Drugs for Gastrointestinal Diseases Practice Questions

Q: Which of the following drugs is NOT used in the management of obesity?

Neuropeptide Y Agonist. **Explanation:** The management of obesity involves drugs that either decrease nutrient absorption, suppress appetite (anorexiants), or increase energy expenditure. **Why Neuropeptide Y (NPY) Agonist is the correct answer:** Neuropeptide Y is one of the most potent **orexigenic** (appetite-stimulating) peptides found in the hypothalamus. It stimulates the Y1 and Y5 receptors to increase food intake and promote fat storage. Therefore, an **agonist** would cause weight gain, not loss. To treat obesity, one would theoretically use an NPY **antagonist**, though none are currently mainstay clinical treatments. **Analysis of Incorrect Options:** * **Orlistat:** A potent, reversible inhibitor of **gastric and pancreatic lipases**. It prevents the dietary breakdown of triglycerides into absorbable free fatty acids, reducing fat absorption by approximately 30%. * **Sibutramine:** A combined norepinephrine and serotonin reuptake inhibitor (SNRI). It acts as an anorexiant by increasing satiety. *Note: It has been withdrawn in many countries due to cardiovascular risks, but remains a classic "textbook" example of an anti-obesity drug.* * **Olestra:** A **non-absorbable fat substitute** used in food preparation. It mimics the texture of fat but cannot be hydrolyzed by digestive enzymes, thus contributing zero calories. **High-Yield Clinical Pearls for NEET-PG:** * **Liraglutide/Semaglutide:** GLP-1 receptor agonists are currently the "gold standard" for pharmacological weight loss. * **Lorcaserin:** A selective 5-HT$_{2C}$ receptor agonist (anorexiant). * **Qsymia:** A fixed-dose combination of Phentermine and Topiramate. * **Side Effect Tip:** Orlistat is notorious for causing **steatorrhea** (oily spotting) and deficiency of fat-soluble vitamins (A, D, E, K).

Q: Which drug is NOT used in the treatment of H. pylori infection?

Mosapride. **Explanation:** The treatment of *Helicobacter pylori* requires a combination of antibiotics and acid suppressants to eradicate the bacteria and promote ulcer healing [1][2]. **Why Mosapride is the correct answer:** **Mosapride** is a selective **5-HT₄ receptor agonist** used as a **prokinetic agent**. It enhances gastrointestinal motility by facilitating the release of acetylcholine from the enteric nervous system. While it is used for dyspepsia and GERD, it has no antimicrobial activity against *H. pylori* and is not part of any standard eradication regimen (e.g., Triple or Quadruple therapy). **Analysis of incorrect options:** * **Omeprazole (Option B):** A Proton Pump Inhibitor (PPI) that is a mandatory component of all *H. pylori* regimens [3]. It raises gastric pH, which increases the stability and efficacy of antibiotics like Amoxicillin and Clarithromycin. * **Metronidazole (Option A):** A nitroimidazole antibiotic frequently used in "Triple Therapy" (especially in penicillin-allergic patients) or "Quadruple Therapy" to target anaerobic components of the infection [2]. * **Amoxicillin (Option D):** A beta-lactam antibiotic that is a first-line agent in *H. pylori* eradication due to low resistance rates compared to other antibiotics [2]. **Clinical Pearls for NEET-PG:** * **Standard Triple Therapy (7-14 days):** PPI + Amoxicillin + Clarithromycin (Mnemonic: **PAC**) [2]. * **Bismuth Quadruple Therapy:** PPI + Bismuth subsalicylate + Metronidazole + Tetracycline (Used in areas with high Clarithromycin resistance) [2][3]. * **Sequential Therapy:** 5 days of PPI + Amoxicillin, followed by 5 days of PPI + Clarithromycin + Tinidazole. * **Diagnosis:** The **Urea Breath Test** is the non-invasive "Gold Standard" for confirming eradication.

Q: Levosulpiride acts as an antagonist of which central dopamine receptor?

All of the above. ### Explanation **Correct Answer: D. All of the above** **Mechanism of Action:** Levosulpiride is the levo-enantiomer of sulpiride, belonging to the substituted benzamide class. In the context of gastrointestinal pharmacology, it acts as a **selective dopamine (D2, D3, and D4) receptor antagonist**. While its prokinetic effect is primarily mediated by blocking **D2 receptors** at the peripheral level (which prevents dopamine-mediated inhibition of acetylcholine release), it also exerts potent antagonistic effects on central dopamine receptors. Research indicates that Levosulpiride has a high affinity for the **D2 and D3** receptors and also acts on the **D4** subtype. This broad-spectrum antagonism of the D-family receptors is why "All of the above" is the correct choice. **Analysis of Options:** * **A, B, and C:** While Levosulpiride is most famously associated with D2 blockade for its prokinetic and anti-emetic effects, it is not exclusive to D2. It binds to D3 and D4 receptors as well, making these options incomplete on their own. **Clinical Pearls for NEET-PG:** * **Dual Action:** It acts as a prokinetic (peripheral D2 blockade) and an antipsychotic/anti-emetic (central D2/D3/D4 blockade). * **Indications:** Commonly used for functional dyspepsia, diabetic gastroparesis, and GERD. * **Side Effects:** Because it crosses the blood-brain barrier and blocks central D2 receptors, it can cause **extrapyramidal symptoms (EPS)**, parkinsonism, and **hyperprolactinemia** (leading to galactorrhea or gynecomastia). * **Comparison:** Unlike Metoclopramide, Levosulpiride has negligible 5-HT3 antagonism or 5-HT4 agonism at standard doses; its primary prokinetic drive is purely dopaminergic.

Q: Teduglutide is used in small bowel syndrome because its action is similar to which of the following?

Glucagon like peptide 2. **Explanation:** **Teduglutide** is a recombinant analog of human **Glucagon-like Peptide-2 (GLP-2)**. It is specifically indicated for the treatment of **Short Bowel Syndrome (SBS)** in patients who are dependent on parenteral support. 1. **Mechanism of Action (Why C is correct):** GLP-2 is an enterotropic hormone secreted by L-cells of the distal intestine. Teduglutide mimics GLP-2 by binding to receptors on subepithelial myofibroblasts. This triggers the release of growth factors (like IGF-1) that promote **mucosal growth**, increase villus height, and deepen crypts. This expansion of surface area enhances the absorption of fluids and nutrients, reducing the need for intravenous parenteral nutrition. 2. **Why other options are incorrect:** * **A & B (Pancreatic/Biliary Lipase):** These are enzymes involved in the digestion of dietary fats. While fat malabsorption occurs in SBS, Teduglutide does not replace digestive enzymes; it restores the structural integrity of the bowel. * **D (Somatostatin):** Somatostatin (and its analog Octreotide) inhibits gastrointestinal motility and secretions. While sometimes used to reduce diarrhea in SBS, it does not promote intestinal adaptation or mucosal growth; in fact, it can sometimes inhibit the natural adaptive process. **NEET-PG High-Yield Pearls:** * **Half-life:** Teduglutide is modified (substitution of alanine with glycine) to be resistant to degradation by the enzyme **DPP-4**, giving it a significantly longer half-life than native GLP-2. * **Monitoring:** Because it promotes cell growth, patients must be monitored via colonoscopy for **intestinal polyps** or malignancy before and during treatment. * **Other GLP analogs:** Do not confuse GLP-2 (Teduglutide - GI) with **GLP-1** (Exenatide, Liraglutide - Diabetes/Obesity).

Q: The following adverse drug reaction seen in colonoscopy view is due to which of the following agents?

Cascara. ***Cascara*** - **Melanosis coli** (dark brown/black pigmentation of colonic mucosa) is a characteristic adverse effect of chronic **anthraquinone laxative** use, including cascara. - The pigmentation results from **lipofuscin deposits** in macrophages within the lamina propria, visible on colonoscopy as dark discoloration. *Bisacodyl* - This is a **stimulant laxative** that works by increasing intestinal motility but does not cause melanosis coli. - Chronic use may lead to **electrolyte imbalances** and **cathartic colon**, but not the characteristic pigmentation seen in the image. *Castor oil* - Acts as a **ricinoleic acid-based stimulant laxative** that increases intestinal secretions and motility. - Does not contain **anthraquinones** and therefore does not cause the dark pigmentation of melanosis coli. *Loperamide* - This is an **anti-diarrheal agent** that works as an **opioid receptor agonist** to slow intestinal motility. - Would not cause melanosis coli and is therapeutically opposite to laxatives in function.

Q: Which of the following drugs does NOT cause peptic ulcers?

Cyclosporine. ### Explanation The correct answer is **Cyclosporine**. **1. Why Cyclosporine is the correct answer:** Cyclosporine is a calcineurin inhibitor used as an immunosuppressant. Unlike the other options, it is **not** associated with the development of peptic ulcer disease (PUD). Its primary toxicities are nephrotoxicity, hypertension, gingival hyperplasia, and hirsutism. While it may cause mild GI upset (nausea/vomiting), it does not disrupt the gastric mucosal barrier or increase acid secretion. **2. Analysis of incorrect options:** * **Diclofenac:** As a non-selective NSAID, it inhibits COX-1 and COX-2 enzymes. Inhibition of COX-1 leads to decreased synthesis of protective prostaglandins ($PGE_2$ and $PGI_2$), which are essential for mucus and bicarbonate secretion. This is a classic cause of drug-induced peptic ulcers. * **Potassium Chloride (KCl):** Oral KCl supplements, especially in tablet form, are highly irritating to the GI mucosa. They can cause local caustic injury, leading to "pill-induced" ulcers, particularly in the esophagus or small bowel, but also the stomach. * **Clopidogrel:** While clopidogrel does not directly cause ulcers, it is an antiplatelet agent that inhibits ADP-induced platelet aggregation. It impairs the healing of pre-existing subclinical erosions (often caused by *H. pylori* or NSAIDs) and significantly increases the risk of GI bleeding from existing ulcers. **3. NEET-PG High-Yield Pearls:** * **Steroids vs. NSAIDs:** Corticosteroids alone have a low risk of causing ulcers, but they **synergistically increase** the risk of PUD when combined with NSAIDs. * **Bisphosphonates:** (e.g., Alendronate) are another common cause of severe pill-induced esophagitis and gastric ulcers. * **Prophylaxis:** For patients at high risk of NSAID-induced ulcers, **Misoprostol** ($PGE_1$ analogue) or **PPIs** are the drugs of choice for prevention.

Q: Gynaecomastia may be associated with the administration of which drug?

Cimetidine. **Explanation:** **Cimetidine** is a first-generation H2-receptor antagonist that is notorious for causing endocrine side effects, specifically **gynaecomastia** in men and galactorrhea in women. This occurs due to two primary mechanisms: 1. **Anti-androgenic effects:** It binds to androgen receptors and inhibits the action of dihydrotestosterone (DHT). 2. **Inhibition of Estradiol metabolism:** It inhibits the cytochrome P450 enzymes responsible for the hydroxylation of estradiol, leading to increased systemic estrogen levels. 3. **Hyperprolactinemia:** It can occasionally increase prolactin levels when given in high doses intravenously. **Analysis of Incorrect Options:** * **Ranitidine:** While also an H2 blocker, it is much more potent than cimetidine and lacks the anti-androgenic properties. It does not typically cause gynaecomastia. * **Terfenadine:** This is a non-sedating H1-receptor antagonist (antihistamine). It is clinically significant for causing QT prolongation (Torsades de pointes) when co-administered with CYP3A4 inhibitors, but it has no hormonal side effects. * **Omeprazole:** A Proton Pump Inhibitor (PPI). While long-term use can lead to Vitamin B12 deficiency or osteoporosis, it is not classically associated with gynaecomastia. **NEET-PG High-Yield Pearls:** * **Cimetidine is a potent Enzyme Inhibitor:** It inhibits multiple CYP450 isoenzymes (1A2, 2C9, 2D6, 3A4), leading to significant drug interactions with Warfarin, Phenytoin, and Theophylline. * **Other common drugs causing Gynaecomastia (Mnemonic: DISCO):** **D**igoxin, **I**soniazid, **S**pironolactone, **C**imetidine, **O**estrogens/Ketoconazole. * Among H2 blockers, **Famotidine** is the most potent and has the longest duration of action, with the fewest side effects.

Q: Indicate the drug which does not improve lower esophageal sphincter tone or prevent gastroesophageal reflux, but is used as the first-line treatment of gastroesophageal reflux disease?

Omeprazole. ### Explanation The management of Gastroesophageal Reflux Disease (GERD) focuses on two primary strategies: increasing the Lower Esophageal Sphincter (LES) tone to prevent reflux and reducing the acidity of the gastric contents. **Why Omeprazole is correct:** Omeprazole is a **Proton Pump Inhibitor (PPI)**. It works by irreversibly inhibiting the $H^+/K^+$-ATPase pump in gastric parietal cells, thereby profoundly reducing gastric acid secretion. While it is the **first-line treatment** and the most effective drug for healing esophagitis and providing symptom relief, it has **no effect on LES tone** or the frequency of transient LES relaxations. It treats the *consequences* of reflux (acid damage) rather than the *mechanical cause*. **Analysis of Incorrect Options:** * **Sodium alginate + aluminium hydroxide:** Alginates react with gastric acid to form a viscous "raft" that floats on top of gastric contents, acting as a **physical barrier** to prevent reflux. * **Mosapride:** A selective $5-HT_4$ agonist that acts as a **prokinetic**. It increases LES tone and enhances gastric emptying, addressing the physiological defect of GERD. * **Metoclopramide:** A $D_2$ receptor antagonist with prokinetic properties. It **increases LES tone** and stimulates upper GI motility. However, it is not first-line due to side effects like extrapyramidal symptoms. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice (DOC):** PPIs (e.g., Omeprazole, Pantoprazole) are the DOC for all grades of GERD and Peptic Ulcer Disease. * **Administration:** PPIs should be taken **30–60 minutes before breakfast** for maximal efficacy, as they require active pumps to bind. * **Nocturnal Acid Breakthrough:** Often managed by adding an $H_2$ blocker (like Famotidine) at bedtime. * **Surgical Gold Standard:** Nissen Fundoplication is the surgical treatment of choice for refractory GERD.

Question 1

Which of the following drugs is NOT used in the management of obesity?

Accepted Answer

Neuropeptide Y Agonist

Answer

Orlistat

Answer

Sibutramine

Answer

Olestra

Question 2

What is the drug of choice for the medical management of bleeding esophageal varices?

Accepted Answer

Octreotide

Answer

Terlipressin

Answer

Propranolol

Answer

Clonidine

Question 3

Which drug is NOT used in the treatment of H. pylori infection?

Accepted Answer

Mosapride

Answer

Metronidazole

Answer

Omeprazole

Answer

Amoxicillin

Question 4

What is true regarding sulfasalazine?

Accepted Answer

Active moiety is 5-aminosalicylic acid in ulcerative colitis.

Answer

Inactive moiety is 5-aminosalicylic acid in ulcerative colitis.

Answer

Inactive moiety in rheumatoid arthritis is sulfapyridine.

Answer

It gets activated in the stomach.

Question 5

Levosulpiride acts as an antagonist of which central dopamine receptor?

Accepted Answer

All of the above

Answer

D2

Answer

D3

Answer

D4

Question 6

Teduglutide is used in small bowel syndrome because its action is similar to which of the following?

Accepted Answer

Glucagon like peptide 2

Answer

Pancreatic lipase

Answer

Biliary lipase

Answer

Somatostatin

Question 7

The following adverse drug reaction seen in colonoscopy view is due to which of the following agents?

Accepted Answer

Cascara

Answer

Bisacodyl

Answer

Castor oil

Answer

Loperamide

Question 8

Which of the following drugs does NOT cause peptic ulcers?

Accepted Answer

Cyclosporine

Answer

Potassium Chloride

Answer

Diclofenac

Answer

Clopidogrel

Question 9

Gynaecomastia may be associated with the administration of which drug?

Accepted Answer

Cimetidine

Answer

Ranitidine

Answer

Terfenadine

Answer

Omeprazole

Question 10

Indicate the drug which does not improve lower esophageal sphincter tone or prevent gastroesophageal reflux, but is used as the first-line treatment of gastroesophageal reflux disease?

Accepted Answer

Omeprazole

Answer

Sodium alginate + aluminium hydroxide gel

Answer

Mosapride

Answer

Metoclopramide

Drugs for Gastrointestinal Diseases — MCQs

Drugs for Gastrointestinal Diseases — MCQs

On this page

Practice by Chapter

Want unlimited practice?