Adverse Effects and Management — MCQs
An SSRI antidepressant, such as fluoxetine, will be prescribed for an adult patient. You should advise him or her that two of the most likely side effects or adverse responses that may eventually occur at therapeutic blood levels are which of the following?
What is the most common side effect of haloperidol?
A patient on clozapine develops fever, confusion, and muscle rigidity. CK is elevated. Most appropriate next step?
Which drug is not considered a mood stabilizer?
What is the treatment for extrapyramidal side effects induced by Haloperidol?
Which of the following medications is most commonly associated with causing Neuroleptic Malignant Syndrome (NMS)?
A patient on SSRI sertraline was also prescribed amitriptyline and subsequently developed serotonin toxicity. What is the likely treatment for serotonin toxicity?
Sedation as an adverse effect is most commonly associated with which of the following atypical antipsychotics?
All of the following are adverse effects of thalidomide except:
Which one of the following drugs has a narrow therapeutic range?
Adverse Effects and Management Indian Medical PG Practice Questions and MCQs
Question 1: An SSRI antidepressant, such as fluoxetine, will be prescribed for an adult patient. You should advise him or her that two of the most likely side effects or adverse responses that may eventually occur at therapeutic blood levels are which of the following?
- A. Sexual dysfunction and sleep disturbances (Correct Answer)
- B. Sexual dysfunction and nausea
- C. Headache and diarrhea
- D. Tremor and weight gain
Explanation: ***Sexual dysfunction and sleep disturbances*** - **Sexual dysfunction** is one of the most common and persistent adverse effects of SSRIs, affecting 40-65% of patients and continuing throughout treatment at therapeutic levels [2], [3]. - **Sleep disturbances** (insomnia or altered sleep architecture) can persist during long-term SSRI therapy and are among the eventual side effects patients experience [1], [2], [3]. - Both effects are characteristic of chronic SSRI use and significantly impact patient compliance and quality of life. *Sexual dysfunction and nausea* - While **sexual dysfunction** is indeed very common and persistent, **nausea** is typically a transient side effect that occurs during the first 1-2 weeks of treatment and usually resolves with continued use [2]. - The question specifically asks about *eventual* occurrence at therapeutic levels over time, making nausea less appropriate as it is not a chronic issue. *Tremor and weight gain* - **Tremor** is not among the most common side effects of SSRIs and occurs less frequently than sexual dysfunction or sleep disturbances. - **Weight gain** can occur with some SSRIs (particularly paroxetine), but fluoxetine is actually considered weight-neutral or may even cause weight loss in some patients, making this combination less likely for fluoxetine specifically [1]. *Headache and diarrhea* - Both **headache** and **diarrhea** are common initial side effects when starting SSRIs but typically improve or resolve within the first few weeks of treatment [1]. - These are transient effects rather than eventual persistent side effects that characterize long-term therapeutic use.
Question 2: What is the most common side effect of haloperidol?
- A. Hypotension
- B. Dryness of mouth
- C. Tic disorder
- D. Akathisia (Correct Answer)
Explanation: ***Akathisia*** - **Akathisia** is one of the **most common extrapyramidal symptoms (EPS)** associated with haloperidol, occurring in **20-75% of patients**. - It is characterized by a feeling of **inner restlessness** and an **inability to stay still**, often manifesting as pacing, rocking, or shifting weight. - Haloperidol, a high-potency **first-generation antipsychotic**, has a high propensity to cause EPS, including akathisia, due to its **strong dopamine D2 receptor blockade** in the nigrostriatal pathway. - Along with drug-induced parkinsonism, akathisia is among the most frequently encountered side effects with haloperidol use. *Hypotension* - While orthostatic hypotension can occur with antipsychotics, particularly those with strong **alpha-1 adrenergic blockade** (e.g., lower potency first-generation antipsychotics like chlorpromazine, or some second-generation antipsychotics), it is not the most common side effect of haloperidol. - Haloperidol has relatively **weak alpha-1 blocking activity** compared to other antipsychotics. *Dryness of mouth* - **Dryness of mouth (xerostomia)** is a common anticholinergic side effect of some antipsychotics, but it is not the most common or prominent side effect of haloperidol. - Haloperidol has relatively **weak anticholinergic activity** compared to lower potency antipsychotics. *Tic disorder* - **Tic disorders** are characterized by sudden, rapid, recurrent, nonrhythmic motor movements or vocalizations. - While haloperidol can be used to **treat severe tics** (e.g., in Tourette syndrome), it is not a common side effect of the medication itself; rather, it is a condition that antipsychotics like haloperidol may target therapeutically.
Question 3: A patient on clozapine develops fever, confusion, and muscle rigidity. CK is elevated. Most appropriate next step?
- A. Add antipyretic
- B. Continue clozapine
- C. Reduce dose
- D. Stop clozapine (Correct Answer)
Explanation: ***Stop clozapine*** - The presentation of **fever, confusion, muscle rigidity**, and elevated **creatine kinase (CK)** in a patient on clozapine is highly suggestive of **Neuroleptic Malignant Syndrome (NMS)**, a potentially fatal adverse reaction. - **Immediate discontinuation** of the causative antipsychotic, in this case **clozapine**, is the cornerstone of NMS management to prevent further clinical deterioration and complications. *Add antipyretic* - While a **fever** is present, simply adding an **antipyretic** would only address a symptom and not the underlying severe adverse drug reaction, potentially delaying critical intervention. - The fever in NMS is often due to **hypothalamic dysfunction** and **muscle rigidity**, not just a simple infection responsive to antipyretics alone. *Continue clozapine* - Continuing clozapine in the presence of NMS symptoms would **exacerbate the condition**, leading to increased morbidity and mortality, as it is the likely causative agent. - Further exposure to the drug would worsen the **hyperthermia, muscle rigidity**, and potential **organ damage**. *Reduce dose* - **Reducing the dose** of clozapine is insufficient if NMS is suspected, as even lower doses can maintain the toxic effect and progression of the syndrome. - The priority is to remove the offending agent completely, rather than merely decreasing its concentration.
Question 4: Which drug is not considered a mood stabilizer?
- A. Lithium
- B. Lamotrigine
- C. Imipramine (Correct Answer)
- D. Carbamazepine
Explanation: ***Imipramine*** - Imipramine is a **tricyclic antidepressant (TCA)**, primarily used to treat depression, not to stabilize mood in bipolar disorder. - TCAs can sometimes induce **mania** or hypomania in individuals with bipolar disorder, thus they are generally not used as monotherapy for mood stabilization. *Lithium* - **Lithium** is considered the gold standard and one of the oldest and most effective **mood stabilizers** for bipolar disorder. - It works by modulating **neurotransmitter systems** and second messenger pathways in the brain. *Lamotrigine* - **Lamotrigine** is an **anticonvulsant** medication that is also recognized as an effective **mood stabilizer**, particularly for preventing depressive episodes in bipolar disorder. - Its mechanism involves stabilizing neuronal membranes by blocking **voltage-gated sodium channels**. *Carbamazepine* - **Carbamazepine** is an **anticonvulsant** medication often used as a **mood stabilizer** for the treatment of acute manic and mixed episodes in bipolar disorder. - It works by reducing the excitability of nerve impulses through blocking **voltage-sensitive sodium channels**.
Question 5: What is the treatment for extrapyramidal side effects induced by Haloperidol?
- A. Barbiturates
- B. SSRIs
- C. Benzodiazepines
- D. Anticholinergic drugs (Correct Answer)
Explanation: ***Anticholinergic drugs (effective treatment)*** - **Anticholinergic medications**, such as **benztropine** or **diphenhydramine**, are the primary treatment for **acute extrapyramidal symptoms (EPS)** like dystonia and parkinsonism induced by antipsychotics like haloperidol. - They work by **blocking muscarinic acetylcholine receptors**, helping to restore the balance between dopamine and acetylcholine in the basal ganglia. *Benzodiazepines (used for anxiety and muscle relaxation)* - While benzodiazepines can offer some relief for **akathisia** (a form of EPS characterized by restlessness) due to their sedative and muscle relaxant properties, they are **not the first-line treatment for other acute EPS** such as dystonia or parkinsonism. - They primarily enhance **GABAergic transmission** and are effective for anxiety and seizure control rather than direct antagonism of EPS mechanisms. *Barbiturates (used as sedative-hypnotic drugs)* - **Barbiturates** are strong central nervous system depressants used for sedation, anesthesia, and seizure control, but are **not indicated for the treatment of EPS**. - Their significant **sedative and addictive potential**, along with a narrow therapeutic index, makes them unsuitable for this purpose. *SSRIs (used for depression and anxiety)* - **SSRIs (Selective Serotonin Reuptake Inhibitors)** are antidepressants that work by increasing serotonin levels in the brain and are used to treat depression, anxiety, and obsessive-compulsive disorder. - They **do not have a direct role** in ameliorating dopamine-acetylcholine imbalance responsible for haloperidol-induced EPS.
Question 6: Which of the following medications is most commonly associated with causing Neuroleptic Malignant Syndrome (NMS)?
- A. Metoclopramide
- B. Phenothiazines
- C. Haloperidol (Correct Answer)
- D. Clozapine
Explanation: ***Haloperidol*** - **Haloperidol** is a potent **first-generation (typical) antipsychotic** (butyrophenone class) that strongly blocks **dopamine D2 receptors**. - This potent D2 antagonism is the primary mechanism underlying the development of **Neuroleptic Malignant Syndrome (NMS)**. - The risk of NMS is **highest** with high-potency typical antipsychotics like haloperidol, especially when initiated at **high doses** or with **rapid dose escalation**. - Haloperidol is the **most commonly cited** individual agent associated with NMS in medical literature. *Phenothiazines* - **Phenothiazines** (e.g., chlorpromazine, fluphenazine) are a class of **first-generation antipsychotics** that also cause NMS due to **dopamine D2 receptor blockade**. - While phenothiazines as a class are associated with NMS, **haloperidol** (a butyrophenone) is considered the **prototypical** and most commonly cited individual drug for NMS. - High-potency phenothiazines (like fluphenazine) carry higher NMS risk than low-potency ones (like chlorpromazine). *Metoclopramide* - Metoclopramide is primarily an **antiemetic** and **prokinetic agent** that has **dopamine-blocking** properties (D2 antagonist). - It has been **rarely** associated with NMS or NMS-like reactions, but this is far less common compared to potent antipsychotics. - Its primary use is for gastrointestinal disorders, not psychiatric conditions. *Clozapine* - **Clozapine** is an **atypical (second-generation) antipsychotic** with relatively **weak D2 receptor affinity** and stronger effects on serotonin receptors. - It has the **lowest risk** of causing NMS among all antipsychotics due to its unique receptor binding profile. - Clozapine is actually sometimes used as an alternative in patients who have experienced NMS with typical antipsychotics.
Question 7: A patient on SSRI sertraline was also prescribed amitriptyline and subsequently developed serotonin toxicity. What is the likely treatment for serotonin toxicity?
- A. Flumazenil
- B. Cyproheptadine (Correct Answer)
- C. L-Carnitine
- D. Leucovorin
- E. Naloxone
Explanation: ***Cyproheptadine*** - **Cyproheptadine** is a serotonin antagonist that can help reverse the effects of excessive serotonin in the central nervous system. - It works by blocking **serotonin 5-HT2A receptors**, which are implicated in the pathophysiology of serotonin toxicity. *Flumazenil* - **Flumazenil** is a benzodiazepine receptor antagonist used to reverse the effects of benzodiazepine overdose. - It has no role in the treatment of **serotonin toxicity**, as it does not affect serotonin pathways. *L-Carnitine* - **L-Carnitine** is a mitochondrial co-factor used in fatty acid metabolism, sometimes supplemented for certain metabolic disorders or muscle pain. - It does not have any direct action on **serotonin receptors** or the serotonin system, making it ineffective for serotonin toxicity. *Leucovorin* - **Leucovorin** (folinic acid) is used to counteract the effects of methotrexate toxicity or to enhance the effects of fluorouracil in chemotherapy. - It is not involved in modulating **neurotransmitter levels** or reversing the symptoms of serotonin toxicity. *Naloxone* - **Naloxone** is an opioid receptor antagonist used to reverse opioid overdose. - It has no effect on **serotonin receptors** or serotonergic pathways, making it ineffective for treating serotonin toxicity.
Question 8: Sedation as an adverse effect is most commonly associated with which of the following atypical antipsychotics?
- A. Risperidone
- B. Olanzapine
- C. Quetiapine (Correct Answer)
- D. Aripiprazole
Explanation: ***Quetiapine*** - **Quetiapine** is known for its strong **H1 histamine receptor blockade**, which directly contributes to its prominent sedating effects. - This sedation is often dose-dependent and can be beneficial for patients with insomnia or agitation, but it is also a common complaint and reason for discontinuation. - Among the options listed, quetiapine is classically taught as the **most sedating** atypical antipsychotic. *Risperidone* - While risperidone can cause some sedation [1], it is generally less sedating than quetiapine or olanzapine and is more commonly associated with **extrapyramidal symptoms (EPS)**, especially at higher doses [1]. - Its mechanism of action primarily involves **D2 dopamine receptor blockade** and **5-HT2A serotonin receptor blockade** [1]. *Olanzapine* - **Olanzapine** also causes significant sedation [1] due to its strong antagonism of **H1 histamine receptors** and **alpha-1 adrenergic receptors**. - Clinically, olanzapine's sedative effects are comparable to quetiapine, though quetiapine is traditionally emphasized in exam contexts as the most sedating among these options. - Olanzapine is additionally notable for significant **metabolic side effects** like weight gain and dyslipidemia. *Aripiprazole* - **Aripiprazole** acts as a **partial agonist** at D2 dopamine receptors and 5-HT1A serotonin receptors, and an antagonist at 5-HT2A serotonin receptors, which results in minimal sedation. - It is often considered to be more **activating** or have a **neutral** effect on sedation compared to other atypical antipsychotics.
Question 9: All of the following are adverse effects of thalidomide except:
- A. Constipation
- B. Myocarditis (Correct Answer)
- C. Peripheral neuropathy
- D. Sedation
Explanation: ***Myocarditis*** - **Myocarditis** is not an established adverse effect of thalidomide in standard pharmacology references. - While thalidomide can cause cardiovascular effects such as **bradycardia** and **thromboembolic events**, direct myocardial inflammation is not a recognized complication. - This is the correct answer as it is NOT an adverse effect of thalidomide. *Constipation* - **Constipation** is a very common gastrointestinal side effect of thalidomide due to its **anticholinergic-like effects**. - Patients often require proactive management with laxatives to mitigate this side effect. *Peripheral neuropathy* - **Peripheral neuropathy** is the most significant and dose-limiting adverse effect of thalidomide, often presenting as **sensory deficits** in a stocking-glove distribution. - It can be **irreversible** and may necessitate discontinuation of the drug. - This is a major concern requiring regular monitoring during treatment. *Sedation* - **Sedation** and **drowsiness** are common adverse effects of thalidomide due to its **central nervous system depressant properties**. - This effect often leads to administration before bedtime to minimize impact on daily activities.
Question 10: Which one of the following drugs has a narrow therapeutic range?
- A. Propranolol
- B. Phenytoin (Correct Answer)
- C. Piroxicam
- D. Prazosin
Explanation: ***Phenytoin*** - **Phenytoin** has a **narrow therapeutic index**, meaning there is a small difference between the therapeutic and toxic doses. - This necessitates **therapeutic drug monitoring** to ensure effective treatment while avoiding adverse effects like nystagmus, ataxia, or gingival hyperplasia. *Propranolol* - **Propranolol** is a **beta-blocker** used for hypertension, angina, and arrhythmias, generally considered to have a wide therapeutic range. - While dose adjustments are common, routine therapeutic drug monitoring is typically **not required** due to its relatively safe profile at higher doses compared to drugs like phenytoin. *Piroxicam* - **Piroxicam** is a **nonsteroidal anti-inflammatory drug (NSAID)** with a relatively wide therapeutic window. - Its primary concerns are gastrointestinal and renal side effects rather than toxicity from a narrow therapeutic range. *Prazosin* - **Prazosin** is an **alpha-1 adrenergic blocker** used for hypertension and benign prostatic hyperplasia, and it generally has a wide therapeutic range. - The main concern with prazosin is **first-dose phenomenon** (orthostatic hypotension), which is an initial effect rather than toxicity from a narrow therapeutic window.
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