Which of the following antineoplastic drugs SHOULD NOT be given by rapid IV infusion?
What is Dinoprost?
Which diuretic exhibits paradoxical antidiuretic activity in diabetes insipidus?
Which steroid has the maximum mineralocorticoid activity?
Which statin is considered most potent based on mg-to-mg LDL reduction capability?
Which of the following antiepileptic drugs is most classically associated with causing hirsutism?
What is the iodine content percentage in amiodarone?
Which of the following medications is known to cause increased renin levels with prolonged use?
Which of the following is NOT caused by Prostaglandin E2 (PGE2)?
Which drug is commonly used for outpatient department (OPD) analgesia?
NEET-PG 2012 - Pharmacology NEET-PG Practice Questions and MCQs
Question 61: Which of the following antineoplastic drugs SHOULD NOT be given by rapid IV infusion?
- A. Cyclophosphamide
- B. Cytosine arabinoside
- C. Cisplatin (Correct Answer)
- D. Bleomycin
Explanation: ***Cisplatin*** - **Cisplatin** is highly nephrotoxic and emetogenic; rapid IV infusion can exacerbate these adverse effects, leading to severe renal damage and intractable nausea/vomiting. - It typically requires **prolonged infusion times** (e.g., 6-8 hours) with extensive pre- and post-hydration to reduce kidney toxicity and ensure patient tolerance. *Cyclophosphamide* - While cyclophosphamide can cause **hemorrhagic cystitis**, this is managed by adequate hydration and mesna, and its infusion rate is generally not as critically prolonged as cisplatin's. - It is often administered as a **relatively quick IV infusion** over 30-60 minutes, emphasizing hydration. *Bleomycin* - **Bleomycin** is known for pulmonary toxicity and hypersensitivity reactions, but these are not primarily linked to its infusion rate. - It is commonly given via **slow IV push or short infusion**, sometimes with a test dose to assess for hypersensitivity. *Cytosine arabinoside* - **Cytosine arabinoside** can cause myelosuppression and cerebellar toxicity, but these toxicities are not typically exacerbated by a rapid infusion rate. - It is often administered via a **continuous infusion** over several days or as a rapid IV bolus.
Question 62: What is Dinoprost?
- A. Prostaglandin E2 (PGE2)
- B. Prostaglandin F2α (PGF2α) (Correct Answer)
- C. Prostaglandin I2 (PGI2)
- D. Prostaglandin E1 (PGE1)
Explanation: ***Prostaglandin F2α (PGF2α)*** - **Dinoprost** is the generic name for **Prostaglandin F2α**. - It works by stimulating **myometrial contractions** and promoting cervical ripening, making it useful in obstetrics. *Prostaglandin E2 (PGE2)* - **PGE2** is known as **Dinoprostone** and is also used for cervical ripening and labor induction. - While similar in function, **Dinoprostone** (PGE2) is distinct from **Dinoprost** (PGF2α). *Prostaglandin I2 (PGI2)* - **PGI2** is also known as **Prostacyclin** and acts as a potent **vasodilator** and **inhibitor of platelet aggregation**. - Its primary therapeutic uses are in conditions like **pulmonary hypertension**, which differs from Dinoprost's obstetric uses. *Prostaglandin E1 (PGE1)* - **PGE1** is also known as **Alprostadil** and is used to maintain the **patency of the ductus arteriosus** in neonates with certain congenital heart defects. - It is distinct from Dinoprost and has different clinical applications.
Question 63: Which diuretic exhibits paradoxical antidiuretic activity in diabetes insipidus?
- A. Thiazide diuretics (Correct Answer)
- B. Aldosterone antagonists (Spironolactone)
- C. Loop diuretics (Furosemide)
- D. Potassium-sparing diuretics (Triamterene)
Explanation: ***Thiazide diuretics*** - Thiazides cause a modest **volume depletion**, leading to increased proximal tubular reabsorption of water and solutes [1]. - They also lower the **glomerular filtration rate**, further reducing the amount of fluid delivered to the collecting ducts, thus paradoxically reducing urine output in diabetes insipidus [2]. - This effect is particularly useful in **nephrogenic diabetes insipidus**, where the kidneys cannot respond to ADH [2]. *Potassium-sparing diuretics (Triamterene)* - Triamterene is a **potassium-sparing diuretic** that blocks epithelial sodium channels in the late distal tubule and collecting duct. - It increases sodium and water excretion, which would worsen, not improve, the polyuria of diabetes insipidus. *Aldosterone antagonists (Spironolactone)* - Spironolactone is a **mineralocorticoid receptor antagonist** that increases sodium and water excretion while conserving potassium in the collecting duct. - Its primary action is to counteract aldosterone, and it does not exhibit the paradoxical antidiuretic effect seen with thiazides in diabetes insipidus. *Loop diuretics (Furosemide)* - Loop diuretics like furosemide act on the **thick ascending limb of the loop of Henle** to inhibit sodium, potassium, and chloride reabsorption. - They cause significant diuresis and would **exacerbate the polyuria** in patients with diabetes insipidus, rather than improving it.
Question 64: Which steroid has the maximum mineralocorticoid activity?
- A. Fludrocortisone (Correct Answer)
- B. DOCA
- C. Prednisolone
- D. Triamcinolone
Explanation: ***Fludrocortisone*** - **Fludrocortisone** is a synthetic corticosteroid specifically designed to have potent **mineralocorticoid activity**, with significant sodium-retaining properties. - Its high affinity for **mineralocorticoid receptors** distinguishes it from other steroids and makes it effective in treating conditions like **Addison's disease** and **postural orthostatic tachycardia syndrome (POTS)** due to its ability to retain sodium and water. *DOCA (Deoxycorticosterone acetate)* - While **DOCA** does possess significant **mineralocorticoid activity** and was historically used for this purpose, **fludrocortisone** is generally considered to have a stronger and more sustained effect in clinical practice. - **DOCA's** mineralocorticoid potency is substantial but slightly less than that of **fludrocortisone** when compared on a weight basis for equivalent sodium retention. *Prednisolone* - **Prednisolone** is primarily a **glucocorticoid** with potent anti-inflammatory and immunosuppressive effects. - It has minimal to negligible **mineralocorticoid activity** and is not used for salt retention purposes. *Triamcinolone* - **Triamcinolone** is a potent **glucocorticoid** with a long duration of action and is known for its strong anti-inflammatory properties. - It has virtually no **mineralocorticoid activity**, making it unsuitable for conditions requiring sodium retention.
Question 65: Which statin is considered most potent based on mg-to-mg LDL reduction capability?
- A. Simvastatin
- B. Pravastatin
- C. Rosuvastatin (Correct Answer)
- D. Atorvastatin
Explanation: ***Rosuvastatin*** - **Rosuvastatin** is known for its high potency, achieving significant **LDL-C reduction** at relatively low doses. - It is often considered the most potent statin on a **milligram-to-milligram basis**. *Simvastatin* - **Simvastatin** is a moderate-intensity statin, not as potent as rosuvastatin or atorvastatin in reducing LDL-C. - While effective, it typically requires higher doses to achieve comparable **LDL-C reductions** seen with high-potency statins. *Pravastatin* - **Pravastatin** is a hydrophilic statin, generally considered to be of lower potency compared to other statins like rosuvastatin and atorvastatin. - It is often used in patients with **hepatic dysfunction** due to its different metabolic profile but offers less aggressive **LDL-C reduction**. *Atorvastatin* - **Atorvastatin** is a high-intensity statin, very effective in reducing LDL-C, and often used for aggressive lipid lowering. - While highly potent, **atorvastatin** is generally considered slightly less potent than **rosuvastatin** on a mg-to-mg basis, though both are used for high-intensity lipid therapy.
Question 66: Which of the following antiepileptic drugs is most classically associated with causing hirsutism?
- A. Phenytoin (Correct Answer)
- B. Valproate
- C. Carbamazepine
- D. Phenobarbitone
Explanation: ***Phenytoin*** - **Phenytoin** is the **most classically associated** antiepileptic drug with **hirsutism**, which is abnormal/excessive growth of hair [1]. - The mechanism involves changes in **androgen metabolism** and stimulation of hair follicle growth. - Other cosmetic side effects include **gingival hyperplasia** and **coarsening of facial features** [1].*Valproate* - Valproate can paradoxically cause both **hair loss (alopecia)** and **hirsutism**, particularly in women and children. - However, phenytoin has a **stronger and more classical association** with hirsutism. - Valproate is also known for **weight gain**, **hepatotoxicity**, **pancreatitis**, and **teratogenicity**.*Carbamazepine* - Carbamazepine's common side effects include **drowsiness**, **dizziness**, **diplopia**, and **hyponatremia**. - It is not classically linked to **hirsutism** as a prominent adverse effect. - Can cause **agranulocytosis** and **Stevens-Johnson syndrome** in rare cases.*Phenobarbitone* - Phenobarbitone is an older antiepileptic drug associated with **sedation**, **cognitive impairment**, and **dependence**. - It does not commonly cause **hirsutism**. - Also causes **enzyme induction** leading to multiple drug interactions.
Question 67: What is the iodine content percentage in amiodarone?
- A. 10 - 20%
- B. 20 - 40% (Correct Answer)
- C. 40 - 60%
- D. 60 - 80%
Explanation: ***20 - 40%*** - **Amiodarone** is highly lipophilic and contains a significant amount of **iodine**, typically comprising around **37.5%** of its molecular weight. - This high iodine content is responsible for many of its **adverse effects**, particularly those related to thyroid dysfunction. *10 - 20%* - This range is too low; the actual iodine content in **amiodarone** is considerably higher, making it a prominent feature of the drug's chemical structure. - A lower iodine percentage would likely result in fewer **thyroid-related side effects**. *40 - 60%* - While amiodarone has a high iodine content, 40-60% is slightly above the generally accepted range. - Iodine constitutes a substantial but not an overwhelming majority of the drug's molecular mass. *60 - 80%* - This range is significantly higher than the actual iodine content in **amiodarone**. - Such a high percentage would imply an even greater propensity for **iodine-induced adverse effects**.
Question 68: Which of the following medications is known to cause increased renin levels with prolonged use?
- A. Clonidine
- B. Enalapril (Correct Answer)
- C. Methyldopa
- D. Propranolol
Explanation: ***Enalapril*** - **Enalapril** is an **ACE inhibitor** which blocks the conversion of angiotensin I to angiotensin II, leading to decreased levels of angiotensin II [1]. - Reduced angiotensin II levels remove the **negative feedback** on renin release from the juxtaglomerular cells, thus increasing renin secretion [1], [2]. *Clonidine* - Clonidine is a **central alpha-2 adrenergic agonist** that reduces sympathetic outflow from the central nervous system. - This reduction in sympathetic activity leads to a **decrease in renin release**, as sympathetic stimulation normally promotes renin secretion [3]. *Methyldopa* - Methyldopa is a **central alpha-2 adrenergic agonist** that works similarly to clonidine by reducing sympathetic tone. - It consequently causes a **decrease in plasma renin activity** due to reduced sympathetic stimulation of the juxtaglomerular apparatus [3]. *Propranolol* - Propranolol is a **non-selective beta-blocker** that blocks beta-1 receptors in the juxtaglomerular cells of the kidney. - This blockade **inhibits the release of renin** stimulated by sympathetic activity, leading to reduced renin levels [3].
Question 69: Which of the following is NOT caused by Prostaglandin E2 (PGE2)?
- A. None of the options (Correct Answer)
- B. Water retention
- C. Flushing
- D. Uterine contraction
Explanation: ***None of the options*** - All three listed effects (water retention, uterine contraction, and flushing) **ARE caused by Prostaglandin E2 (PGE2)**, making this the correct answer to the question asking what is NOT caused by PGE2. - Since PGE2 actually causes all the listed effects, "None of the options" is the accurate response. *Water retention* - PGE2 **stimulates ADH (vasopressin) release** from the posterior pituitary gland. - PGE2 also **enhances ADH action** on renal collecting ducts, promoting water reabsorption. - While PGE2 has complex renal effects including natriuresis, its net effect includes **promoting water retention** through the ADH mechanism. - This is an important effect of PGE2 on fluid balance. *Uterine contraction* - PGE2 is a **potent stimulator of uterine smooth muscle contraction**. - It is used clinically for **labor induction** and **cervical ripening** (dinoprostone). - PGE2 plays a crucial role in **parturition** and is involved in **dysmenorrhea**. *Flushing* - PGE2 causes **peripheral vasodilation**, particularly in cutaneous blood vessels. - This vasodilatory effect leads to **increased skin blood flow**, manifesting as **flushing** and warmth. - This is commonly seen as part of the **inflammatory response** and contributes to erythema.
Question 70: Which drug is commonly used for outpatient department (OPD) analgesia?
- A. Diclofenac
- B. Ibuprofen
- C. Paracetamol (Correct Answer)
- D. Tramadol
Explanation: ***Paracetamol*** - It is a widely used and generally **safe analgesic** and antipyretic often prescribed for mild to moderate pain in an outpatient setting. - Its favorable side effect profile and availability as an **over-the-counter (OTC)** medication make it a first-choice drug for many common pain conditions. *Diclofenac* - While it is an effective NSAID used for pain and inflammation, its use can be associated with **gastrointestinal side effects** like ulcers and bleeding, as well as cardiovascular risks. - It is often reserved for more significant inflammatory pain or when other analgesics are insufficient, and may require more careful monitoring in an outpatient setting. *Ibuprofen* - Similar to diclofenac, Ibuprofen is an **NSAID** which is effective for pain and inflammation. However, it also carries risks of **gastrointestinal irritation** and renal side effects, especially with prolonged use or in certain patient populations. - While available OTC, its use for routine outpatient analgesia may be less preferred than paracetamol in some cases due to its GI and renal side effect profile. *Tramadol* - Tramadol is a **central acting opioid analgesic** with a higher potential for side effects such as nausea, dizziness, constipation, and the risk of dependence or abuse. - It is typically reserved for moderate to severe pain that is not adequately managed by non-opioid analgesics, and its prescription often involves more stringent monitoring than paracetamol.