Drug Therapy For Weight Management
Antidepressents: Effects of Selected Medications on Weight
(fluoxetine [Prozac, Sarafem]) weight loss with short-term use & weight gain as tricyclic anti-depressants (TCAs) amitriptyline (Elavil). TCAs, Mirtazapine (Remeron) & phenelzine (Nardil) have long been associated w/ excessive appetite & weight gain. Efects of bupropion (Well-butrin & Zyban) on weight are unclear. Gain was reported when used as smoking deterrent, but both gain & loss when used as an antidepressant. Anorexia & weight loss occurred at a higher than increased appetite and weight gain.
A patient began taking phentermine 3 weeks ago and has presented for her biweekly follow-up appointment at the clinic. If the patient weighed 340 pounds at her last visit, an appropriate weight at his visit would be. A. 337 pounds B. 333 pounds C. 330 pounds D. 339 pounds (NCLEX THE POINT)
ANSWER: A → a recommended rate of weight loss while taking pherntermine is 1 to 2 pounds weekly.
Overweight and obesity involve many factors, including which of the following? Select all that apply. A. Environmental factors B. Genetic factors C. Physiologic factors D. Psychosocial factors (NCLEX THE POINT)
ANSWER: A, B, C, & D → The etiology of excessive weight is thought to involve complex and often overlapping interactions among physiologic, genetic, environmental, psychosocial, and other factors.
Being overweight or obese is a widespread problem throughout the United States and is considered a major public health problem. What is the basic cause of being overweight or obese? A. Excessive amounts of carbohydrates B. Excessive amounts of nutrients C. Excessive amounts of fats D. Excessive amounts of proteins (NCLEX THE POINT)
ANSWER: B → Excessive amounts of proteins, carbohydrates, and fats are converted to fat and stored in the body, resulting in overweight and obesity.
Phentermine aids weight loss by A. Decreasing appetite B. Increasing satiety and feelings of fullness C. Increasing metabolism D. Decreasing absorption of dietary fat (NCLEX SUCCESS)
ANSWER: B → Phentermine is an appetite suppressant with effects thought to be due to direct stimulation of the satiety center in the hypothalamic and limbic region.
Drug therapy for obesity has a problematic history due to adverse effects. Which medication is approved for long-term use? A. Guarana B. Orlistat C. Adipex-P D. None of these (NCLEX THE POINT)
ANSWER: B→ The lipase inhibitor orlistat is commonly used and is the only weight-loss drug approved for long-term use.
Phentermine (Adipex-P, Ionamin, Pro-Fast): Assessing for Adverse Effects
Assess for elevated BP, increased nervousness, hyperactivity, or symptoms of dry mouth or constipation.
Phentermine (Adipex-P, Ionamin, Pro-Fast): Assessing for Therapeutic Effects
Assess for recommended rate of weight loss (1-2 pounds weekly), minimal adverse effects, & use w/ healthy diet & exercise routine.
Orlistat (Xenical, Alli): Assessing for Adverse Effects
Assess signs of common adverse GI effects (e.g., diarrhea, flatulence) & reduced concentrations of fat-soluble vitamins. To minimize effects, encourage to distribute fat calories over 3 main meals & avoid high-fat meals.
Antihypertensives: Effects of Selected Medications on Weight
Beta Blockers can cause fatigue & decrease exercise tolerance & metabolic rate, all contribute to weight gain. Alpha-blockers may also cause weight gain, but at a low incidence.
Orlistat (Xenical, Alli): Action
Binds to gastric & pancreatic lipases in the GI tract, & it can prevent the absorption of 30% of ingested fat. Triglycerides, cholesterol, & fat-soluble vitamins from fat-containing foods pass through intestines unchanged & are not absorbed. Increasing the dose does not increase the percentage.
Dyslipidemias: Health Risks of Obesity
Changes lipid metabolism (e.g., increased triglycerides & LDL; decreased HDL) that increase risks of cardiovascular disease & other health problems.
Sleep Apnea: Health Risks of Obesity
Commonly occurs in obese persons. Due to enlargement of soft tissue in the upper airways that leads to collapse of the upper airways w/ inspiration during sleep. o Obstructed breathing leads to apnea w/ hypoxemia, hypercarbia, & a stress response. Associated w/ increased risks of HTN, possible right HF, & sudden death. Weight loss leads to improvement in sleep apnea.
Other Factors
Diseases are rarely a cause. Numerous disease processes may limit ability to engage in calorie-burning activity. Also, many prescription medications cause weight gain.
AntihistaminesHistamine1 (H1) antagonists: Effects of Selected Medications on Weight
(e.g., diphenhydramine, loratadine) increase appetite & cause weight gain.
Antipsychotics: Effects of Selected Medications on Weight
Mechanism unknown, weight gain has been associated w/ anti-histaminic effects, anticholinergic effects, & blockade of serotonin receptors. Clozapine & olanzapine cause weight gain. Compared with clozapine and olanzapine, risperidone causes less weight gain, & quetiapine and ziprasidone cause the least weight gain. Weight gain may lead to noncompliance with drug therapy. The extent to which these effects are related to weight gain is unknown.
Cholesterol-Lowering Agents: Effects of Selected Medications on Weight
Mechanisms & extent are unknown.
Antiepileptic Drugs (AED):Effects of Selected Medications on Weight
Mechanisms by which the drugs promote weight gain are unclear but may involve stimulation of appetite &/or a slowed metabolic rate.
Phentermine (Adipex-P, Ionamin, Pro-Fast): Contraindications
Moderate to severe HTN, cardiovascular disease, & a history of drug abuse. Caution is warranted in anxiety or agitation because the drug may have CNS-stimulating effects.
Orlistat (Xenical, Alli): Assessing for Therapeutic Effects
Monitor weight loss & BMI. Most weight loss occurs in first 6 months of therapy, but as patients continue to take orlistat, they can maintain the weight reduction. The metabolic improvements of weight loss are very beneficial for people w/ obesity-related health problems (diabetes, dyslipidemia, HTN, & metabolic syndrome).
Genetic Factors
Most cases of obesity due mainly to combination of genetic susceptibility & environmental conditions.
Orlistat (Xenical, Alli): Administering Medications
Necessary to take orlistat 3x a day w/ meals. Because the drug prevents absorption of the fat-soluble vitamins A, D, E, & K, people who take it should also take a multivitamin 2 hours before/after orlistat.
Environmental Factors
o Ready availability & relatively low cost of foods, large portion sizes & high-calorie foods. o Usual activities of daily living for many people: work-related activities, require relatively little energy expenditure. Few Americans are thought to exercise in the optimal frequency, intensity, or duration to maintain health & prevent excessive weight gain. o For both adults & children, increased time watching TV, playing video/computer games, & working on computers
Overview of Weight Management
• Body mass index (BMI) reflects weight in relation to height. • Overweight: BMI of 25 to 29.9 kg/m2. • Obesity: BMI of 30 or more kg/m2. • Desirable BMI range: 18.5 to 24.9 kg/m2 - Below 18.5 = underweight & greater then 25 = excessive weight • Large waist circumference, greater than 35 inches (women), greater than 40 inches (men), is another risk factor for overweight & obesity.
Pathophysiology
Results from consistent ingestion of more calories than are used for energy, & it substantially increases risks of developing numerous health problems. Most obesity-related disorders are attributed mainly to the multiple metabolic abnormalities associated w/ obesity. Abdominal fat out of proportion to total body fat (visceral or central obesity), which often occurs in men & postmenopausal women, is considered a greater risk factor for disease & death than lower body obesity. Obesity considered a chronic disease in its own right.
Etiology
o Carbohydrates, proteins, & fats required for human nutrition. Either deficiencies or excesses impair health, cause illness, and interfere with recovery from illness or injury. o Carbohydrates and fats serve as sources of energy for cellular metabolism, & proteins are basic structural & functional components of all body cells & tissues. o Energy is measured in kilocalories per gram of food oxidized in the body. Carbohydrates & proteins supply 4 kcal/g. Fats supply 9 kcal/g. Excessive amounts of any nutrient are converted to fat & stored in the body, resulting in excess weight & obesity. o More likely to occur in women, ethnic groups, & people of lower socioeconomic status. Generally, more women than men are obese, whereas more men than women are over-weight. African American women & Mexican American men & women have the highest rates of overweight & obesity in the US. o Etiology thought to involve complex & often overlapping interactions among physiologic, genetic, environmental, psychosocial, & other factors.
Physiologic Factors
o Increased weight related to an energy imbalance in which energy intake (food/calorie consumption) exceeds energy expenditure. Total energy expenditure represents the energy expended at rest (i.e., the basal or resting metabolic rate), during physical activity, & during food consumption. o When eating, about 10% of energy content is expended in digestion, absorption, & metabolism of nutrients. Foods that contain carbohydrates & proteins stimulate energy expenditure; high-fat foods have little stimulatory effect. The energy required to metabolize & to use food reaches a maximum level about 1 hour after the food is ingested. o Excessive weight can result from eating more calories, exercising less, or both. Consuming extra 500 calories a day for a week results in 3500 excess calories/one pound of fat. Excess calories are converted to triglycerides & stored in fat cells. With continued intake of excessive calories, fat cells increase in both size & number.
Orlistat (Xenical, Alli): Use
o Intended for people who are clinically obese, not for those who want to lose a few pounds. It is necessary to decrease consumption of high-fat foods because total caloric intake is a major determinant of weight, & adverse effects (e.g., diarrhea; fatty, malodorous stools) worsen / consumption of a large amount of fat. o The effects of long-term orlistat use are unknown. Clinical trials found that orlistat results in reduced severity & improved management of other health problems associated w/ obesity, such as diabetes & HTN. Studies have shown that the addition of orlistat therapy to diet & other lifestyle changes produces greater weight loss than a placebo. In some patients w/ impaired glucose tolerance, weight loss w/ orlistat & lifestyle changes prevents or delays the occurrence of diabetes m. After the medication is stopped, most patients regain weight. o FDA has approved use in children aged 12+ & considers the drug to be safe & effective for weight reduction in overweight adolescents o Use in older adults: Recommendations advise conservative use & lower dosages, because older adults often have decreased renal, cardiac, & hepatic function.
Psychosocial Factors
o May be either a cause or an effect of obesity. o Depression and/or abuse may play a role; often report symptoms of depression, & some overeat & gain weight in depressive episodes. It may be that obesity and depression commonly occur together and reinforce each other.
Phentermine (Adipex-P, Ionamin, Pro-Fast): Adverse Effects
o Most common: nervousness, hyperactivity, dry mouth, constipation, & HTN. Impotence, insomnia, and unpleasant taste may also occur. o Tolerance to the drug usually occurs w/in 4 to 6 weeks & an indication for discontinuing drug. Continued administration or use of large doses does not maintain appetite-suppressant effects. Instead, it increases the incidence of adverse effects. o QSEN: The nurse should emphasize to patients that phetermine may be habit-forming & should be used only as prescribed. There may be an increased risk of drowsiness, so people who take phentermine should not drive a car or operate heavy machinery until they know how the drug affects them.
Drug Therapy
o NHLBI recommend drug therapy w/ BMI of 30+ & health problems that are likely to improve w/ weight loss. Emphasize that therapy should be used as part of weight management program that also includes a sensible diet, physical activity, & behavioral modification. NHLBI clinical guidelines focus on identification, evaluation, & treatment. Emphasize that drug therapy should be used to decrease medical risk & improve health rather than weight loss. Drug therapy has a problematic history, mainly because of serious adverse effects & rapid weight regain stopped. o The FDA took some drugs & a component of many over-the-counter and herbal weight loss products (ephedra & ma huang) off the market because of adverse effects. Two classes of weight loss agents, noradrenergic agents & lipase inhibitor, are currently available by prescription. Of the adrenergic anorexiant drugs, only phentermine is commonly used. Lipase inhibitor orlistat is also commonly used & the only weight loss drug approved for long-term use.
Orlistat (Xenical, Alli): Pharmacokinetics
o Not absorbed systemically; works in GI tract. Primary metabolite half-life: 3 hrs; second metabolite half-life: 13.5 hrs. o Excreted in feces, 83% as unchanged drug.
Cardiovascular Disease: Health Risks of Obesity
o Obesity during adolescence is associated w/ higher rates & greater severity of cardiovascular disease as adults. Increases risks of HTN, insulin resistance, low HDL cholesterol, & hypertriglyceridemia. o An independent risk factor for cardiovascular disorders, & central obesity may be more important than BMI as a risk factor for death from cardiovascular disease. The increased mortality rate is seen even w/ modest excess body weight. HTN, dyslipidemia, insulin resistance, & glucose intolerance are known cardiac risk factors in obese people. o HTN often occurs in obese people & plays a role in the increased incidence of cardiovascular disease & stroke observed in patients w/ obesity. o Metabolic abnormalities that occur w/ obesity & type 2 diabetes aggravate HTN & increase cardiovascular risks. Combination of obesity & HTN is associated w/ cardiac changes that lead to heart failure more rapidly. Weight loss of as little as 4.5 kg (10 pounds) can decrease BP & cardiovascular risk in many people w/ obesity & hypertension.
Metabolic Syndrome: Health Risks of Obesity
A group of risk factors & chronic conditions that occur together & increase risks of diabetes m., cardiovascular disease, & death. o Highly prevalent in US. Characteristics include many of the health problems associated w/ obesity. More specifically, it includes 3+ of the following: - Central obesity (waist circumference + 40 inches for men & + 35 inches for women) - Serum triglycerides of 150 mg/dL or more - HDL cholesterol below 40 mg/dL in men & below 50 mg/dL in women - Blood pressure of 135/85 mm Hg or higher - Serum glucose of 110 mg/dL or higher
Your patient, a 17-year-old girl, has several risk factors for obesity, one of which is a large waist circumference. What waist measurement is a high risk factor for overweight and obesity in women? A. Above 35 inches B. Above 32 inches C. None of the above D. Above 38 inches (NCLEX THE POINT)
ANSWER: A → A large waist circumference (above 35 inches for women, above 40 inches for men) is a risk factor for overweight and obesity.
Excessive caloric intake results in increased body weight. How many excess calories equal 1 pound of fat? A. 3500 calories B. 4000 calories C. 2500 calories D. 3000 calories (NCLEX THE POINT)
ANSWER: A → Consuming an extra 500 calories a week results in 3500 excess calories or 1 pound of fat.
To decrease diarrhea with orlistat (Xenical), it is important to instruct a patient to A. Avoid large amounts of fatty foods B. Drink eight glasses of water daily C. Avoid caffeine-containing beverages D. Increase physical activity (NCLEX SUCCESS)
ANSWER: A → Encourage people to distribute fat calories over the three main meals and to avoid high-fat meals to minimize the gastrointestinal effects of abdominal pain, oily spotting, fecal urgency and incontinence, flatulence with discharge, fatty stools, and diarrhea.
A patient who is taking orlistat has reported to her nurse that her stool leave an oily film on her toilet bowl since she began taking the drug. What teaching point should the nurse convey to the patient? A. Oily stools are a common adverse effect of orlistat. B. The patient will likely require a higher dose of orlistat C. The patient should temporarily eliminate fats from her diet. D. Oily stools are a sign of gallbladder disease, and the drug will likely be discontinued. (NCLEX THE POINT
ANSWER: A → Fatty stools are a common adverse effect of orlistat and are directly related to the drug's mechanism of action. This is not indicative of gallbladder disease. The patient should likely limit her fat intake, but it is not necessary to completely eliminate them from the diet.
Mr. Johnson, a 42-year-old architect, is more than 40 pounds overweight, and he has a 14-year history of type 1 diabetes mellitus. He is placed on phentermine and has been taking it for the last 8 weeks. His latest glycosylated (A1c) hemoglobin concentrations have risen to 9% despite that he has maintained a healthy diet and routine exercise program. Phentermine may cause an elevation of A1c levels by: A. Producing stimulant effects to the sympathetic nervous system B. Decreasing the level of fat-soluble vitamins C. Decreasing metabolism to the pancreas D. Increasing the absorption of dietary fat (NCLEX SUCCESS)
ANSWER: A → People with diabetes mellitus may require increased doses of insulin while taking phentermine because the drug produces effects similar to those caused by stimulating the sympathetic nervous system.
Calorie consumption is necessary to provide energy to support bodily function during rest, physical activity, and food consumption. When is the maximum energy to metabolize and use food required? A. 1 hour after food is ingested B. 2 hours after food is ingested C. Maximum energy is needed until stomach is emptied D. Upon ingestion (NCLEX THE POINT)
ANSWER: A → The energy is metabolized and use food reaches a maximum level about 1 hour after food is ingested.
An obese patient is scheduled to begin treatment with phentermine, and the nurse is conducting the necessary health education. When describing the possible adverse effects of phentermine, the nurse should highlight which f the following? A. Nervousness and agitation B. Nausea and vomiting C. Drowsiness and lethargy D. Increased flatulence and diarrhea (NCLEX THE POINT)
ANSWER: A → The most commonly reported adverse effects with phentermine are nervousness, hyperactivity, dry mouth, constipation, and hypertension. Nausea, drowsiness, and GI effects are atypical.
An obese patient with type 1 diabetes controls her blood glucose levels by adhering to her insulin regimen. Which of the following principles should be taking into account when planning a course of phentermine to treat her obesity? A. The patient may require a higher-than-normal dose of phentermine. B. The patient should increase her protein intake for the duration of treatment. C. The patient may require increased doses of insulin. D. The patient should supplement her insulin with oral antihyperglycemics. (NCLEX THE POINT)
ANSWER: C → It is important to note that people with diabetes mellitus may require increased doses of insulin while taking phentermine because the drug effects similar to those caused by stimulating the sympathetic nervous system.
In counseling a patient about weight loss diets, the nurse knows that a recommended low-calorie or reduced- calorie diet A. Provides about 500 to 800 kcal/d B. Reduces daily intake to about 1800 kcal/d C. Is required for weight loss D. Focuses on high-fat, high-carbohydrate foods (NCLEX SUCCESS)
ANSWER: C → Low-calorie diets provide 1200 to 1600 kcal/d. The usual recommendation is to reduce caloric intake by 500 to 1000 cal daily, to allow weight loss of 1 to 2 pounds weekly. This rate of loss is likely to be more successful in terms of weight loss, and continuing a reduced-calorie diet promotes weight maintenance rather than weight regain.
Drug therapy for weight management may be prescribed for patients with which of the following? A. A BMI of 22 kg/m2 and a desire to lose 10 pounds B. A BMI of 24.5 kg/m2 and physically fit C. A BMI of 30 kg/m2 or more with weight-related health problems D. A BMI of 25 to 29 kg/m2 and healthy (NCLEX SUCCESS)
ANSWER: C → The National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health and most other organizations generally recommend reserving drug therapy for those with a body mass index, or BMI, of 30 kg/m2 or greater and health problems (e.g., hyperten- sion, dyslipidemia, coronary heart disease, type 2 diabetes, sleep apnea) that are likely to improve with weight loss. Drug therapy should be considered in conjunction with healthy eating and an exercise program.
A patient who is obese has sough care after failing to lose weight and keep it off through changes in diet and activity. The patient is being assessed to see if he would be a candidate for treatment with phentermine. What aspect of the patient's health would contraindicate the use of phentermine? A. The patient takes vitamin D and calcium supplements B. The patient takes beta-adrenergic blocker on a daily basis C. The patient's obesity is thought to have a genetic component D. The patient has a history of severe hypertension (NCLEX THE POINT)
ANSWER: D → Contraindications to phentermine use include moderate to severe hypertension, cardiovascular disease, and a history of drug abuse.
Many people who want to lose weight use dietary or herbal supplements for weight loss. Which of the following has been proven to be safe and effective? A. Hydrocycitric acid B. Guarana C. Glucomannan D. None (NCLEX THE POINT)
ANSWER: D → Many people use herbal or dietary supplements for weight loss, even though reliable evidence of safety and effectiveness are lacking. None of the three listed substances has been shown to be effective.
A patient with a long history of obesity has been gaining weight in the recent months and has consequently been prescribed phentermine. This drug will facilitate weight loss by which of the following means? A. Inhibiting digestion and absorption of fats B. Reducing gastric surface area C. Causing early satiation (sensation of fullness) D. Suppressing appetitie (NCLEX THE POINT)
ANSWER: D → Phentermine is an anorexiant, causing appetite suppression, which is thought to result from direct stimulation of the satiety center in the hypothalamic and limbic region.
In human nutrition, nutrients have specific roles, and excessive or deficient amounts impair health and cause illness. Which nutrient is the basic and functional component of all body cells and tissues? A. Carbohydrates B. Fats C. Water D. Proteins (NCLEX THE POINT)
ANSWER: D → Proteins are basic structural and functional components of all body cells and tissues; carbohydrates and fats serve primarily as sources of energy for cellular metabolism
Orlistat (Xenical) aids weight loss by A. Decreasing appetite B. Increasing satiety and feelings of fullness C. Increasing metabolism D. Decreasing absorption of dietary fat (NCLEX SUCCESS)
ANSWER: D → Taken with meals, orlistat binds to gastric and pancreatic lipases in the gastrointestinal tract and can block the absorption of 30% of ingested fat; increasing dosage does not increase this percentage.
A nurse is explaining to new patient how orlistat will aid his weight loss. The nurse should explain that orlistat will cause many of the fats that the patient eats to A. Be metabolized more efficiently B. Be stored in his liver rather than as subcutaneous fat C. Remain sequestered in his stomach for a longer period of time D. Pass through his GI tract unchanged (NCLEX THE POINT)
ANSWER: D → With the use of orlistat, triglycerides, cholesterol, and fat-soluble vitamins from fat-containing foods pass though the intestines unchanged and are not absorbed. The drug does not cause fats to accumulate in the liver or stomach.
Osteoarthritis: Health Risks of Obesity
Extra weight can stress affected bones & joints, contract muscles that normally stabilize joints, & alter the metabolism of cartilage, collagen, & bone. o Obese develop OA of the knees at an earlier age & are more likely than nonobese to require knee replacement surgery. Important role of obesity in OA is supported by the observation that weight loss delays onset & reduces symptoms & disability. Weight loss also decrease infection, wound complications, & blood loss if surgery is required. Despite the benefits of weight loss, persons with OA have difficulty losing weight because painful joints limit exercise & activity.
Orlistat (Xenical, Alli): Adverse Effects
GI symptoms: abdominal pain, oily spotting, fecal urgency & incontinence, Flatulence w/ discharge, fatty stools, & increased defecation. These effects occur in almost all users but subside after a few weeks of continued drug usage w/ moderation of fat intake.
Patient Teaching Guidelines for Weight Management and Drugs That Aid Weight Loss
General Considerations • Because of extensive health problems associated w/ overweight & obesity, if your weight is w/in normal range, try to prevent excessive weight gain by practicing a healthful lifestyle in terms of diet and exercise. Try to: - Manage weight by balancing calorie intake w/ physical activity. - Increase intake of fruits, vegetables, low-fat & fat-free dairy products, whole grains, & seafood - Limit intake of sodium, saturated & trans fats, cholesterol, refined grains, & foods w/ added sugars. - Spread your intake of daily fat, carbohydrate, & protein over 3 meals. • Further recommendations from the Dietary Guide-lines for Americans 2010, published by the U.S. Department of Health and Human Services and the Department of Agriculture in January 2011 (updated every 5 years) are available online at http://www.healthierus.gov/dietaryguidelines Self-Administration • Take appetite suppressants in the morning to decrease appetite during the day & avoid interference w/ sleep at night. • Do not crush/chew sustained-release products. • With phentermine, monitor your blood pressure. As body weight decreases, BP usually decreases. With orlistat (Xenical, Alli): o Take one capsule w/ each main meal or up to 1 hour after a meal, up to 3 capsules daily. If you miss a meal or eat a meal w/ no fat, you may omit a dose of orlistat. o Take multivitamin containing fat-soluble vitamins (A, D, E, & K) daily, at least 2 hours before or after taking orlistat. Orlistat prevents absorption of fat-soluble vitamins from food or multivitamin preparations if taken at the same time. o Take the drug with a full glass of water.
GI Drugs: Effects of Selected Medications on Weight
Increased appetite & weight gain w/ proton pump inhibitors such as omeprazole & others.
Clinical Manifestations
Increased body weight, excess body fat, & BMI score of 25 kg/m2+, abnormal levels of lipids & lipoproteins, elevated serum levels of insulin, elevated BP, & respiratory difficulties. Higher risk for HTN, heart disease, diabetes, joint problems, & sleep apnea.
Gallstones :Health Risks of Obesity
Increases risk for developing gallstones by altering production & metabolism of cholesterol & bile. Risk higher in women, those who have had multiple pregnancies or who are taking contraceptives. Rapid weight loss w/ low-calorie diets is also associated w/ gallstones.
Phentermine (Adipex-P, Ionamin, Pro-Fast): Action
Inhibits reuptake of serotonin & norepinephrine. An anorexiant, causing appetite suppression, which is thought to result from direct stimulation of the satiety center in the hypothalamic& limbic region.
Diabetes Mellitus: Health Risks of Obesity
Obesity in adolescence is associated w/ higher rates of diabetes as adults & also severe complications of diabetes at younger ages. o Proposed mechanisms include down-regulation of insulin receptors & abnormal postreceptor signals. Whatever the mechanism, the impaired insulin response stimulates the pancreatic beta cells to increase insulin secretion, resulting in a relative excess of insulin called hyperinsulinemia, & causes impaired lipid metabolism These metabolic changes increase HTN & other risk factors for cardiovascular disease. o Like cardiovascular disease & diabetes, central obesity increase serious diseases. Abdominal fat of central obesity is more insulin resistant than peripheral fat deposited over buttocks & legs. Intentional weight loss reduces mortality.
Miscellaneous Effects: Health Risks of Obesity
Obesity is associated with numerous difficulties. o Nownalcoholic fatty liver disease, which is being increasingly recognized and which may lead to liver failure o Poor wound healing o Poor antibody response to hepatitis B vaccine o A negative perception of people who are obese that affects their education, socioeconomic, & employment status o High cost of treatment of medical conditions caused/aggravated by obesity & costs associated w/ weight loss efforts o In women, obesity is associated w/ menstrual irregularities, difficulty becoming pregnant & increased complications of pregnancy. In men, obesity is associated with infertility. o In children & adolescents, obesity increases risk of bone fractures & muscle/joint pain. Knee pain is commonly reported, & changes in the knee joint make movement and exercise more difficult.
Antidiabetic: Effects of Selected Medications on Weight
Occurs w/ insulin, sulfonylureas, & glitazones. Gain weight when switched to insulin therapy. Mechanism is unknown; may be related to the chronic hyperinsulinism induced by long-acting insulins & the sulfonylureas. Less weight is gained when oral drugs are given during the day and intermediate- or long-acting insulin is injected at bedtime. Thought to cause less daytime hyperinsulinemia than the traditional insulin strategies. For near-normal-weight patients w/ diabetes who require drug therapy, a sulfonylurea may be given. For obese patients, metformin is drug of choice; used to treat obese diabetic children, aged 10 to 16 years, who require drug therapy.
Lipase Inhibitors
Orlistat (Xenical, Alli) is the prototype of the lipase inhibitors.
Age Concerns
Overweight & Obese Children • Overweight: BMI above the 85th percentile for the age group and obesity as a BMI above the 95th percentile. • At risk of developing HTN, dyslipidemias, type 2 diabetes m, & other disorders that lead to reduced quality of life, major disability, & death at younger adult ages. • Due to poor eating habits & little/no exercises • Obese after 6 years of age is highly likely to be obese adult & develop obesity-related health problems, especially if a parent is obese. Obesity in adults that began in childhood tends to be more severe. • Treatment should focus on healthy eating & increasing physical activity; never put on "diet." • For a child who is overweight, maintain weight or slow the rate of weight gain so that weight & BMI gradually decline as the child's height increases. • If child has already reached his/her anticipated adult weight, maintenance of that weight & prevention of additional gain should be the long-term treatment goal. If the child already exceeds his/her optimal adult weight, the goal of treatment should be a slow weight loss of 10 to 12 pounds per year until this weight is reached. Overweight and Obese Older Adults • The numbers are still significantly lower than in young adults; socioeconomic factors plays a role. Does not appear to make a difference to risks of death but is major contributor to increased disability & reduced quality of life. Development of type 2 diabetes m. remains a risk. Excess weight reduces the loss of bone mass, & less likely to suffer hip fractures; health risks of obesity are greater than any advantages.
Adrenergic Anorexiants
Phentermine (Adipex-P, Ionamin, Pro-Fast) is the prototype. Schedule IV drug is a sympathomimetic amine w/ pharmacologic activity similar to amphetamines.
Hormonal Contraceptives :Effects of Selected Medications on Weight
Related more to retention of fluid & sodium than to increased body fat.
Corticosteroids: Effects of Selected Medications on Weight
Systemic corticosteroids may cause increased appetite, weight gain, central obesity, & retention of sodium & fluid. Inhaled & intranasal have little effect on weight.
Phentermine (Adipex-P, Ionamin, Pro-Fast): Administering Medication
Take on an empty stomach. Take single-dose drugs early morning; take multiple-dose preparations 30 minutes before meals, w/ the last dose of the day about 6 hours before going to bed.
Phentermine (Adipex-P, Ionamin, Pro-Fast): Use
Used to speed weight loss in overweight. The drug is recommended only for short-term use (3 months or less). Combination with a healthy diet & exercise is important. o Use in Children: Pediatric clinicians suggest treatment for children who are overweight/obese & have complications of obesity. o Use in Older Adults: use very cautiously, if at all in older adults; often have cardiovascular, renal, or hepatic impairments that increase the risk of adverse drug effects. o Use in Renal Impairment: clearance may be decreased in renal impairment, resulting in increased risk of toxicity.
Mood-Stabilizing Agent: Effects of Selected Medications on Weight
Weight gain has been reported w/ long-term use of lithium. Increased weight due to fluid retention, consumption of high-calorie beverages due to increased thirst, or a decreased metabolic rate.
Phentermine (Adipex-P, Ionamin, Pro-Fast): Pharmacokinetics
administered orally & is excreted: kidneys. Under acidic urinary conditions,half-life is decreased.
Cancer: Health Risks of Obesity
higher prevalence of breast, colon & endometrial cancers. o W/ breast cancer, risks increase in postmenopausal women w/ increasing body weight. Women who gain more than 20 pounds from age 18 to midlife have double the risk of breast cancer compared with women who maintain a stable weight during this period of their life. Also, central obesity apparently increases the risk of breast cancer independent of overall obesity. In women with central obesity, this additional risk factor may be related to an excess of estrogen & a deficiency of sex hormone-binding globulin to combine w/ the estrogen. o Colon cancer more common in obese men/women. Also, a high BMI may be a risk factor for a higher mortality rate w/ colon cancer. Endometrial cancer more common in obese women, w/ adult weight gain again increasing risk.
Orlistat (Xenical, Alli): Contraindications
known allergy to the drug & chronic malabsorption syndrome or cholestasis.
Orlistat (Xenical, Alli): Preventing Interactions
• May reduce plasma concentrations of amiodarone. • By partially inhibiting the absorption of dietary fat, the weight management drug may also decrease the plasma concentration of cyclosporine, which is highly lipid-soluble; patients should take orlistat & cyclosporine 2 hours apart. Concomitant use of orlistat may increase the lipid-lowering effects of pravastatin. • May reduce absorption of fat-soluble vitamins. • QSEN: This has implications for monitoring coagulation parameters if orlistat is use in conjunction with warfarin. The liver uses vitamin K to make blood clotting proteins; therefore, a decreased in vitamin K increases the international normalized ratio and make it more difficult to manage warfarin therapy.
Phentermine (Adipex-P, Ionamin, Pro-Fast): Preventing Interactions
• People w/ diabetes m. may require increased doses of insulin because the drug produces effects similar to those caused by stimulating the sympathetic nervous system. • Drugs That Increase the Effects: other tricyclic antidepressants = Increase hypertensive effects • Other CNS stimulants = have additive stimulant effects • Other sympathomimetic drugs (e.g., epinephrine) = have additive hypertensive & other cardiovascular effects • Drugs That Decrease the Effects: antihypertensive drugs = decrease BP
Orlistat (Xenical, Alli): Patient Teaching
• Take one capsule w/ each main meal or up to 1 hour after a meal, up to 3 capsules daily. If you miss a meal or eat a meal w/ no fat, you may omit a dose of orlistat. • Take multivitamin containing fat-soluble vitamins (A, D, E, & K) daily, at least 2 hours before or after taking orlistat. Orlistat prevents absorption of fat-soluble vitamins from food or multivitamin preparations if taken at the same time. • Take the drug with a full glass of water.
(NHLBI) Report: Clinical Guidelines on the Identification, Evaluation, & Treatment of Overweight & Obesity in Adults
• Weight loss reduces health problems. Decrease BP if hypertensive; lower elevated levels of total cholesterol, low-density lipoprotein cholesterol, & triglycerides & raise low levels of high-density lipoprotein cholesterol if they are dyslipidemic; lower elevated blood glucose levels if they have type 2 diabetes. • BMI used to assess overweight & obesity & estimate disease risks. Measure waist circumference initially & periodically to assess abdominal fat content. Weigh regularly to monitor body weight for gain, loss, or maintenance. • Initial goal of weight loss therapy should be to reduce body weight by about 10% from baseline, at a rate of 1 to 2 pounds per week for 6 months. Steady weight loss over a longer period reduces fat stores in the body, limits the loss of vital protein tissues, & avoids sharp decline in metabolic rate that accompanies rapid weight loss. After weight loss, weight maintenance should be the priority goal; weight regain is a problem w/ all weight loss programs. After weight maintenance, additional losses may be desirable. • Dietary recommendations: low-calorie diets for weight loss, mainly reducing caloric intake by 500 to 1000 cal daily. Reducing dietary fat can reduce calories. Reducing dietary fat w/out reducing total caloric intake does not produce weight loss. Vitamin/mineral supplements that meet age-related requirements are usually recommended with weight loss programs that provide <1200 kcal for women & 1800 kcal for men. • Physical activity recommendations should be part of any weight management program because physical activity contributes to weight loss, may decrease abdominal fat, increases cardiorespiratory fitness, & helps w/ weight maintenance. Physical activity for 30 to 45 minutes, 3 to 5 days a week, is encouraged. On long term, adults should try to accumulate at least 30 minutes+ of moderate-intensity physical activity on most days of the week. • Weight loss & weight maintenance programs should combine reduced-calorie diets, increased physical activity, & behavior therapy. After weight loss, maintenance w/ dietary therapy, physical activity, & behavior therapy should be continued indefinitely. Drug therapy can also be used. However, drug safety and efficacy beyond 1 to 2 years of total treatment have not been established. • Behavioral modification can be helpful in a weight loss program. Goals are to help patients modify their eating, activity, & thinking habits. Techniques include identifying triggers that promote overeating & barriers that keep one from adopting a more healthful lifestyle. One strategy is keeping an accurate record of food/calorie intake & physical activity. Also, stress management, stimulus control, & social support help. Patients who eat more when stressed can learn to manage stress more healthfully. Counseling by behavioral therapist may be needed. Need social support.
