General Pharmacology Practice Questions

Q: What is the recommended dose regimen of Vitamin A for the treatment of early stages of Xerophthalmia?

2 lac IU on two successive days. ***2 lac IU on two successive days*** - The **WHO-recommended treatment protocol** for xerophthalmia (including early stages) involves a **3-dose regimen**: 200,000 IU immediately, followed by 200,000 IU the next day, and a third dose at least 2 weeks later. - The **first two doses on consecutive days** represent the critical initial treatment phase to rapidly replenish vitamin A stores and prevent progression to sight-threatening corneal damage. - This regimen applies to children **12 months and older and adults**; infants under 12 months receive 100,000 IU doses. *Single massive dose of 2 lac International Units (IU)* - While a high dose is essential, **a single dose alone is insufficient** for treating xerophthalmia according to WHO guidelines. - The second dose on the consecutive day is critical to ensure adequate tissue saturation and prevent progression of corneal lesions. - Single-dose regimens are used for **prophylaxis in high-risk populations**, not for active treatment of xerophthalmia. *2 doses of 1 lac IU at a gap of one week* - **100,000 IU doses** are recommended for **infants under 12 months of age**, not for older children and adults with xerophthalmia. - The one-week interval does not match the WHO protocol, which requires the second dose on the **very next day** to ensure rapid correction. *2 doses of 1 lac IU in two successive days* - This dosing regimen is appropriate for **infants aged 6-12 months** with xerophthalmia, where each dose is 100,000 IU. - For children **12 months and older and adults**, the standard dose is **200,000 IU (2 lac IU)**, making this dosage insufficient for the typical patient population.

Q: Which of the following is false about the selection of essential drugs?

Fixed drug combination is preferred over single drugs. ***Fixed drug combination is preferred over single drugs*** - The statement that **fixed-drug combinations (FDCs)** are preferred over single drugs for essential drug selection is false. Generally, **single drugs are preferred** to allow for individual dose adjustments and minimize potential adverse effects from unnecessary components. - FDCs are only considered essential when they offer specific advantages, such as **improved adherence** (e.g., in tuberculosis treatment) or a **synergistic effect** not achievable with individual drugs. *Cost to benefit has to be considered* - This statement is true; the **cost-effectiveness** and **cost-benefit ratio** are crucial factors in selecting essential drugs. - Essential drugs aim to provide the most public health benefit at an **affordable cost**, ensuring access for a broad population. *An adequate safety profile needs to be established* - This statement is true; essential drugs must have a **well-established safety profile** with acceptable risks. - The benefits of the drug must significantly outweigh its potential harms, with minimal serious **adverse reactions**. *Disease prevalence is considered* - This statement is true; essential drugs are selected based on their ability to address the **most prevalent diseases** and health needs of a population. - Prioritizing drugs for common conditions ensures that public health resources are effectively allocated to where they are most needed.

Q: Which of the following is the shortest-acting corticosteroid?

Hydrocortisone. ***Hydrocortisone***- **Hydrocortisone** is considered a **short-acting corticosteroid** with a biological half-life of 8-12 hours [1].- It is a naturally occurring glucocorticoid, acting as a direct replacement for cortisol.- Among the given options, it has the shortest duration of action.*Dexamethasone*- **Dexamethasone** is a **long-acting corticosteroid** with a biological half-life of 36-72 hours.- Its potent and prolonged action makes it suitable for conditions requiring sustained anti-inflammatory or immunosuppressive effects.*Triamcinolone*- **Triamcinolone** is an **intermediate-acting corticosteroid** with a biological half-life typically ranging from 18-36 hours.- It is commonly used for its anti-inflammatory effects in conditions like allergies, asthma, and skin disorders.*Deflazacort*- **Deflazacort** is an **intermediate-acting corticosteroid** with a duration of action of approximately 12-18 hours.- It is a prodrug that is metabolized to 21-desacetyl deflazacort, the active form, often used in conditions like Duchenne muscular dystrophy and inflammatory disorders.

Q: Which fluoride compound is most effective for bacterial enzyme inhibition after topical application:

SnF2. ***Correct: SnF2 (Stannous Fluoride)*** - **Stannous fluoride (SnF2)** is the most effective fluoride compound for **bacterial enzyme inhibition** after topical application - Provides **dual antimicrobial mechanism**: fluoride ions inhibit enolase in glycolysis, while stannous ions (Sn²⁺) have **direct bactericidal effects** and inhibit multiple bacterial enzymes - The **stannous ion** penetrates bacterial cell walls and disrupts enzyme systems more effectively than fluoride alone - Superior at inhibiting **acid production** by cariogenic bacteria through enhanced enzyme interference - Clinically proven **anti-plaque** and **antimicrobial** properties beyond simple fluoride action *Incorrect: NaF (Sodium Fluoride)* - While NaF releases fluoride ions that inhibit bacterial enolase, it lacks the additional antimicrobial activity of the stannous ion - Its primary mechanism is **remineralization** of enamel through fluorapatite formation, not superior bacterial enzyme inhibition - Less effective than SnF2 for direct antibacterial enzyme inhibition *Incorrect: Sodium mono-fluorophosphate* - Requires **enzymatic hydrolysis** by bacterial or salivary phosphatases to release free fluoride ions - This delayed release makes it **less effective** for immediate bacterial enzyme inhibition - Preferred in toothpastes for chemical stability, not for antimicrobial efficacy *Incorrect: APF (Acidulated Phosphate Fluoride)* - Low pH enhances **fluoride uptake into enamel** for remineralization - Primary advantage is **fluorapatite formation** and enamel strengthening - Not specifically superior for bacterial enzyme inhibition compared to SnF2's dual-action mechanism

Q: Influenza vaccines are administered via:

Intranasal spray. ***Intranasal spray*** * The **live attenuated influenza vaccine (LAIV)** is administered via **intranasal spray**, making it a needle-free option suitable for healthy individuals aged 2-49 years. * This route allows the vaccine to mimic natural infection in the respiratory tract, potentially inducing both systemic and mucosal immunity. *Intramuscularly* * The **inactivated influenza vaccine (IIV)**, or "flu shot," is the **most commonly used** form and is administered **intramuscularly**. * This involves injecting the vaccine into the deltoid muscle in adults or the anterolateral thigh in infants and young children. * Both intramuscular and intranasal routes are valid for influenza vaccination depending on vaccine type and patient eligibility. *Intradermal* * While **intradermal influenza vaccines** have been developed and approved (e.g., Fluzone Intradermal), they are **less commonly used** than IM vaccines. * This route involves injecting the vaccine into the dermis using a microinjection system. * Not the primary route for standard influenza vaccination programs. *Intrathecal* * **Intrathecal administration** involves injecting medication directly into the **cerebrospinal fluid** surrounding the spinal cord. * This route is used for specific neurological conditions or chemotherapy and is **entirely inappropriate and dangerous** for vaccine delivery.

Q: Transdermal patch is not used for the following drug?

Naloxone. Naloxone - **Naloxone** is an **opioid antagonist** primarily used for the emergency reversal of opioid overdose, requiring a rapid onset of action [3]. - Its therapeutic goal is immediate, high systemic concentrations, which is not suitable for the slow, sustained release characteristic of a transdermal patch. *GTN* - **Glyceryl trinitrate (GTN)** is used in a transdermal patch for the **prophylaxis of angina**, providing a sustained release [1]. - This allows for consistent vasodilation and reduction of cardiac workload over an extended period [1]. *Fentanyl* - **Fentanyl** transdermal patches are commonly used for the management of **chronic severe pain**, particularly in opioid-tolerant patients [2]. - The patch provides continuous systemic delivery of the potent opioid, offering long-lasting pain relief [2]. *Nicotine* - **Nicotine** patches are widely used as **nicotine replacement therapy (NRT)** to aid in smoking cessation. - They deliver a steady dose of nicotine transdermally, reducing withdrawal symptoms and cravings.

Q: 1 ml of 7.5% sodium bicarbonate provides:-

0.9 meq bicarbonate. ***0.9 meq bicarbonate*** - A 7.5% solution means 7.5 grams of sodium bicarbonate in 100 ml of solution. Thus, 1 ml contains **0.075 grams** (75 mg). - The molecular weight of sodium bicarbonate (NaHCO₃) is approximately **84 g/mol**. Since it is a monovalent ion, 1 mmol equals 1 mEq. Therefore, 75 mg is approximately **0.892 mEq**, which rounds to 0.9 mEq. *0.5 meq bicarbonate* - This value is significantly **lower** than the actual amount of bicarbonate contained in 1 ml of a 7.5% solution. - An error in calculation, such as an incorrect molecular weight or percentage conversion, would lead to this underestimation. *1.5 meq bicarbonate* - This value is **higher** than the actual amount of bicarbonate and would be closer to the concentration of a 12.5% solution or a significantly larger volume. - This suggests a **miscalculation** of the concentration or the amount present in 1 ml. *1.1 meq bicarbonate* - While closer than other incorrect options, this value is still an **overestimation**. - A slight error in the molecular weight used for calculation or in the initial mass conversion could lead to this result.

Q: Which of the following is a true statement about routes of drug administration?

100% bioavailability is seen in case of IV route.. ***100% bioavailability is seen in case of IV route.*** - **Intravenous administration** achieves **100% bioavailability** by definition as the drug is delivered directly into the **systemic circulation**, bypassing all absorption barriers. - This route eliminates **first-pass metabolism** and absorption variability, ensuring complete drug availability for therapeutic action. *sterile technique is needed in case of I.V. and I.M. administration.* - While this statement is correct, it is **incomplete** as sterile technique is required for **all parenteral routes** including subcutaneous, intradermal, and intrathecal administrations. - The statement fails to acknowledge that **aseptic technique** is a fundamental requirement for any route that bypasses natural body barriers. *Irritation and local tissue necrosis can be seen in case of unsuitable routes like intramuscular or subcutaneous route.* - **Tissue necrosis** is an extreme complication that occurs only with highly **caustic substances** or severe injection errors, not a general characteristic of IM or SC routes. - Most drugs are **well-tolerated** via IM and SC routes when administered properly with appropriate formulations. *In the inhalational route, absorption of drugs takes place from vast surfaces of alveoli - so bioavailability is high and action is very rapid.* - While **rapid onset** is correct due to the large **alveolar surface area** (50-100 m²), bioavailability via inhalation is **variable** (typically 10-60%). - Bioavailability depends on **particle size**, inhalation technique, and drug formulation, making it less predictable than stated.

Q: The following smooth muscle relaxants act by affecting calcium release except:

Prazosin. ***Prazosin*** - Prazosin is an **alpha-1 adrenergic receptor antagonist** that causes smooth muscle relaxation by blocking the vasoconstrictive effects of norepinephrine, **not by directly affecting calcium release or calcium channels** [4]. - Its mechanism involves preventing receptor-mediated vasoconstriction through downstream signaling pathways, which are distinct from direct calcium channel modulation or calcium release from intracellular stores. - **This is the correct answer** as it does not act by affecting calcium handling. *Dantrolene* - Dantrolene acts by inhibiting the release of **calcium from the sarcoplasmic reticulum** in muscle cells by blocking **ryanodine receptors (RyR1)**. - **Important note:** Dantrolene is primarily a **skeletal muscle relaxant** used for malignant hyperthermia and spasticity, not a typical smooth muscle relaxant. - While it does affect calcium release, its primary therapeutic action is on skeletal muscle, making its inclusion in "smooth muscle relaxants" questionable. *Nifedipine* - Nifedipine is a **dihydropyridine calcium channel blocker** that inhibits the influx of extracellular calcium into smooth muscle cells [2]. - By blocking **L-type voltage-gated calcium channels**, it reduces intracellular calcium availability, leading to smooth muscle relaxation, particularly in vascular smooth muscle [1], [3]. *Verapamil* - Verapamil is a **non-dihydropyridine calcium channel blocker** that also inhibits the influx of extracellular calcium into smooth muscle cells [3]. - It primarily affects **L-type calcium channels** in both cardiac and smooth muscle, leading to vasodilation and reduced cardiac contractility [1], [2].

Question 1

What is the recommended dose regimen of Vitamin A for the treatment of early stages of Xerophthalmia?

Accepted Answer

2 lac IU on two successive days

Answer

Single massive dose of 2 lac International Units (IU)

Answer

2 doses of 1 lac IU at a gap of one week

Answer

2 doses of 1 lac IU in two successive days

Question 2

Which of the following is false about the selection of essential drugs?

Accepted Answer

Fixed drug combination is preferred over single drugs

Answer

Cost to benefit has to be considered

Answer

An adequate safety profile needs to be established

Answer

Disease prevalence is considered

Question 3

Which of the following is the shortest-acting corticosteroid?

Accepted Answer

Hydrocortisone

Answer

Dexamethasone

Answer

Triamcinolone

Answer

Deflazacort

Question 4

Which fluoride compound is most effective for bacterial enzyme inhibition after topical application:

Accepted Answer

SnF2

Answer

NaF

Answer

APF

Answer

Sodium mono-fluorophosphate

Question 5

Influenza vaccines are administered via:

Accepted Answer

Intranasal spray

Answer

Intradermal

Answer

Intrathecal

Answer

Intramuscularly

Question 6

Transdermal patch is not used for the following drug?

Accepted Answer

Naloxone

Answer

GTN

Answer

Fentanyl

Answer

Nicotine

Question 7

1 ml of 7.5% sodium bicarbonate provides:-

Accepted Answer

0.9 meq bicarbonate

Answer

0.5 meq bicarbonate

Answer

1.5 meq bicarbonate

Answer

1.1 meq bicarbonate

Question 8

Which of the following is a true statement about routes of drug administration?

Accepted Answer

100% bioavailability is seen in case of IV route.

Answer

In the inhalational route, absorption of drugs takes place from vast surfaces of alveoli - so bioavailability is high and action is very rapid.

Answer

Irritation and local tissue necrosis can be seen in case of unsuitable routes like intramuscular or subcutaneous route.

Answer

sterile technique is needed in case of I.V. and I.M. administration.

Question 9

The following smooth muscle relaxants act by affecting calcium release except:

Accepted Answer

Prazosin

Answer

Dantrolene

Answer

Nifedipine

Answer

Verapamil

Question 10

Which of the following statements best describes an orphan drug?

Accepted Answer

It is a drug declared for treatment or prevention of a rare disease

Answer

It is a drug which has no therapeutic use

Answer

It is a very cheap drug

Answer

It is a drug which acts on orphan receptors

General Pharmacology — MCQs

General Pharmacology — MCQs

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