The Skinny On Weight Loss Drugs

1
The Skinny On Weight Loss Drugs

• Siggi Ming, ARNP, NP-C
• Weight Loss Center of Oklahoma

2
Objectives

• Learner will be able to identify pharmacological
  agents currently approved by the FDA for the
  treatment of obesity
• Learner will be able to identify indications for
  the use of pharmacological agents when treating
  overweight/obese patients
• Learner will be able to discuss the use of
  pharmacological agents in combination with
  behavior modification, nutrition, and use of
  supplements in the treatment of overweight/obesity

3
Definition of Overweight/Obesity

• Overweight BMI of 25.0 29.9 kg/m2
• Obese BMI of 30.0 39.9 kg/m2
• Morbidly Obese BMI of 40.0 kg/m2 and gt

4
When to Treat

• Any time comorbidities are present, i.e. DM II,
  hyperlipidemias, heart disease, GERD,
  hypertension, metabolic syndrome, sleep apnea,
  stress incontinence
• Any time the patient requests help with weight
  loss efforts

5
How Is Overweight/Obesity Treated?

• Behavior Modification and Lifestyle Changes
• Nutritional Counseling
• Exercise Counseling
• Correcting Endocrine Imbalances
• Supplements
• Prescription Medications

6
Pharmacologic Agents

• Orlistat
• The only FDA approved drug for long
• term use
• Lipase Inhibitor inhibits absorption of dietary
  fat
• Minimal systemic absorption
• Tmax approx. 8 hrs
• Half life approx. 1-2 hrs
• Metabolism occurs mainly in GI wall
• Elimination via fecal route (97)

7
Orlistat Indications Dosage

• Obesity Management
• Weight Loss
• Weight maintenance
• 120 mg po tid with or lt 1 hr after fat containing
  meal
• Omit if meal is non-fat

8
Orlistat Contraindications

• Hypersensitivity
• Chronic malabsorption syndromes
• Cholestasis
• Hx of calcium oxalate kidney stones
• Hx of Anorexia or bulimia
• Hx of organ transplant

9
Orlistat Adverse Reactions

• Serious
• Hypersensitivity (anaphylaxis)
• Angioedema
• Vitamin deficiencies (fat soluble vit)
• hepatotoxicity

10
Orlistat Adverse Reactions

• Common
• Oily spotting
• Flatulence with fecal discharge
• Fecal urgency and incontinence
• Fatty, oily stools
• Abdominal discomfort

11
Orlistat Drug Interactions

• Warfarin Watch for increased INR due to
  decreased Vitamin K absorption
• Cyclosporine Decreased levels
• Amiodarone Decreased levels
• Fat soluble vitamins (K, A, D, E) Decreased
  absorption
• Thyroid hormone Decreased absorption

12
Orlistat Safety

• Pregnancy Category B
• Lactation safety unknown
• Monitoring no routine testing recommended

13
Drugs approved for short term use

• Phentermine
• Diethylpropion
• Phendimetrazine

14
Phentermine

• FDA approved for short term use (up to 12 weeks)
• Sympathomimetic stimulates CNS activity
  stimulates catecholamine release, thereby
  decreasing hunger
• Rapidly absorbed from GI tract
• Half life approx. 24 hrs
• Excretion 70-80 unchanged in urine

15
Phentermine Indications Dosage

• Short term treatment of obesity
• 37.5 mg po qd before 1000 to avoid insomnia
• Start with ½ strength
• Increase dosage to full strength if ½ strength
  not causing enough appetite suppression

16
Phentermine Contraindications

• Hypersensitivity
• MAOI use
• Arteriosclerosis
• Cardiovascular disease
• Hyperthyroidism
• Glaucoma
• Agitation
• Hx of drug abuse
• Pregnancy
• Breastfeeding

17
Phentermine Adverse Reactions

• Serious
• Dependency
• Psychosis
• Tachycardia
• Hypertension
• Pulmonary hypertension
• Valvular heart disease

18
Phentermine Adverse Reactions

• Common
• Palpitations
• Tachycardia
• Restlessness
• Insomnia
• Diarrhea
• Xerostomia
• Hypertension
• Euphoria
• Headache

19
Phentermine Drug Interactions

• Anorexiants/stimulants (increased risk of CV, CNS
  stimulation)
• MAOIs (hypertensive crisis)
• Linezolid (increased risk for HTN)
• Effexor (additive effect)

20
Phentermine Safety

• Pregnancy Category C
• Lactation possibly unsafe
• CV evaluation at baseline (ECG, BP, physical CV
  exam consider echo at baseline and after dc)
• Schedule IV

21
Diethylpropion

• FDA approved for short term use (up to 12 weeks)
• Sympathomimetic stimulates CNS activity
  stimulates catecholamine release, thereby
  decreasing hunger
• Rapidly absorbed
• Half life 4-6 hrs
• Excretion urine

22
Diethylpropion Indications Dosage

• Short term treatment of obesity
• 25 mg po up to tid 75 mg ER qd
• 25 mg approx. 1 hr before hungriest time of
  day may take up to tid
• Do not take after 1600 to avoid insomnia
• 75 mg ER q am

23
Diethylpropion Contraindications

• Hypersensitivity
• Pulmonary hypertension
• Severe hypertension
• Agitation
• Valvular heart disease
• Heart murmur
• Cardiovascular disease
• Seizure disorder
• Advanced arteriosclerosis

24
Diethylpropion Adverse Reactions

• Serious
• Tachycardia
• Hypertension
• Pulmonary hypertension
• Valvular heart disease
• Hallucinations
• Psychosis
• Leukopenia

25
Diethylpropion Adverse Reactions

• Common
• Dry mouth
• Diarrhea/constipation
• Restlessness
• Anxiety
• Insomnia
• Headache
• Hypertension
• Palpitations
• Arrhythmias

26
Diethylpropion Drug Interactions

• Anorexiants/stimulants (increased risk of CV and
  CNS stimulation
• MAOIs (hypertensive crisis)
• Linezolid (increased risk of HTN)
• Effexor (additive effects)

27
Diethylpropion Safety

• Pregnancy Category B
• Lactation safety unknown
• Cardiovascular evaluation at baseline ECG, BP,
  physical CV exam)
• Consider echo periodically and after dc
• Schedule IV

28
Phendimetrazine

• FDA approved for short term use (up to 12 weeks)
• Sympathomimetic stimulates CNS activity
  stimulates catecholamine release, thereby
  decreasing hunger
• Rapidly absorbed
• Half life 2 hrs (10 hrs ER)
• Excretion urine

29
Phendimetrazine Indications Dosage

• Short term treatment of obesity
• 17.5-35 mg po bid-tid 1 hr ac
• Do not give after 1600 to avoid insomnia
• 105 mg ER po q am 30-60 mins ac

30
Phendimetrazine Contraindications

• Hypersensitivity
• Symptomatic cardiovascular disease
• Moderate/severe hypertension
• Hyperthyroidism
• Agitation
• MAOI use
• Valvular heart disease
• Pregnancy
• Glaucoma
• Advanced arteriosclerosis

31
Phendimetrazine Adverse Reactions

• Serious
• Hypertension
• Tachycardia
• Pulmonary hypertension
• Withdrawal if abrupt dc after long term high-dose
  use

32
Phendimetrazine Adverse Reactions

• Common
• Palpitations
• Tachycardia
• Restlessness
• Hypertension
• Insomnia
• Agitation
• Dizziness
• Headache
• Flushing
• Sweating
• Tolerance
• Diarrhea/constipation

33
Phendimetrazine Drug Interactions

• Anorexiants/stimulants (increased risk of CV and
  CNS stimulation
• MAOIs (hypertensive crisis)
• Linezolid (increased risk of HTN)
• Effexor (additive effects)

34
Phendimetrazine Safety

• Pregnancy Category C
• Lactation possibly unsafe
• Cardiovascular evaluation at baseline ECG, BP,
  physical CV exam
• Consider echo periodically and after dc
• Schedule III

35
Drugs Used Off Label

• Pristiq
• Antidepressant (SNRI)
• Side effects include decreased appetite, weight
  loss
• Seems to decrease cravings

36
Drugs Used Off Label

• Topamax
• For migraine/headache seizure disorders
• Side effects include weight loss, anorexia
• Many undesirable side effects

37
Drugs Used Off Label

• Spironolactone
• Decreases CHO cravings
• Useful prior to menses
• Start the day premenstrual S/S begin, stop when
  menstrual flow ceases

38
Drugs Used Off Label

• Pindolol
• Weak beta blocker
• Use with phentermine, diethylpropion to block
  stimulant effect without affecting anorectic
  effect

39
hCG

• Human chorionic gonadotropin
• Hormone secreted by the female body in response
  to pregnancy
• Used off and on since the 1950s in conjunction
  with a very low calorie diet (usually 500
  kcal/day)

40
hCG

• No evidence that hCG is associated with weight
  loss
• No evidence that the use of hCG is safe
• ASBP strongly discourages the use of hCG for
  weight loss

41
Supplements

• Good quality supplements can aid weight loss
  efforts by
• - raising resting metabolic rate
• - increasing lipid metabolism
• - curbing hunger
• - raising energy levels

42
Combined Effort

• Nutrition
• Behavior
• Lifestyle
• Medications/Supplements