Clinical Pharmacology and Drug Toxicity Practice Questions

Q: Absolute contraindication to combined oral contraceptive is:

History of thrombo-embolism. ***History of thrombo-embolism*** - A history of **thromboembolism** (e.g., DVT, pulmonary embolism) is an **absolute contraindication** to combined oral contraceptives (COCs) due to the increased risk of further thrombotic events associated with estrogen. - COCs, particularly their estrogen component, can increase levels of clotting factors and decrease natural anticoagulants, significantly raising the risk of **venous thromboembolism (VTE)**. *History of gallbladder disease* - A history of **gallbladder disease** is generally considered a **relative contraindication** rather than an absolute one for COCs. - While COCs may exacerbate pre-existing gallbladder conditions or increase the risk of gallstone formation in some individuals, it doesn't preclude their use in all cases. *History of GDM* - A history of **gestational diabetes mellitus (GDM)** is a **relative contraindication** or caution for COC use, particularly in women with additional risk factors for diabetes. - While COCs can affect glucose tolerance, they are not absolutely contraindicated unless the woman has developed overt diabetes or has poorly controlled metabolic issues. *History of previous two caesarean section* - A history of previous **two cesarean sections** is **not a contraindication** to combined oral contraceptive use. - This obstetric history does not impact the metabolic or thrombotic risks associated with COCs, and thus, does not directly interact with their safety profile.

Q: Match List-I with List-II and select the correct answer using the code given below the Lists:

A→4 B→3 C→2 D→1. ***A→4 B→3 C→2 D→1*** - This option correctly matches **Stomach poison** with **Sodium fluoride** (4), **Organochlorine compound** with **Dieldrin** (3), **Organophosphorus compound** with **Temephos** (2), and **Carbamates** with **Propoxur** (1). - **Sodium fluoride** acts as a stomach poison requiring ingestion, **Dieldrin** is a persistent organochlorine insecticide, **Temephos** is an organophosphorus compound used for larval control, and **Propoxur** is a carbamate insecticide for household pest control. *A→4 B→3 C→1 D→2* - This option incorrectly matches **Organophosphorus compound** with **Propoxur** (1), which is actually a **carbamate**, not an organophosphorus compound. - It also incorrectly matches **Carbamates** with **Temephos** (2), which is actually an **organophosphorus** compound, not a carbamate. *A→3 B→4 C→2 D→1* - This option incorrectly matches **Stomach poison** with **Dieldrin** (3), which is an **organochlorine compound**, not a stomach poison. - It also incorrectly matches **Organochlorine compound** with **Sodium fluoride** (4), which functions as a **stomach poison**, not an organochlorine compound. *A→3 B→4 C→1 D→2* - This option creates multiple incorrect matches: **Stomach poison** with **Dieldrin** (3) instead of **Sodium fluoride**, and **Organochlorine compound** with **Sodium fluoride** (4) instead of **Dieldrin**. - It also incorrectly swaps the organophosphorus and carbamate matches, placing **Propoxur** with organophosphorus and **Temephos** with carbamates.

Q: Which one of the following antihypertensive drugs is NOT safe during pregnancy?

ACE-inhibitors. ***ACE-inhibitors*** - **ACE inhibitors** (e.g., enalapril, lisinopril) are **contraindicated** in pregnancy due to their association with severe fetal abnormalities, including **renal agenesis**, **oligohydramnios**, and **fetal death** [1], [2]. - They should be discontinued as soon as pregnancy is confirmed or suspected due to their known **teratogenic effects** [1], [2].*Labetalol* - **Labetalol**, a combined alpha- and beta-blocker, is considered one of the **first-line agents** for managing hypertension in pregnancy. - It has a good safety profile for both the mother and the fetus and is commonly used in conditions like **preeclampsia**.*Nifedipine* - **Nifedipine**, a calcium channel blocker, is also a **safe and effective** option for treating hypertension during pregnancy. - It is frequently used for managing **chronic hypertension** and **preeclampsia** due to its rapid onset of action and tolerability.*Alpha-methyl dopa* - **Alpha-methyl dopa** (methyldopa) is considered one of the **safest and most extensively studied** antihypertensive medications for use in pregnancy. - It is often the **first-choice agent** for chronic hypertension during pregnancy due to its long-standing track record of safety for the fetus.

Q: A patient has been diagnosed with Primary Open Angle Glaucoma (POAG). On eliciting history, it is observed that the patient is a known case of bronchial asthma. What is the drug of choice for POAG in this patient?

Latanoprost. ***Latanoprost*** - **Latanoprost** is a **prostaglandin analog** and is considered a **first-line drug of choice** for POAG due to its excellent efficacy and tolerability profile, especially in patients with **bronchial asthma**. - It works by increasing the **uveoscleral outflow** of aqueous humor, thus lowering **intraocular pressure** without causing systemic effects like bronchoconstriction. *Gemeprost* - **Gemeprost** is a **prostaglandin E1 analog** primarily used for **cervical ripening** and **abortion**, not for glaucoma treatment. - It has no role in managing **intraocular pressure** and would be an inappropriate choice for POAG. *Alprostadil* - **Alprostadil** is another **prostaglandin E1 analog** used for **erectile dysfunction** and maintaining **patency of the ductus arteriosus** in neonates. - It does not lower **intraocular pressure** and is not indicated for the treatment of glaucoma. *Carboprost* - **Carboprost** is a **prostaglandin F2α analog** mainly used to **manage postpartum hemorrhage** due to its potent uterotonic effects. - While it is a prostaglandin, it is not used in the treatment of glaucoma and has significant systemic side effects.

Q: A man was brought to the emergency room after poisoning with an unknown substance. Muscarinic poisoning was suspected and he was treated for the same. What is the possible presenting feature which led to the diagnosis?

Bradycardia. ***Bradycardia*** - Muscarinic poisoning stimulates **parasympathetic nervous system** activity, leading to a decrease in heart rate. - This **bradycardia** is a classic sign of excessive muscarinic receptor activation, as seen with organophosphate or carbamate poisoning [1, 2].*Diuresis* - While muscarinic receptor activation can increase bladder detrusor contraction (leading to urinary urgency and frequency) [1, 2], **diuresis** (increased urine production) is not a primary or direct presenting feature of muscarinic poisoning. - Instead, the focus is on incontinence rather than simply increased urine output.*Mydriasis* - **Mydriasis** (pupil dilation) is associated with **anticholinergic poisoning**, which blocks muscarinic receptors. - Muscarinic poisoning, conversely, causes **miosis** (pupil constriction) due to excessive stimulation of muscarinic receptors in the iris sphincter muscle.*Muscle fasciculations* - **Muscle fasciculations** are a characteristic sign of **nicotinic receptor overstimulation**, not muscarinic [1, 3]. - While both nicotinic and muscarinic receptors are activated in organophosphate poisoning, fasciculations point to the **nicotinic effects** at the neuromuscular junction [1, 3].

Q: Match the following drugs in Column A with their contraindications in Column B. | Column A | Column B | | :-- | :-- | | 1. Morphine | 1. QT prolongation | | 2. Amiodarone | 2. Thromboembolism | | 3. Vigabatrin | 3. Pregnancy | | 4. Estrogen preparations | 4. Head injury |

A-4, B-1, C-3, D-2. ***A-4, B-1, C-3, D-2*** - **Morphine** is contraindicated in **head injury** as it can increase intracranial pressure and mask neurological symptoms. - **Amiodarone** is contraindicated in patients with **QT prolongation** due to its risk of inducing more severe arrhythmias like Torsades de Pointes. - **Vigabatrin** is contraindicated during **pregnancy** due to its potential for teratogenicity and adverse effects on fetal development. - **Estrogen preparations** are contraindicated in patients with a history of **thromboembolism** due to their increased risk of blood clot formation. *A-1, B-3, C-2, D-4* - This option incorrectly matches **Morphine** with QT prolongation and **Estrogen preparations** with head injury, which are not their primary contraindications. - It also incorrectly links **Vigabatrin** with thromboembolism and **Amiodarone** with pregnancy. *A-3, B-2, C-4, D-1* - This choice incorrectly associates **Morphine** with pregnancy and **Vigabatrin** with head injury, which are not the most critical or direct contraindications. - It also misaligns **Amiodarone** with thromboembolism and **Estrogen preparations** with QT prolongation. *A-2, B-4, C-1, D-3* - This option incorrectly matches **Morphine** with thromboembolism and **Amiodarone** with head injury, which are not their most significant contraindications. - It also incorrectly links **Vigabatrin** with QT prolongation and **Estrogen preparations** with pregnancy.

Q: A patient presented with dizziness, cool clammy skin, pinpoint pupil with blue lips and fingernails suffering from respiratory depression. The patient was producing a pink frothy sputum on coughing. The drug used to reverse the effects is?

Naloxone. ***Naloxone*** - This patient's presentation with **pinpoint pupils**, **respiratory depression**, and **pink frothy sputum** is highly suggestive of **opioid overdose**. - **Naloxone** is a competitive opioid receptor antagonist used specifically to reverse the effects of opioid-induced respiratory depression and central nervous system depression. *Atropine* - **Atropine** is an anticholinergic drug used to treat **bradycardia** and **organophosphate poisoning**. - It would worsen opioid-induced respiratory depression and is not indicated for this presentation. *Physostigmine* - **Physostigmine** is a cholinesterase inhibitor used to reverse the effects of anticholinergic toxicity, such as from **tricyclic antidepressants** or **atropine overdose**. - It would not treat opioid toxicity and could exacerbate some symptoms. *Phentolamine* - **Phentolamine** is an **alpha-adrenergic blocker** primarily used to treat hypertensive crises, particularly those due to **pheochromocytoma** or in extravasation of vasopressors. - It has no role in the management of opioid overdose.

Q: A child went to temple along with his grandmother. He developed altered sensorium, BP of $150 / 90 \mathrm{~mm} \mathrm{Hg}$, sweating, palpitations, priapism, and mouth secretion all at once. What drug can be given to this patient?

Prazosin. ***Prazosin*** * This patient's symptoms (altered sensorium, **hypertension**, sweating, palpitations, **priapism**, and increased mouth secretions) are highly suggestive of **scorpion venom poisoning**, specifically from the Indian red scorpion (*Mesobuthus tamulus*). * **Prazosin**, an **alpha-1 adrenergic receptor blocker**, is the drug of choice for treating systemic manifestations of scorpion envenomation. It helps to counteract the excessive catecholamine release and the resulting sympathetic overdrive, thereby reducing hypertension and cardiac dysfunction. *Steroid* * Steroids are **anti-inflammatory agents** and immunosuppressants, primarily used in conditions like allergic reactions, asthma, or autoimmune diseases. * They are **not indicated** for the acute management of venom-induced symptoms such as those seen in scorpion envenomation. *Adrenaline* * **Adrenaline (epinephrine)** is a potent **vasoconstrictor** and **bronchodilator**, primarily used in anaphylaxis, cardiac arrest, or severe asthma. * It would be **contraindicated** in this patient as it would further exacerbate the existing hypertension and sympathetic stimulation caused by the scorpion venom. *ASV* * **ASV (Anti-Snake Venom)** is an antiserum used to neutralize the toxins found in snake venom. * It is **ineffective** against scorpion venom and is therefore not an appropriate treatment in this scenario.

Q: A female was given morphine sulphate during labour for pain but she developed respiratory distress. Which of the following will be the correct antidote?

Naloxone. ***Naloxone*** - **Naloxone** is a pure opioid antagonist that rapidly reverses the effects of **opioid overdose** [1, 3], including **respiratory depression** [2], by competitively binding to opioid receptors [1]. - Its short half-life may necessitate repeated doses, especially with longer-acting opioids like morphine, to prevent recurrence of respiratory depression [1]. *Epinephrine* - **Epinephrine** is an adrenergic agonist used to treat **anaphylaxis** and severe allergic reactions, as it causes **vasoconstriction** and **bronchodilation**. - It is not an antidote for opioid-induced respiratory depression, which primarily results from central nervous system effects rather than allergic reactions. *Pralidoxime* - **Pralidoxime** is a **cholinesterase reactivator** used to treat poisoning by **organophosphates**, which inhibit acetylcholinesterase, leading to cholinergic crisis. - It works by restoring the function of the enzyme, thereby breaking down excess acetylcholine, and is not indicated for opioid overdose. *Atropine* - **Atropine** is an **anticholinergic agent** that blocks muscarinic acetylcholine receptors, used to treat **bradycardia** and **organophosphate poisoning**. - It would not reverse opioid-induced respiratory depression, as it primarily affects the parasympathetic nervous system and does not antagonize opioid receptor effects.

Q: A kid went to a temple with his grandmother and was constantly crying. On examination he had excruciating pain, hypertension, increased heart rate, sweating profusely, priapism and cold clammy skin. What should be the treatment given to the patient?

Phentolamine. ***Phentolamine*** - The symptoms described (hypertension, tachycardia, sweating, priapism, cold clammy skin) are indicative of an **alpha-adrenergic crisis** or **pheochromocytoma crisis**, which results from excessive release of catecholamines (e.g., norepinephrine) [1]. - **Phentolamine** is a **non-selective alpha-adrenergic antagonist** that effectively blocks the effects of excessive catecholamines, thereby reducing blood pressure and heart rate and relieving other alpha-mediated symptoms like priapism [1]. *Atropine* - **Atropine** is an **anticholinergic drug** used to treat **bradycardia** or **organophosphate poisoning**. - It would worsen the patient's condition by potentially increasing heart rate further and would not address the underlying alpha-adrenergic overstimulation. *Pralidoxime* - **Pralidoxime** is an **acetylcholinesterase reactivator** used specifically for **organophosphate poisoning**. - It works by restoring the function of acetylcholinesterase, which is inhibited by organophosphates, and is not indicated for an adrenergic crisis. *Naloxone* - **Naloxone** is an **opioid receptor antagonist** used to reverse the effects of **opioid overdose**. - This patient's symptoms are not consistent with opioid toxicity, and naloxone would have no therapeutic benefit.

Question 1

Absolute contraindication to combined oral contraceptive is:

Accepted Answer

History of thrombo-embolism

Answer

History of gallbladder disease

Answer

History of GDM

Answer

History of previous two caesarean section

Question 2

Match List-I with List-II and select the correct answer using the code given below the Lists:

Accepted Answer

A→4  B→3  C→2  D→1

Answer

A→4  B→3  C→1  D→2

Answer

A→3  B→4  C→2  D→1

Answer

A→3  B→4  C→1  D→2

Question 3

Which one of the following antihypertensive drugs is NOT safe during pregnancy?

Accepted Answer

ACE-inhibitors

Answer

Labetalol

Answer

Nifedipine

Answer

Alpha-methyl dopa

Question 4

A patient has been diagnosed with Primary Open Angle Glaucoma (POAG). On eliciting history, it is observed that the patient is a known case of bronchial asthma. What is the drug of choice for POAG in this patient?

Accepted Answer

Latanoprost

Answer

Gemeprost

Answer

Alprostadil

Answer

Carboprost

Question 5

A man was brought to the emergency room after poisoning with an unknown substance.
Muscarinic poisoning was suspected and he was treated for the same. What is the possible presenting feature which led to the diagnosis?

Accepted Answer

Bradycardia

Answer

Diuresis

Answer

Mydriasis

Answer

Muscle fasciculations

Question 6

Match the following drugs in Column A with their contraindications in Column B.

Accepted Answer

A-4, B-1, C-3, D-2

Answer

A-1, B-3, C-2, D-4

Answer

A-3, B-2, C-4, D-1

Answer

A-2, B-4, C-1, D-3

Question 7

A patient presented with dizziness, cool clammy skin, pinpoint pupil with blue lips and fingernails suffering from respiratory depression. The patient was producing a pink frothy sputum on coughing. The drug used to reverse the effects is?

Accepted Answer

Naloxone

Answer

Atropine

Answer

Physostigmine

Answer

Phentolamine

Question 8

A child went to temple along with his grandmother. He developed altered sensorium, BP of $150 / 90 \mathrm{~mm} \mathrm{Hg}$, sweating, palpitations, priapism, and mouth secretion all at once. What drug can be given to this patient?

Accepted Answer

Prazosin

Answer

Steroid

Answer

Adrenaline

Answer

ASV

Question 9

A female was given morphine sulphate during labour for pain but she developed respiratory distress. Which of the following will be the correct antidote?

Accepted Answer

Naloxone

Answer

Epinephrine

Answer

Pralidoxime

Answer

Atropine

Question 10

A kid went to a temple with his grandmother and was constantly crying. On examination he had excruciating pain, hypertension, increased heart rate, sweating profusely, priapism and cold clammy skin. What should be the treatment given to the patient?

Accepted Answer

Phentolamine

Answer

Atropine

Answer

Pralidoxime

Answer

Naloxone

Clinical Pharmacology and Drug Toxicity — MCQs

Clinical Pharmacology and Drug Toxicity — MCQs

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