General Pharmacology Practice Questions

Q: What is the mechanism of action of Basiliximab?

IL-2 receptor antagonist. ***IL-2 receptor antagonist*** - **Basiliximab** is a **monoclonal antibody** that specifically targets and blocks the **CD25 alpha subunit** of the **interleukin-2 (IL-2) receptor** on activated T lymphocytes. - By blocking IL-2 binding, it prevents **T-cell proliferation** and differentiation, thereby suppressing the immune response and preventing **organ transplant rejection**. *IL-1 receptor antagonist* - An **IL-1 receptor antagonist** (e.g., **anakinra**) blocks the action of **interleukin-1**, a potent pro-inflammatory cytokine. - This mechanism is primarily used in inflammatory conditions like **rheumatoid arthritis** and CAPS, not directly for transplant immunosuppression in the same manner as Basiliximab. *Anti-CD3 antibody* - **Anti-CD3 antibodies** (e.g., **muromonab-CD3**) bind to the **CD3 complex** on the surface of T lymphocytes, leading to their depletion or functional inactivation. - While also used for **immunosuppression** in transplant, their mechanism of action and side effect profile are distinct from Basiliximab. *TNF inhibitor* - **TNF inhibitors** (e.g., **infliximab**, **etanercept**) block the activity of **tumor necrosis factor-alpha**, another major pro-inflammatory cytokine. - These agents are primarily used in **autoimmune diseases** such as rheumatoid arthritis, Crohn's disease, and psoriasis, not as a primary immunosuppressant for organ transplantation in the way Basiliximab is used.

Q: Which of the following is a long-acting local anesthetic?

Dibucaine. ***Dibucaine*** - **Dibucaine** is a **long-acting amide local anesthetic** with a duration of action up to 10 hours. - Its high **lipid solubility** contributes to its prolonged effect and greater potency compared to other local anesthetics. *Prilocaine* - **Prilocaine** is considered an **intermediate-duration amide local anesthetic**, with a duration of action typically 1-2 hours. - It carries a risk of **methemoglobinemia** at higher doses, which differentiates it from longer-acting agents. *Procaine* - **Procaine** is a **short-acting ester local anesthetic**, with a duration of action usually less than 1 hour. - It is known for its relatively **high allergenicity** due to its metabolism to para-aminobenzoic acid (PABA). *Lignocaine* - **Lignocaine (Lidocaine)** is an **intermediate-acting amide local anesthetic**, with a duration of action around 1-3 hours. - It is one of the most commonly used local anesthetics, but its duration is not as long as that of dibucaine.

Q: From which part of the Papaver somniferum plant does the latex, commonly referred to as 'milk', exude?

Unripe capsule of the plant. ***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.

Q: Which of the following is an example of topical administration producing only local effects (not systemic)?

Topical corticosteroid cream. ***Topical corticosteroid cream*** - When applied to the skin for conditions like dermatitis, topical corticosteroids primarily exert their effects at the site of application, reducing **local inflammation** and itching. - While systemic absorption can occur with potent steroids over large areas, typical use aims for **localized action** without significant systemic effects. *Sublingual nitroglycerin* - This route is designed for **rapid systemic absorption** through the oral mucosa, bypassing first-pass metabolism to quickly treat angina. - The goal is a **widespread vasodilatory effect** throughout the body, not a local one within the mouth. *Transdermal patch* - Transdermal patches, such as those for nicotine or fentanyl, are specifically designed to deliver medication **systemically** through the skin into the bloodstream over a prolonged period. - They provide a **sustained release** and systemic therapeutic effect throughout the body. *Rectal diazepam* - Administered rectally, diazepam is absorbed into the systemic circulation to produce **CNS effects** such as sedation, anxiolysis, or anticonvulsant activity. - Although the administration is local, the intended clinical effect is **systemic** and widespread throughout the body.

Q: Which drug is not administered as a transdermal patch?

Morphine. ***Morphine*** - **Morphine** is generally not administered transdermally due to its **poor lipid solubility** [1] and **large molecular size**, which limit its ability to penetrate the skin effectively. - While experimental patches have been developed, they are **not widely available** or commonly used in clinical practice for systemic delivery. *Fentanyl* - **Fentanyl** is a potent opioid that is commonly administered via a **transdermal patch** for chronic pain management [2]. - Its **high lipid solubility** and small molecular size allow it to be effectively absorbed through the skin, providing sustained analgesia. *Clonidine* - **Clonidine** is an alpha-2 adrenergic agonist available as a **transdermal patch** for the treatment of **hypertension**. - The patch provides a **continuous and steady release** of the drug, leading to consistent blood pressure control. *Diclofenac* - **Diclofenac** is a non-steroidal anti-inflammatory drug (NSAID) available in **transdermal patch** formulations for topical pain relief. - These patches are used for localized pain conditions like **osteoarthritis** and provide targeted drug delivery with reduced systemic side effects.

Q: Which of the following is a PGE1 analogue used in medical treatments?

Alprostadil. ***Alprostadil*** - **Alprostadil** is a synthetic **prostaglandin E1 (PGE1)** analogue. - It is used in neonates to maintain the **patency of the patent ductus arteriosus** and in adults for the treatment of **erectile dysfunction**. *Carboprost* - **Carboprost** is a synthetic analogue of **prostaglandin F2 alpha (PGF2α)**. - It is primarily used to manage **postpartum hemorrhage** due to its potent uterotonic effects. *Epoprostenol* - **Epoprostenol** is a synthetic analogue of **prostacyclin (PGI2)**. - It is known for its potent **vasodilatory** and **antiplatelet** properties, making it useful in treating **pulmonary arterial hypertension**. *Dinoprostone* - **Dinoprostone** is a synthetic form of **prostaglandin E2 (PGE2)**. - It is used to **induce labor** or **cervical ripening** due to its role in uterine contractions and cervical dilation.

Q: Which drug is used in the treatment of Type I tyrosinemia?

Nitisinone. ***Nitisinone*** - **Nitisinone** (brand name Orfadin) is specifically approved for the treatment of **hereditary tyrosinemia type 1 (HT-1)**. - It works by inhibiting 4-hydroxyphenylpyruvate dioxygenase, an enzyme upstream of the deficient enzyme in HT-1, thereby reducing the production of toxic metabolites. *Alogliptin* - **Alogliptin** is a dipeptidyl peptidase-4 (DPP-4) inhibitor used in the management of **Type 2 diabetes mellitus**. - It helps to lower blood glucose levels by increasing the half-life of **incretin hormones**, which stimulate insulin release. *Pemoline* - **Pemoline** is a central nervous system (CNS) stimulant that was formerly used to treat **attention deficit hyperactivity disorder (ADHD)** and narcolepsy. - Its use has been largely discontinued due to concerns about its potential for **liver toxicity**. *Milrinone* - **Milrinone** is a phosphodiesterase-3 inhibitor used in the short-term management of **decompensated heart failure**. - It increases **cardiac contractility** and causes vasodilation, improving cardiac output.

Q: Ranibizumab is a monoclonal antibody against?

VEGF. ***VEGF*** - **Ranibizumab** is a **monoclonal antibody** specifically designed to inhibit **vascular endothelial growth factor A (VEGF-A)**. - By binding to VEGF-A, ranibizumab prevents its interaction with receptors on endothelial cells, thereby inhibiting **angiogenesis** and reducing vascular permeability, which is crucial in treating conditions like **wet age-related macular degeneration (AMD)** and **diabetic macular edema**. *Interleukin-6* - **Interleukin-6 (IL-6)** is a **pro-inflammatory cytokine** involved in various autoimmune and inflammatory diseases. - Monoclonal antibodies targeting IL-6, such as **tocilizumab**, are used in conditions like **rheumatoid arthritis** and **cytokine release syndrome**, not for ocular neovascularization. *Cluster of Differentiation 20* - **Cluster of Differentiation 20 (CD20)** is a protein found on the surface of **B lymphocytes**. - Monoclonal antibodies against CD20, like **rituximab**, are used in the treatment of **B-cell lymphomas**, **leukemia**, and certain **autoimmune diseases**, not for conditions requiring anti-VEGF therapy. *Epidermal Growth Factor Receptor* - The **epidermal growth factor receptor (EGFR)** is a **tyrosine kinase receptor** involved in cell growth and proliferation. - Monoclonal antibodies targeting EGFR, such as **cetuximab** and **panitumumab**, are used in the treatment of various **cancers**, particularly **colorectal cancer** and **head and neck cancer**.

Q: Pyridoxine is used in treatment of ?

Homocystinuria. ***Homocystinuria*** - **Pyridoxine (vitamin B6)** is a cofactor for the enzyme **cystathionine beta-synthase**, which is deficient in many forms of homocystinuria. - In pyridoxine-responsive homocystinuria, high doses of pyridoxine can help reduce **homocysteine levels** by stimulating residual enzyme activity. *Galactosemia* - This is an inherited disorder affecting the body's ability to metabolize **galactose**, due to deficiency of enzymes like galactose-1-phosphate uridyltransferase. - Treatment primarily involves dietary restriction of **galactose** and lactose, not pyridoxine. *Phenylketonuria* - This metabolic disorder results from a deficiency in **phenylalanine hydroxylase**, leading to a buildup of phenylalanine. - Treatment involves a strict **low-phenylalanine diet** and sometimes sapropterin (BH4). *Propionic acidemia* - This organic acidemia is caused by a deficiency in **propionyl-CoA carboxylase**, an enzyme requiring **biotin** as a cofactor. - Treatment involves dietary protein restriction and often carnitine supplementation, with **biotin** sometimes used, but not pyridoxine.

Question 1

What is the mechanism of action of Basiliximab?

Accepted Answer

IL-2 receptor antagonist

Answer

IL-1 receptor antagonist

Answer

Anti-CD3 antibody

Answer

TNF inhibitor

Question 2

Which of the following is a long-acting local anesthetic?

Accepted Answer

Dibucaine

Answer

Prilocaine

Answer

Procaine

Answer

Lignocaine

Question 3

A patient undergoing a minor surgical procedure is given lignocaine injection. Assertion: Local anaesthetics act by blocking nerve conduction. Reason: Small fibers and non-myelinated fibers are blocked more easily than large myelinated fibers.

Accepted Answer

Both Assertion and Reason are true, and Reason is not the correct explanation for Assertion

Answer

Assertion is false, but Reason is true

Answer

Both Assertion and Reason are true, and Reason is the correct explanation for Assertion

Answer

Assertion is true, but Reason is false

Question 4

From which part of the Papaver somniferum plant does the latex, commonly referred to as 'milk', exude?

Accepted Answer

Unripe capsule of the plant

Answer

Leaf of the plant

Answer

Root of the plant

Answer

Seeds of the plant

Question 5

Which of the following is an example of topical administration producing only local effects (not systemic)?

Accepted Answer

Topical corticosteroid cream

Answer

Sublingual nitroglycerin

Answer

Transdermal patch

Answer

Rectal diazepam

Question 6

Which drug is not administered as a transdermal patch?

Accepted Answer

Morphine

Answer

Fentanyl

Answer

Clonidine

Answer

Diclofenac

Question 7

Which of the following is a PGE1 analogue used in medical treatments?

Accepted Answer

Alprostadil

Answer

Carboprost

Answer

Epoprostenol

Answer

Dinoprostone

Question 8

Which drug is used in the treatment of Type I tyrosinemia?

Accepted Answer

Nitisinone

Answer

Pemoline

Answer

Alogliptin

Answer

Milrinone

Question 9

Ranibizumab is a monoclonal antibody against?

Accepted Answer

VEGF

Answer

Interleukin-6

Answer

Cluster of Differentiation 20

Answer

Epidermal Growth Factor Receptor

Question 10

Pyridoxine is used in treatment of ?

Accepted Answer

Homocystinuria

Answer

Galactosemia

Answer

Phenylketonuria

Answer

Propionic acidemia

General Pharmacology — MCQs

General Pharmacology — MCQs

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