Central Nervous System Pharmacology Practice Questions

Q: Exanthema is caused by which drug ?

Phenytoin. ***Phenytoin*** - **Phenytoin** is well-known to cause an exanthematous drug reaction, often presenting as a widespread, symmetrical rash that can be **maculopapular** - This adverse effect is part of a spectrum of dermatological reactions to phenytoin, which can range from mild rashes to severe cutaneous adverse reactions (SCARs) like **Stevens-Johnson syndrome (SJS)** or **toxic epidermal necrolysis (TEN)** - Phenytoin is one of the **most common drugs causing drug-induced exanthema** *Valproate* - While valproate can cause various side effects, **skin rashes and exanthema are uncommon** and not typically considered a characteristic adverse drug reaction - More common side effects of valproate include gastrointestinal disturbances, **tremor**, **weight gain**, and **hepatotoxicity** *NTG (Nitroglycerin)* - Nitroglycerin is primarily used for cardiovascular conditions and its common side effects are related to **vasodilation**, such as **headache**, dizziness, and flushing - **Exanthematous rashes are not a typical adverse effect** associated with nitroglycerin use *Digoxin* - Digoxin can cause various side effects, particularly **cardiac arrhythmias** and **gastrointestinal symptoms** - Although rare allergic reactions including skin rashes can occur, **exanthema is not a prominent or common adverse effect** of digoxin

Q: Ketamine belongs to which of the following group of drugs ?

Phencyclidine. ***Phencyclidine***- **Ketamine** is structurally related to **phencyclidine (PCP)**, sharing a similar mechanism of action as an **NMDA receptor antagonist** [2]. Ketamine is also categorized as a general anesthetic [1].- Both drugs primarily induce a state of **dissociative anesthesia**, characterized by a trance-like state without loss of consciousness [2].*Phenols*- **Phenols** are a class of organic compounds typically used as antiseptics and disinfectants, such as carbolic acid.- They do not possess anesthetic properties or a similar chemical structure to ketamine.*Barbiturate*- **Barbiturates** are central nervous system depressants that produce a wide range of effects, including sedation, hypnosis, and anesthesia [3].- They act primarily by enhancing the activity of **GABA-A receptors**, a different mechanism than ketamine.*Benzodiazepine*- **Benzodiazepines** are a class of psychoactive drugs primarily used for treating anxiety, insomnia, and seizures.- They also act by enhancing **GABA-A receptor** activity, leading to central nervous system depression, unlike ketamine's dissociative effects.

Q: A recently approved drug for treatment of the 'off phenomenon' in Parkinsonism:

Safinamide. ***Safinamide*** - **Safinamide** is a recently approved drug that acts as a **reversible monoamine oxidase B (MAO-B) inhibitor** and also modulates **glutamate release**. - It is specifically indicated as an adjunct therapy for Parkinson's disease patients experiencing motor fluctuations ("off" time) treated with levodopa. *Ziconotide* - **Ziconotide** is a synthetic **conopeptide** that selectively blocks N-type calcium channels. - It is used for the management of severe chronic pain in patients for whom intrathecal therapy is warranted, not for Parkinsonism. *Evenamide* - **Evenamide** is an investigational drug, currently in clinical trials, primarily developed as an adjunctive treatment for **schizophrenia**. - It works as a **glutamate modulator** but is not approved for Parkinson's disease. *Lacosamide* - **Lacosamide** is an anti-epileptic drug that selectively enhances **slow inactivation of voltage-gated sodium channels**. - It is used for the treatment of **partial-onset seizures** and has no indication for Parkinson's disease.

Q: Modafinil is approved by FDA for treatment of all except:

Lethargy in depression. ***Lethargy in depression*** - Modafinil is **not FDA-approved** for treating lethargy or fatigue specifically in the context of depression. Its primary indications are for disorders of excessive daytime sleepiness. - While it may be used off-label in some cases for depression-related fatigue, it lacks formal FDA approval and specific efficacy data for this indication. *Narcolepsy* - Modafinil is **FDA-approved** as a wakefulness-promoting agent for the treatment of excessive daytime sleepiness associated with **narcolepsy**. - It helps reduce the frequency and severity of sleep attacks by promoting wakefulness through effects on **dopamine**, **norepinephrine**, and **histamine** systems in the brain. *Shift work sleep disorder (SWSD)* - Modafinil is **FDA-approved** to improve wakefulness in patients with excessive sleepiness associated with **shift work sleep disorder**. - It helps individuals working non-traditional hours (night shifts, rotating shifts) maintain alertness during their work periods. *Obstructive sleep apnea syndrome (OSAS)* - Modafinil is **FDA-approved** as an **adjunctive treatment** for residual excessive daytime sleepiness in patients with **obstructive sleep apnea/hypopnea syndrome (OSAHS)** who are receiving adequate treatment with CPAP. - It addresses persistent sleepiness that remains even after appropriate primary airway management.

Q: Which drug is suitable for epilepsy related to a brain tumor?

Levetiracetam. ***Levetiracetam*** - Levetiracetam is often preferred for **tumor-related epilepsy** due to its favorable **pharmacokinetic profile**, minimal **drug-drug interactions**, and broad spectrum of activity against various seizure types. - It does not significantly induce or inhibit hepatic enzymes, making it a safer option for patients who may be on other medications for their tumor or cancer treatment. *Phenytoin* - **Phenytoin** has a narrow **therapeutic window** and significant **drug-drug interactions** due to its potent hepatic enzyme induction, which can complicate concomitant use with **chemotherapy** or other medications. - It also has a dose-dependent non-linear pharmacokinetic profile, making dose adjustments challenging and increasing the risk of **toxicity**. *Phenobarbitone* - **Phenobarbitone** is a potent enzyme inducer and has a high potential for **sedation** and cognitive side effects, which can significantly impair the quality of life for patients. - Its long half-life and propensity for **drug interactions** make it less desirable, especially in patients with brain tumors who may experience other neurological deficits. *Carbamazepine* - **Carbamazepine** is another potent **enzyme inducer** that can lead to significant **drug interactions**, particularly with chemotherapy agents, altering their metabolism and efficacy. - It often causes side effects like **drowsiness**, **dizziness**, and can lead to **hyponatremia**, which may be problematic in patients who are already compromised.

Q: A patient with grand mal epilepsy would likely be under treatment with:

Phenytoin. ***Phenytoin*** - **Phenytoin** is a classic and effective anticonvulsant widely used for treating **generalized tonic-clonic seizures** (grand mal epilepsy) [2], [4]. - Its mechanism involves blocking voltage-gated sodium channels, stabilizing the neuronal membrane and preventing the repetitive firing of action potentials [3]. *Pentobarbital* - **Pentobarbital** is a barbiturate primarily used as a sedative or for inducing medical coma, especially in refractory status epilepticus. - While it has anticonvulsant properties, it is not a first-line agent for the long-term management of chronic grand mal epilepsy due to its side effect profile and sedative effects. *Trimethadione* - **Trimethadione** is an older anticonvulsant specifically used for **absence seizures** (petit mal epilepsy). - It works by reducing T-type calcium currents in thalamic neurons, a mechanism distinct from that required for generalized tonic-clonic seizures [1]. *Meprobamate* - **Meprobamate** is a carbamate derivative primarily used as an anxiolytic and muscle relaxant. - It has sedative properties but is not considered an effective or appropriate treatment for any type of epilepsy, including grand mal seizures.

Q: A 65-year-old gentleman is having tremors, rigidity and reduced mobility. He is likely to be benefited by?

Bromocriptine. ***Bromocriptine*** - The patient's symptoms (tremors, rigidity, reduced mobility) are classic for **Parkinson's disease**, which involves a deficiency of **dopamine** [1]. - **Bromocriptine** is a **dopamine agonist** that directly stimulates dopamine receptors, thereby alleviating Parkinsonian symptoms [2]. *Reserpine* - **Reserpine** depletes **monoamines**, including dopamine, by inhibiting their uptake into synaptic vesicles. - This action would worsen Parkinsonian symptoms rather than improve them. *Acyclovir* - **Acyclovir** is an **antiviral agent** used to treat herpes virus infections. - It has no role in the management of movement disorders like Parkinson's disease. *Alpha methyl dopa* - **Alpha-methyldopa** is an **antihypertensive agent** that reduces sympathetic outflow by acting as an alpha-2 adrenergic agonist. - It does not address the dopamine deficiency seen in Parkinson's disease and is not used to treat movement disorders.

Q: The following drugs are used for prophylaxis of migraine except

Meperidine. ***Meperidine*** - **Meperidine** (pethidine) is an **opioid analgesic** primarily used for acute pain relief, not for migraine prophylaxis. - Its use can lead to **opioid dependence** and even worsen headache frequency in the long term, known as medication overuse headache. *Metoprolol* - **Metoprolol** is a **beta-blocker** commonly prescribed for migraine prophylaxis, especially in patients with co-existing hypertension or anxiety. - It works by modulating **adrenergic activity** and is considered a first-line agent for preventing migraine attacks. *Valproate* - **Valproate** (valproic acid/divalproex sodium) is an **anticonvulsant** that is effective in migraine prophylaxis. - It is thought to work by increasing **GABA activity** and modulating neuronal excitability, reducing migraine frequency. *Topiramate* - **Topiramate** is an **anticonvulsant** frequently used for migraine prophylaxis, particularly favored for its potential side effect of **weight loss**. - Its mechanism involves multiple actions, including **GABA potentiation**, glutamate antagonism, and modulation of voltage-gated ion channels.

Q: Drugs used for Prophylaxis of migraine include the following except?

Sumatriptan. ***Sumatriptan*** - **Sumatriptan** is a **triptan** drug class medication (5-HT1B/1D receptor agonist) used for the **acute treatment** of migraine attacks, not for prophylaxis. - It works by causing cranial vasoconstriction and inhibiting neuropeptide release, thereby aborting an active migraine attack. - Triptans are contraindicated in patients with coronary artery disease due to their vasoconstrictive effects. *Valproate* - **Valproate** (sodium valproate/divalproex) is an established **first-line agent for migraine prophylaxis**. - It exerts antimigraine effects through modulation of GABAergic transmission, voltage-gated sodium channels, and possibly NMDA receptor inhibition. - Effective dose for prophylaxis is typically 500-1000 mg/day in divided doses. *Propranolol* - **Propranolol**, a non-selective **beta-blocker**, is one of the most commonly used **first-line prophylactic agents** for migraine. - It reduces migraine frequency through multiple mechanisms including inhibition of norepinephrine, reduction of cortical spreading depression, and stabilization of vascular tone. - Typical prophylactic dose is 80-240 mg/day in divided doses. *TCAs* - **Tricyclic antidepressants (TCAs)**, particularly **amitriptyline**, are highly effective **first-line prophylactic agents** for migraine. - They work through modulation of serotonin and norepinephrine reuptake, as well as effects on ion channels and pain pathways. - Amitriptyline is typically used at doses of 25-150 mg at bedtime for migraine prophylaxis.

Question 1

Exanthema is caused by which drug ?

Accepted Answer

Phenytoin

Answer

Valproate

Answer

NTG

Answer

Digoxin

Question 2

Ketamine belongs to which of the following group of drugs ?

Accepted Answer

Phencyclidine

Answer

Phenols

Answer

Barbiturate

Answer

Benzodiazepine

Question 3

A recently approved drug for treatment of the 'off phenomenon' in Parkinsonism:

Accepted Answer

Safinamide

Answer

Ziconotide

Answer

Evenamide

Answer

Lacosamide

Question 4

Modafinil is approved by FDA for treatment of all except:

Accepted Answer

Lethargy in depression

Answer

Narcolepsy

Answer

Shift work sleep disorder (SWSD)

Answer

Obstructive sleep apnea syndrome (OSAS)

Question 5

Which drug is suitable for epilepsy related to a brain tumor?

Accepted Answer

Levetiracetam

Answer

Phenytoin

Answer

Phenobarbitone

Answer

Carbamazepine

Question 6

What is the drug of choice for treatment of simple partial seizures?

Accepted Answer

Carbamazepine

Answer

Phenytoin

Answer

Valproate

Answer

Barbiturate

Question 7

A patient with grand mal epilepsy would likely be under treatment with:

Accepted Answer

Phenytoin

Answer

Pentobarbital

Answer

Trimethadione

Answer

Meprobamate

Question 8

A 65-year-old gentleman is having tremors, rigidity and reduced mobility. He is likely to be benefited by?

Accepted Answer

Bromocriptine

Answer

Reserpine

Answer

Acyclovir

Answer

Alpha methyl dopa

Question 9

The following drugs are used for prophylaxis of migraine except

Accepted Answer

Meperidine

Answer

Metoprolol

Answer

Valproate

Answer

Topiramate

Question 10

Drugs used for Prophylaxis of migraine include the following except?

Accepted Answer

Sumatriptan

Answer

Valproate

Answer

TCAs

Answer

Propranolol

Central Nervous System Pharmacology — MCQs

Central Nervous System Pharmacology — MCQs

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