Which triptan is available in nasal spray form?
Acetaminophen [Paracetamol] induced liver toxicity is due to which metabolite?
Which of the following drugs is commonly used as a rescue medication for acute asthma attacks?
In primary open-angle glaucoma, pilocarpine eye drops lower intraocular pressure primarily by acting on which of the following?
From which part of the Papaver somniferum plant does the latex, commonly referred to as 'milk', exude?
Which of the following substances is commonly known as an arrow poison used by indigenous South American tribes?
In the context of pharmacology, what is the term 'Mickey Finn' commonly associated with?
Best method of treatment for methyl alcohol poisoning is:
When alcohol is consumed with aerated soft drinks -
Which of the following is not true about the Vi polysaccharide vaccine for typhoid?
NEET-PG 2015 - Pharmacology NEET-PG Practice Questions and MCQs
Question 91: Which triptan is available in nasal spray form?
- A. Sumatriptan (Correct Answer)
- B. Rizatriptan
- C. Naratriptan
- D. Frovatriptan
Explanation: ***Sumatriptan*** - **Sumatriptan** is available in multiple formulations, including **oral, subcutaneous injection, and nasal spray**, making it versatile for migraine treatment [1], [2]. - The nasal spray formulation allows for **faster absorption** and onset of action, which can be beneficial for patients with nausea or vomiting during migraine attacks [1]. *Rizatriptan* - **Rizatriptan** is primarily available in **oral tablet** and **orally disintegrating tablet** (ODT) forms [2]. - It does not have a commonly available nasal spray formulation for migraine treatment [2]. *Naratriptan* - **Naratriptan** is available as an **oral tablet** and is known for its **longer half-life** and generally milder side effect profile compared to sumatriptan [2]. - It is not available in a nasal spray formulation [2]. *Frovatriptan* - **Frovatriptan** is available exclusively as an **oral tablet** and is notable for having the **longest half-life** among triptans, making it useful for preventing recurring migraines [2]. - There is no nasal spray formulation for frovatriptan [2].
Question 92: Acetaminophen [Paracetamol] induced liver toxicity is due to which metabolite?
- A. Co-Q
- B. Cytochrome 'C'
- C. NAPQI (Correct Answer)
- D. N-acetylcysteine
Explanation: ***NAPQI*** - **N-acetyl-p-benzoquinone imine (NAPQI)** is a highly reactive and toxic metabolite produced during acetaminophen metabolism, especially in overdose situations [1, 3]. - When glutathione stores are depleted due to excessive NAPQI formation, this metabolite covalently binds to hepatic macromolecules, causing **hepatocellular damage and necrosis** [1, 3].*N-acetylcysteine* - **N-acetylcysteine (NAC)** is the antidote for acetaminophen overdose, not the toxic metabolite itself [2, 3]. - NAC works by replenishing hepatic **glutathione stores**, which helps detoxify NAPQI and prevent liver injury [2, 3].*Co-Q* - **Coenzyme Q10 (CoQ10)** is an endogenous antioxidant and electron carrier in the mitochondrial respiratory chain. - It is not a metabolite of acetaminophen and plays no direct role in acetaminophen-induced liver toxicity.*Cytochrome 'C'* - **Cytochrome c** is a protein involved in the electron transport chain in mitochondria and plays a critical role in apoptosis. - While cellular damage from NAPQI can eventually lead to cytochrome c release and apoptosis, cytochrome c itself is not a metabolite of acetaminophen or the direct cause of toxicity.
Question 93: Which of the following drugs is commonly used as a rescue medication for acute asthma attacks?
- A. Salbutamol (Correct Answer)
- B. Theophylline
- C. Terbutaline
- D. Budesonide
Explanation: ***Salbutamol*** - **Salbutamol** (albuterol) is a **short-acting beta-2 agonist (SABA)** that rapidly relaxes bronchial smooth muscle. - Its quick onset of action makes it ideal for immediate relief of **bronchoconstriction** during an acute asthma attack. - It is the **most commonly used** and **first-line rescue medication** for acute asthma worldwide. *Terbutaline* - **Terbutaline** is also a **short-acting beta-2 agonist (SABA)** similar to salbutamol and can be used as a rescue medication. - While it has comparable bronchodilator effects, **salbutamol is more commonly used** as the preferred rescue inhaler in clinical practice. - Both are SABAs, but salbutamol has become the standard first-choice rescue medication globally. *Theophylline* - **Theophylline** is a **methylxanthine** that acts as a bronchodilator but has a **narrow therapeutic index** and slower onset of action. - It is used as a **maintenance therapy** for chronic asthma and not as a rescue drug for acute exacerbations. *Budesonide* - **Budesonide** is an **inhaled corticosteroid (ICS)** used as a **long-term controller medication** to reduce airway inflammation. - It has a slow onset of action and is *not* effective for immediate relief during an acute asthma attack.
Question 94: In primary open-angle glaucoma, pilocarpine eye drops lower intraocular pressure primarily by acting on which of the following?
- A. All of the options
- B. Trabecular meshwork
- C. Ciliary epithelium
- D. Longitudinal fibres of the ciliary muscle (Correct Answer)
Explanation: ***Longitudinal fibres of the ciliary muscle***- Pilocarpine is a **muscarinic agonist** that contracts the **longitudinal fibers of the ciliary muscle** [1, 3].- This contraction pulls on the **scleral spur**, separating the **trabecular meshwork** sheets, which increases conventional **aqueous humor outflow** [2, 3].*Trabecular meshwork*- While the **trabecular meshwork** is the site where aqueous humor exits the eye, pilocarpine primarily acts on the ciliary muscle to **indirectly affect** the meshwork's outflow facility [2, 3].- Pilocarpine does not directly alter the structure or function of the trabecular meshwork cells.*Ciliary epithelium*- The **ciliary epithelium** is responsible for **aqueous humor production** [1, 2].- Pilocarpine primarily affects **outflow**, not production, through its action on the ciliary muscle [1, 2].*All of the options*- Pilocarpine does not act on **all** these structures; its primary mechanism is through the ciliary muscle to enhance outflow.- It has no direct significant effect on **ciliary epithelium** or direct action on the **trabecular meshwork** itself.
Question 95: From which part of the Papaver somniferum plant does the latex, commonly referred to as 'milk', exude?
- A. Leaf of the plant
- B. Root of the plant
- C. Seeds of the plant
- D. Unripe capsule of the plant (Correct Answer)
Explanation: ***Unripe capsule of the plant*** - The **latex** (or 'milk') containing **opioid alkaloids** like morphine and codeine is primarily harvested by incising the **unripe seed capsules** of the *Papaver somniferum* plant. - This milky sap is then collected and dried to produce **crude opium**. *Leaf of the plant* - The leaves of *Papaver somniferum* do not contain significant amounts of the latex and are not the primary source of **opium alkaloids**. - While some **alkaloids** might be present in trace amounts, they are not extracted commercially from the leaves. *Root of the plant* - The roots of the poppy plant are not known to exude latex or to be a significant source of medically relevant **opioid alkaloids**. - Their primary function is absorption of water and nutrients, and anchoring the plant. *Seeds of the plant* - While the dried seeds are used for culinary purposes (poppy seeds), they contain very low levels of **opioid alkaloids** compared to the latex. - The latex is produced within the **capsule** before the seeds fully mature.
Question 96: Which of the following substances is commonly known as an arrow poison used by indigenous South American tribes?
- A. Opium
- B. Curare (Correct Answer)
- C. Cannabis
- D. Cyanide
Explanation: ***Curare*** - **Curare** is the traditional name for South American arrow poisons derived from plants, primarily *Chondrodendron tomentosum* and *Strychnos* species - It acts as a **competitive non-depolarizing neuromuscular blocking agent**, blocking nicotinic receptors at the neuromuscular junction - Causes **skeletal muscle paralysis** by competing with acetylcholine, leading to respiratory failure in prey - **Clinical relevance:** Tubocurarine (d-tubocurarine), derived from curare, was historically used as a muscle relaxant in surgery; modern derivatives include atracurium, vecuronium, and rocuronium *Opium* - **Opium** is derived from *Papaver somniferum* (opium poppy) and contains alkaloids like morphine and codeine - Acts on **opioid receptors** in the CNS to produce analgesia and sedation - Not used as an arrow poison by South American tribes; its effects are analgesic rather than paralytic *Cannabis* - **Cannabis** (*Cannabis sativa*) contains psychoactive compounds like THC (tetrahydrocannabinol) - Acts on **cannabinoid receptors** producing psychoactive and analgesic effects - Not used as an arrow poison; lacks the rapid paralytic action needed for hunting *Cyanide* - **Cyanide** inhibits cytochrome c oxidase, blocking cellular respiration and causing rapid cell death - While highly toxic, it is **not the traditional arrow poison** of South American indigenous tribes - Traditional arrow poisons like curare cause neuromuscular paralysis rather than cellular asphyxiation
Question 97: In the context of pharmacology, what is the term 'Mickey Finn' commonly associated with?
- A. Chloroform
- B. Methyl alcohol
- C. Chloral hydrate (Correct Answer)
- D. Ethylene glycol
Explanation: ***Chloral hydrate*** - A "Mickey Finn" is a slang term for a drink **laced with a psychoactive drug or incapacitating agent** given to an unsuspecting person. - Historically, **chloral hydrate** was a common substance used for this purpose due to its rapid sedative-hypnotic effects. *Chloroform* - While chloroform is a potent anesthetic and sedative, it is primarily used as an **inhalant** and is not typically administered orally in drinks. - Ingesting chloroform in large quantities can be **fatal due to severe hepatotoxicity and neurotoxicity**. *Methyl alcohol* - **Methyl alcohol (methanol)** is highly toxic and causes severe metabolic acidosis, blindness, and death, even in small amounts. - It does not induce the quick, incapacitating sedative effects associated with a "Mickey Finn" but rather a **delayed, severe poisoning syndrome**. *Ethylene glycol* - **Ethylene glycol** is an antifreeze agent that is also highly toxic, causing kidney failure and metabolic derangements. - Similar to methanol, its effects are **delayed and severe**, not the immediate incapacitating sedation implied by the term "Mickey Finn."
Question 98: Best method of treatment for methyl alcohol poisoning is:
- A. Calcium gluconate
- B. Ethyl alcohol (Correct Answer)
- C. Amphetamines
- D. 1% Ammonia
Explanation: ***Ethyl alcohol*** - **Ethanol** (ethyl alcohol) acts as a competitive substrate for **alcohol dehydrogenase**, the enzyme responsible for metabolizing **methanol** into toxic metabolites like formaldehyde and formic acid. - By saturating alcohol dehydrogenase, ethanol prevents the formation of these toxic metabolites, allowing methanol to be excreted unchanged. - **Clinical note**: While **fomepizole** (4-methylpyrazole) is now the preferred first-line antidote when available, **ethanol** remains an effective and widely used alternative, especially in resource-limited settings. - **Administration**: IV ethanol is given to maintain blood ethanol concentration of 100-150 mg/dL. *Calcium gluconate* - **Calcium gluconate** is primarily used to treat **hypocalcemia**, ethylene glycol poisoning (for hypocalcemia), or hydrofluoric acid burns. - It has no role in the management of methyl alcohol poisoning as it does not interfere with the metabolism of methanol or its toxic byproducts. *Amphetamines* - **Amphetamines** are central nervous system stimulants used for conditions like ADHD and narcolepsy. - They have no therapeutic benefit or antidotal properties in the context of methanol poisoning. *1% Ammonia* - **Ammonia** is a strong base and is highly corrosive; it has no medical application as an antidote for methanol poisoning. - Administering ammonia would cause direct tissue damage and exacerbate patient harm due to its toxic and caustic properties.
Question 99: When alcohol is consumed with aerated soft drinks -
- A. Effect is enhanced
- B. To reduce hangover risk
- C. Absorption is faster, increasing intoxication risk (Correct Answer)
- D. None of the options
Explanation: ***Absorption is faster, increasing intoxication risk*** - The carbonation in aerated soft drinks speeds up the absorption of alcohol into the bloodstream. - This **faster absorption** leads to a more rapid increase in blood alcohol concentration and can intensify the effects of alcohol, thereby increasing the risk of intoxication. *Effect is enhanced* - While the **effect** might seem to be enhanced due to quicker onset, this option doesn't fully explain the physiological mechanism. - The primary reason for the perceived enhancement is the **accelerated absorption**, not a direct potentiation of alcohol's action. *To reduce hangover risk* - Mixing alcohol with aerated drinks generally **does not reduce hangover risk**; in fact, the rapid absorption can sometimes worsen dehydration and lead to a more severe hangover. - Hangovers are primarily caused by dehydration, acetaldehyde buildup, and other congeners, which are not mitigated by carbonated mixers. *None of the options* - This option is incorrect because the statement about **faster absorption leading to increased intoxication risk** is a well-established physiological effect.
Question 100: Which of the following is not true about the Vi polysaccharide vaccine for typhoid?
- A. Given intramuscularly
- B. Given at birth (Correct Answer)
- C. Revaccination at 3 years
- D. Single dose is given
Explanation: ***Given at birth*** - The **typhoid Vi polysaccharide vaccine is not administered at birth**. It is recommended for individuals **2 years of age**. - Vaccines given at birth protect against diseases with significant **neonatal risk**, such as Hepatitis B and BCG (tuberculosis). - This is the **FALSE** statement, making it the correct answer to this "not true" question. *Single dose is given* - The Vi polysaccharide vaccine is administered as a **single 0.5 mL dose**. - This single dose provides protection against *Salmonella typhi* for approximately 3 years. - This statement is **TRUE**. *Revaccination at 3 years* - For ongoing protection, **revaccination is recommended every 3 years** for individuals at continued risk of typhoid exposure. - The booster dose maintains adequate protective antibody levels. - This statement is **TRUE**. *Given intramuscularly* - The Vi polysaccharide vaccine is administered via the **intramuscular (IM) route**, typically in the deltoid muscle. - This is the standard recommended route of administration. - This statement is **TRUE**.