patients who are pregnant or lactating.5 Patients should be assessed and screened for uncontrolled psychiatric illnesses such as major depression or mood disorders, as these patients should also be excluded from therapy. In addition, those with active substance abuse should be referred for specialized care, and patients for whom caloric restriction might exacerbate their illness should not receive therapy. Dietary modiﬁcation is categorized by the nature of restriction: very low calorie diet (VLCD) of 400 to 800 kcal/day, low calorie diet (LCD) of 1,000 to 1,200 kcal/d, and meal replacement. VLCDs are primarily liquid or protein-sparing diets.5 Candidates are patients with a BMI >30 who are under medical supervision and who have failed at previous weight-loss attempts. While short-term results may be impressive, amounting to an average 26 kg weight loss at treatment end, results one year after treatment show that the VLCD is no more effective than an LCD. The LCD is more commonly prescribed by a physician and or dietitian aiming for a caloric deﬁcit of 500-1,000 kcal/d for the obese and a more modest 300-500 kcal/d for the overweight. These diets are moderate in fat intake (<30%), high in complex carbohydrates (50 to 60%), and moderate in protein (15 to 20%). Depending on the patient’s age, calcium supplementation is recommended at 1,000 to 1,500 mg/d, with 25 to 35g of ﬁber also recommended as a goal.9 Meal replacements are prepared meals of a milk shake, soup, or bar. Replacement meals usually have approximately 200 calories, 10% fat, 30% protein, and 50 to 60% carbohydrate. Meal replacements spare patients the need to make decisions about food selection and portion control; however, it is difﬁcult to adhere to this diet style long-term. Without modiﬁcation of poor eating habits, patients usually return to previous lifestyles and regain the weight. An initial weight-loss goal should be 0.5 lb to 1 lb/week or a 10% weight loss in six months.5 Patient motivation and commitment are critical for successful weight loss. Knowledge of patient readiness helps determine treatment strategies. Patients who have realistic goals and no life stressors, medical illness preventing weight loss, or psychiatric issues W W W.D R U GTO P I C S .C O M 42 DRUG TOPICS N OV. 10, 2008 http://WWW.DRUGTOPICS.COM

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Drug Topics - November 10, 2008 Contents Up Front Up Front in Depth Letters Rx Care Government Community Practice First Responders Clinical Practice Self-Care FDA Safety Page Weighing the Complications of Obesity New Products Viewpoint

Drug Topics - November 10, 2008

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