FMGE 2026 - Pharmacology Practice Questions

Q: A patient started on a new cholesterol -lowering medication develops facial flushing and erythema, as shown in the image. Which of the following drugs is most likely responsible for this presentation?

Niacin. ***Niacin*** - Facial flushing and erythema are the most common **dose-limiting side effects** of niacin therapy, caused by prostaglandin-mediated **vasodilation**. - This reaction can be significantly reduced by premedication with **aspirin** or by starting at a low dose and titrating slowly. *Lovastatin* - Statins generally do not cause flushing; their primary adverse effects include **myopathy**, myalgia, and asymptomatic elevations in **transaminases**. - **Rhabdomyolysis** is a rare but serious potential complication, not associated with the skin findings described. *Ezetimibe* - Ezetimibe is generally well-tolerated and does not typically present with significant cutaneous side effects like flushing. - Its primary concerns involve gastrointestinal symptoms such as **diarrhea** and abdominal pain, or rare elevated **liver enzymes** when used with statins. *Gemfibrozil* - Fibrates like gemfibrozil may increase the risk of **gallstones** due to increased cholesterol excretion in bile. - They do not typically cause facial flushing; their primary side effect is an increased risk of **myopathy**, especially when combined with statins.

Q: Which of the following drugs is least commonly used as first -line therapy for uncomplicated urinary tract infections ?

Fluoroquinolones. ***Fluoroquinolones*** - Due to their potential for **serious side effects**, such as **tendonitis**, **tendon rupture**, and **peripheral neuropathy**, the FDA has restricted their use for uncomplicated urinary tract infections. - They are typically reserved for **complicated infections**, such as **pyelonephritis**, because they should be preserved for more severe conditions to prevent the development of **antibiotic resistance**. *Nitrofurantoin* - This is a standard **first-line agent** for the treatment of uncomplicated **cystitis** due to its high concentration in the urine. - It has a low rate of resistance and is generally well-tolerated, making it an excellent choice for outpatient therapy. *Sulfonamides* - Trimethoprim-sulfamethoxazole (TMP-SMX) is widely recommended as a **first-line treatment** for uncomplicated UTIs in areas where resistance rates are known to be low. - It is effective against most common uropathogens, particularly **Escherichia coli**. *Fosfomycin* - Often administered as a single-dose therapy, **fosfomycin** is an approved **first-line agent** for uncomplicated lower urinary tract infections. - It is highly effective due to its ability to maintain high concentrations in the bladder and its unique mechanism of action which helps overcome **multidrug resistance**.

Q: A patient undergoing chemotherapy develops hemorrhagic cystitis. Which of the following drugs is most commonly responsible?

Ifosfamide. ***Ifosfamide*** - Ifosfamide is an alkylating agent known to cause **hemorrhagic cystitis** due to the accumulation of its toxic metabolite, **acrolein**, in the bladder. - To prevent this complication, **mesna** (2-mercaptoethane sulfonate) is routinely administered alongside ifosfamide to neutralize acrolein. *Bleomycin* - The primary and most serious dose-limiting side effect of bleomycin is **pulmonary fibrosis**. - It is not associated with bladder toxicity or hemorrhagic cystitis, as it mainly affects the lungs and skin. *Vincristine* - Vincristine is a vinca alkaloid that commonly causes **peripheral neuropathy**, manifesting as loss of deep tendon reflexes. - It is generally **myelosparing**, meaning it does not typically cause the bone marrow suppression seen with other chemotherapeutic agents, nor does it cause cystitis. *Methotrexate* - Methotrexate is an antimetabolite primarily associated with **mucositis** and **stomatitis** due to its effect on rapidly dividing cells. - It can cause hepatotoxicity and myelosuppression, but it is not a classic cause of bladder inflammation like ifosfamide.

Q: A 40-year-old patient with refractory epilepsy is on a multi-drug antiepileptic regimen. Two weeks after a dosage adjustment, he develops diffuse morbilliform rash, fever and oral mucosal erosions. Which of the following antiepileptic drugs can most saf ely be continued?

Clobazam. ***Clobazam*** - Clobazam is a **benzodiazepine** that acts as a positive allosteric modulator of GABA-A receptors, which is structurally distinct from traditional aromatic antiepileptic drugs (AEDs) like phenytoin or lamotrigine. - It is not associated with the **hypersensitivity reactions** (like DRESS syndrome or SJS/TEN) commonly triggered by the aromatic AEDs involved in the patient's current regimen. *Phenytoin* - Phenytoin is a known culprit for drug-induced **hypersensitivity reactions** (DRESS syndrome) due to its metabolites (arene oxides) that cause immune dysregulation. - It is strictly contraindicated in patients presenting with **morbilliform rashes** and systemic symptoms like fever and mucosal involvement, as continuation can lead to fatal complications. *Valproate* - Valproate is an aliphatic AED, but it can contribute to **DRESS syndrome** and also causes **hepatotoxicity**, which exacerbates the patient's systemic inflammatory response. - It is generally advised to discontinue implicated agents in a multidrug regimen to stabilize the patient, making it an unsafe drug to continue in this clinical context. *Lamotrigine* - Lamotrigine has a high potential for causing **severe cutaneous adverse reactions (SCARs)** such as **Stevens-Johnson Syndrome (SJS)** and **Toxic Epidermal Necrolysis (TEN)**, especially when titrated rapidly. - Given the presence of **oral mucosal erosions**, this drug is a highly suspicious trigger and must be discontinued immediately to prevent further progression.

Q: Which immunosuppressive medication blocks the effects of interleukin -2 (IL-2) without inhibiting calcineurin activity?

Sirolimus. ***Sirolimus*** - Sirolimus binds to the **FK-binding protein 12 (FKBP-12)**, forming a complex that specifically inhibits **mTOR (mammalian target of rapamycin)** kinase. - By inhibiting mTOR, it disrupts cell cycle progression from the G1 to the S phase, effectively blocking the **IL-2-mediated signal transduction** pathway without affecting calcineurin. *Tacrolimus* - Tacrolimus acts by binding to **FKBP-12**, but the resulting complex specifically inhibits **calcineurin**. - This inhibition prevents the dephosphorylation and activation of **NFAT (nuclear factor of activated T-cells)**, thereby suppressing IL-2 transcription. *Mycophenolate mofetil* - This drug acts by inhibiting **inosine monophosphate dehydrogenase (IMPDH)**, which is the rate-limiting enzyme in the **de novo synthesis of guanosine nucleotides**. - It primarily targets lymphocyte proliferation by depleting the guanosine pool, rather than interacting with IL-2 pathways or calcineurin. *Azathioprine* - Azathioprine is a prodrug of **6-mercaptopurine**, an antimetabolite that gets converted into thioinosinic acid. - It inhibits **purine synthesis** and DNA replication, causing toxicity to rapidly dividing cells like lymphocytes, but it does not specifically block the IL-2 receptor signaling pathway.

Q: Furosemide -induced hearing loss occurs primarily by damaging which structure?

Na⁺-K⁺-2Cl⁻cotransporter in stria vascularis. ### ***Na⁺-K⁺-2Cl⁻ cotransporter in stria vascularis*** - Furosemide is a **loop diuretic** that inhibits the **Na⁺-K⁺-2Cl⁻ cotransporter (NKCC2)** in the thick ascending limb of the loop of Henle, but it also inhibits the **NKCC1** isoform found in the **stria vascularis** of the inner ear. - This inhibition disrupts the **endocochlear potential** by reducing potassium secretion into the endolymph, leading to temporary or permanent **sensorineural hearing loss**. *Outer hair cells in Organ of Corti* - While aminoglycosides are known to be directly **ototoxic** to the **outer hair cells** of the Organ of Corti, this is not the primary site of damage for loop diuretics. - Loop diuretics specifically alter the ionic gradient between the **endolymph** and the **perilymph** rather than causing direct cellular toxicity to hair cells. *Vestibulocochlear nerve* - The **vestibulocochlear nerve (CN VIII)** is typically damaged by acoustic neuromas or toxins like heavy metals, but it is not the target of furosemide-induced injury. - Symptoms of loop diuretic toxicity involve hearing loss rather than the primary neuropathic deficits associated with direct nerve toxicity. *Cochlear duct basement membrane* - Damage to the **basilar membrane** (often via noise-induced trauma or mechanical injury) results in hearing loss, but this is a structural failure unrelated to furosemide. - Furosemide mechanism is **biochemical/metabolic** regarding electrolyte transport, not an injury to the physical architecture of the membrane.

Question 1

A patient started on a new cholesterol -lowering medication develops facial flushing and erythema, as shown in the image. Which of the following drugs is most likely responsible for this presentation?

Accepted Answer

Niacin

Answer

Lovastatin

Answer

Ezetimibe

Answer

Gemfibrozil

Question 2

Which of the following drugs is least commonly used as first -line therapy for uncomplicated urinary tract infections ?

Accepted Answer

Fluoroquinolones

Answer

Nitrofurantoin

Answer

Sulfonamides

Answer

Fosfomycin

Question 3

A patient undergoing chemotherapy develops hemorrhagic cystitis. Which of the following drugs is most commonly responsible?

Accepted Answer

Ifosfamide

Answer

Bleomycin

Answer

Vincristine

Answer

Methotrexate

Question 4

A 40-year-old patient with refractory epilepsy is on a multi-drug antiepileptic regimen. Two weeks after a dosage adjustment, he develops diffuse morbilliform rash, fever and oral mucosal erosions. Which of the following antiepileptic drugs can most saf ely be continued?

Accepted Answer

Clobazam

Answer

Phenytoin

Answer

Valproate

Answer

Lamotrigine

Question 5

Which immunosuppressive medication blocks the effects of interleukin -2 (IL-2) without inhibiting calcineurin activity?

Accepted Answer

Sirolimus

Answer

Tacrolimus

Answer

Mycophenolate mofetil

Answer

Azathioprine

Question 6

Furosemide -induced hearing loss occurs primarily by damaging which structure?

Accepted Answer

Na⁺-K⁺-2Cl⁻cotransporter in stria vascularis

Answer

Outer hair cells in Organ of Corti

Answer

Vestibulocochlear nerve

Answer

Cochlear duct basement membrane

FMGE 2026 — Pharmacology