Which of the following enzymes is not targeted by hypolipidemic drugs?

Acyl CoA, cholesterol acyl transferase 1

What is the mechanism of action of Tegaserod?

Dopamine D2 receptor antagonist

A 50-year-old woman, who is 5 feet 7 inches tall and weighs 185 pounds, has a family history of diabetes mellitus. Her fasting blood glucose levels are 160 mg/dL and 155 mg/dL on two occasions, and her HbA1c level is 7.9%. After being educated on medical nutrition therapy, she returns for reevaluation in 8 weeks, reporting that she has followed diet and exercise recommendations, but her fasting blood glucose levels remain between 140 and 150 mg/dL, and her HbA1c level is 7.7%. She is asymptomatic, and physical examination reveals no abnormalities. Which of the following treatments is the most appropriate for her condition?

A dipeptidyl peptidase-4 (DPP-4) inhibitor

Appetite is stimulated by all except

Melanocyte concentrating hormone

Pharmacological Management of Obesity for FMGE: High-Yield Pharmacology Lessons

Indications & Goals - Weighing the Options

Primary Goal: Achieve clinically significant weight loss (≥ 5-10% of initial body weight) to mitigate obesity-related health risks.
Indications (Indian/Asian Adults):
- BMI ≥ 25 kg/m² (Obesity).
- BMI ≥ 23 kg/m² (Overweight) with ≥ 1 significant comorbidity (e.g., T2DM, hypertension, dyslipidemia, OSA, CVD).
Pre-requisite: Pharmacotherapy is considered after failure of comprehensive lifestyle interventions (diet, physical activity, behavioral changes) for at least 3-6 months.
Key Considerations: Patient motivation, realistic goals, risk-benefit assessment for individual agents.

⭐ Pharmacotherapy for obesity is an adjunct to, not a substitute for, sustained lifestyle modifications.

Central Mechanisms - Brainy Weight Busters

Central agents modulate neurotransmitters or receptors in the hypothalamus (appetite regulation center) or reward pathways to reduce appetite or increase satiety.

Agent	MOA Highlights	Avg. Wt. Loss	Key AEs/CIs (⚠️)
Phentermine/Topiramate	NE release (↓appetite); GABA-R modulation (↑satiety)	~9-11%	Tachycardia, paresthesia. ⚠️ Glaucoma, hyperthyroidism, MAOI use. Teratogenic.
Naltrexone/Bupropion	µ-opioid antagonist + DA/NE reuptake inhibitor (↓cravings, ↑POMC)	~5-9%	Nausea, headache. ⚠️ Seizures, uncontrolled HTN, opioid use. Black Box: Suicidality.
Liraglutide (Saxenda)	GLP-1 RA (↑satiety, ↓gastric emptying) 📌 '-glutide'	~5-8% (3mg)	GI (nausea, vomiting), pancreatitis. ⚠️ Hx MTC/MEN2.
Semaglutide (Wegovy)	GLP-1 RA (↑satiety, ↓gastric emptying) 📌 '-glutide'	~15-17% (2.4mg)	GI (nausea, vomiting), pancreatitis. ⚠️ Hx MTC/MEN2.

⭐ > Naltrexone/Bupropion synergistically targets both hypothalamic melanocortin pathways (reducing hunger) and mesolimbic reward pathways (reducing cravings).

Peripheral Mechanisms - Gut Feeling Fighters

Orlistat (Xenical, Alli)
- MOA: Reversible inhibitor of pancreatic & gastric lipases.
  - Prevents hydrolysis of dietary triglycerides.
  - ↓ dietary fat absorption by ~30%.
- Dose: 120 mg TID (with main meals containing fat).
- Side Effects:
  - GI: Steatorrhea (oily spotting, flatus with discharge, fecal urgency). 📌 'Oily'stat.
  - ↓ absorption of fat-soluble vitamins (A, D, E, K) - supplement 2 hours apart.
- Interactions: Warfarin (↑ INR via ↓ Vit K), Cyclosporine (↓ levels - administer 2-3 hours apart).
⭐ Orlistat is a peripherally acting lipase inhibitor; it does not affect appetite or satiety centers in the brain.

Drug Comparison & Safety - Safe Slimming Strategies

Drug Comparison: Key Features

Drug	MOA	Efficacy (Avg. WL)	Key AEs	Key CIs
Orlistat	Inhibits pancreatic/gastric lipase; ↓fat absorption	~3-5%	GI: Steatorrhea, fecal urgency, oily spotting	Chronic malabsorption, cholestasis
Liraglutide	GLP-1 RA: ↑satiety, ↓appetite, delays gastric emptying	~5-8%	N/V/D, pancreatitis risk	Hx Medullary Thyroid Ca (MTC)/MEN2
Semaglutide	GLP-1 RA: Potent; ↑satiety, ↓appetite, delays gastric emptying	~10-15%	N/V/D (often dose-dep.), pancreatitis risk	Hx MTC/MEN2
Naltrexone/Bupropion	Naltrexone (opioid antag) + Bupropion (NDRI): Modulates appetite	~5%	Nausea, headache, insomnia, ↑BP/HR	Seizures, uncontrolled HTN, MAOI use, chronic opioid use

*   Goal: Clinically significant weight loss (≥**5%**).
*   Discontinue if <**5%** weight loss at **3 months** (12 weeks).
*   ⚠️ All generally contraindicated in pregnancy, breastfeeding.

⭐ GLP-1 RAs (Liraglutide, Semaglutide) offer cardiovascular benefits in T2DM patients, a crucial advantage beyond weight loss.

Simplified Drug Selection Flow

High‑Yield Points - ⚡ Biggest Takeaways

Orlistat: Lipase inhibitor; causes steatorrhea, fat-soluble vitamin deficiency. Monitor INR with warfarin.

GLP-1 agonists (Liraglutide, Semaglutide): Suppress appetite, delay gastric emptying; nausea common. Thyroid C-cell tumor risk.

Naltrexone/Bupropion: Opioid antagonist + DA/NE reuptake inhibitor. BBW: Suicidality.

Phentermine/Topiramate: Sympathomimetic + antiepileptic. Short-term use; CV risks, teratogenic.

Setmelanotide: MC4R agonist for rare genetic obesities (POMC, PCSK1, LEPR).

Crucial: Note contraindications (e.g., pregnancy, MAOIs) & key AEs for each drug class.

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