Prescription Prescription MedicationsMedications

David L. Gee, PhD

Professor of Food Science and Nutrition

Central Washington University

Major Categories of Major Categories of Weight Loss DrugsWeight Loss Drugs

Appetite SuppressantsInhibitors of Nutrient Absorption(Metabolic Stimulants)

Appetite Suppressants:Appetite Suppressants:

Serotonergic DrugsSerotonergic Drugs

Mechanism of action– elevated levels of serotonin reduce

appetite Serotonin levels increase after eatingserotonergic drugs

–Increase release of serotonin

Serotonergic DrugsSerotonergic DrugsA shaky historyA shaky history

FenfluramineDexfenfluramine (Redux)1997 FDA withdrew approval

status– Heart valve damage– Primary pulmonary hypertension

Appetite Suppresants:Appetite Suppresants:

Noradrenergic DrugsNoradrenergic Drugs

Mechanism of Action–elevation of norepinephrine–associated with satiety

Eating increases norepinephrinenoradrenergic drugs

Noradrenergic DrugsNoradrenergic DrugsPhenterminePhenylpropanolamine

– Dexatrim, Acutrim, PPA– Also as decongestant in cold medications– OTC– FDA warnings ( 2004)

hemorrhagic strokeremoving PPA from all products

Drugs that increase both Drugs that increase both serotonin and norepinephrineserotonin and norepinephrine

Sibutramine (Meridia)– increases serotonin and

norepinephrine by inhibiting their re-uptake

–FDA approval 1997

Sibutramine (Meridia)Sibutramine (Meridia)Mean wt loss: 10-14 pounds

– effects vary substantially

Side effects:– hypertension– dry mouth– headache– constipation

no sign of heart valve problems or PPH

Sibutramine (Meridia)Sibutramine (Meridia)

FDA regulations– affect manufacturers’ advertisement/promotion– does NOT regulate how physicians prescribe – for obese clients (BMI>30) or– for overweight clients with health risks

(BMI>27)– safe for one year use

Combined Drug TreatmentCombined Drug Treatment

fen/phen– fenfluramine/phenteramine– “off label use”– FDA: not tested for safety or effectiveness– Fenfluramine banned– Other combinations:

Ephedra-phenteramine

Inhibitors of Nutrient Inhibitors of Nutrient AbsorptionAbsorption

Orlistat (Xenical) – FDA approved 1999– pancreatic lipase inhibitor

inhibits absorption of dietary fatscauses steatorrheamay psychologically reduce fat/caloric

intake

Inhibitors of Nutrient Inhibitors of Nutrient AbsorptionAbsorption

Dietary Supplements– Chitin (fat malabsorption)– Starch Blockers (alpha amylase

inhibitors)– like all dietary supplements:

not tested for safety or effectivenessnot “approved” by FDA

Metabolic Metabolic StimulantsStimulants

Thyroid Hormone– only useful if TH deficient (rare)– results in significant LBM loss

Ephedra– dietary supplement– FDA investigating adverse effect claims

regulatory status in question

Long-term pharmacotherapy for overweight and Long-term pharmacotherapy for overweight and obesity: a systematic review and meta-analysis obesity: a systematic review and meta-analysis

of randomized controlled trials.of randomized controlled trials.Int. J. Obesity & Related Met. Dis. 27:1437-1446 (2003)Int. J. Obesity & Related Met. Dis. 27:1437-1446 (2003)

RCT’s published between 1966-2002– Double blind RCT of > 1 yr– BMI > 30 + comorbidities– Only two drugs w/ studies meeting these

criteria Orlistat/Xenical (11 studies, n=6021, mean

BMI=35.7, predominantly white females) Sibutramine/Meridia (3 studies, n=929, mean

BMI=33.4, predominantly white females)

Long-term pharmacotherapy for overweight and Long-term pharmacotherapy for overweight and obesity: a systematic review and meta-analysis obesity: a systematic review and meta-analysis

of randomized controlled trials.of randomized controlled trials.

Orlistat (Xenical)Mean weight loss = 2.7 kg

– 2.9% greater than placebo– 12% lost > 10% of body weight

33% attrition rateReductions in serum lipids, serum glucose,

blood pressure, lower HDL-CGastro-intestinal side effects

Long-term pharmacotherapy for overweight and Long-term pharmacotherapy for overweight and obesity: a systematic review and meta-analysis obesity: a systematic review and meta-analysis

of randomized controlled trials.of randomized controlled trials.

Sibutramine (Meridia)Mean weight loss = 4.3 kg

– 4.6% wt loss– 15% lost > 10% of body weight

48% attrition rateLower reductions in serum lipids than

orlistatIncreased blood pressure and pulse rate