Serotonin Syndrome — MCQs
Treatment of malignant hyperthermia is
All of the following are selective indications for the use of hypotonic solutions, except:
What neurotransmitter is mainly involved in obsessive-compulsive disorder (OCD)?
A medical student presented to the ED with protracted vomiting. For this he was given an anti-emetic drug following which he developed abnormal posturing. Which of the following is the most likely drug to be given to the patient?
Match the following drugs in Column A with their contraindications in Column B. | Column A | Column B | | :-- | :-- | | 1. Morphine | 1. QT prolongation | | 2. Amiodarone | 2. Thromboembolism | | 3. Vigabatrin | 3. Pregnancy | | 4. Estrogen preparations | 4. Head injury |
Which of the following are the causes of retroperitoneal fibrosis?
What is the first-line treatment for generalized anxiety disorder?
A patient has been a known alcoholic for the last 20 years. He suddenly develops restlessness, tremors, and agitation. What is the most likely diagnosis?
Which is NOT a common symptom of opioid withdrawal?
Which of the following is false regarding parasuicide?
Serotonin Syndrome Indian Medical PG Practice Questions and MCQs
Question 1: Treatment of malignant hyperthermia is
- A. Propranolol
- B. Dantrolene (Correct Answer)
- C. Halothane
- D. Nitrous oxide
Explanation: ***Dantrolene*** - **Dantrolene** is a **ryanodine receptor antagonist** that blocks calcium release from the sarcoplasmic reticulum in muscle cells, directly addressing the underlying pathophysiology of malignant hyperthermia. - Administration of dantrolene is the **first-line and specific treatment** for malignant hyperthermia, rapidly reversing its life-threatening symptoms. *Propranolol* - **Propranolol** is a **beta-blocker** primarily used to treat hypertension, angina, and arrhythmias, by reducing heart rate and contractility. - It does not have any direct action on the **ryanodine receptors** or the excessive calcium release responsible for the muscle rigidity and hypermetabolism seen in malignant hyperthermia. *Halothane* - **Halothane** is an **inhalational anesthetic** that is a well-known trigger of malignant hyperthermia, particularly in genetically susceptible individuals. - Administering halothane would **exacerbate** malignant hyperthermia due to its potent ability to induce uncontrolled calcium release from the sarcoplasmic reticulum. *Nitrous oxide* - **Nitrous oxide** is an **inhalational anesthetic** that is generally considered a weak trigger for malignant hyperthermia and is often used in combination with other agents. - While typically considered safe regarding malignant hyperthermia, it does not possess any therapeutic properties to treat the condition and would not be used once malignant hyperthermia is suspected.
Question 2: All of the following are selective indications for the use of hypotonic solutions, except:
- A. Burns (Correct Answer)
- B. Free water deficit
- C. Hypernatremia
- D. Maintenance fluid therapy in stable patients
Explanation: ***Burns*** - **Hypotonic solutions** are generally *not* indicated for burn patients because these patients typically lose large amounts of **isotonic fluid** through damaged skin. [1] - The primary goal in burn resuscitation is to replace lost plasma volume with **isotonic crystalloids** (e.g., Lactated Ringer's) to prevent **hypovolemic shock**. [1] *Hypernatremia* - **Hypernatremia** is a condition of excess sodium relative to water, meaning the body has a **water deficit**. [1] - **Hypotonic solutions** are used to gradually lower serum sodium by providing **free water** to dilute the excess sodium. *Free water deficit* - A **free water deficit** indicates a lack of pure water relative to solutes, leading to increased plasma osmolality. [2] - **Hypotonic solutions** are specifically designed to provide **free water** to correct this deficit and restore proper fluid balance. *Maintenance fluid therapy in stable patients* - For stable patients requiring maintenance fluids, **hypotonic solutions** (e.g., D5W with 0.45% NS) are often used to cover obligatory fluid losses and provide adequate water without causing **sodium overload**. [1] - In such cases, the goal is to prevent dehydration and electrolyte imbalances over time, which often requires a balance of electrolytes and **free water**. [1]
Question 3: What neurotransmitter is mainly involved in obsessive-compulsive disorder (OCD)?
- A. GABA
- B. NE
- C. Dopamine
- D. Serotonin (Correct Answer)
Explanation: ***Serotonin*** - The **serotonin system** is consistently implicated in the pathophysiology of OCD, and selective serotonin reuptake inhibitors (**SSRIs**) are the first-line pharmacotherapy. - Dysregulation in **serotonin levels** and receptor function is thought to contribute to the repetitive thoughts and compulsive behaviors characteristic of the disorder. *GABA* - **Gamma-aminobutyric acid (GABA)** is the primary inhibitory neurotransmitter in the brain and is mainly associated with anxiety disorders. - While anxiety is often comorbid with OCD, GABA dysregulation is not considered the primary neurochemical basis for the core symptoms of OCD. *NE* - **Norepinephrine (NE)** is a neurotransmitter involved in the 'fight or flight' response, attention, and mood. - While NE imbalances can contribute to anxiety and mood disorders, it is not considered the main neurotransmitter primarily implicated in the core pathology of OCD. *Dopamine* - **Dopamine** is mainly associated with reward, motivation, and motor control, and plays a role in conditions like schizophrenia and Parkinson's disease. - While dopamine has a **significant secondary role** in OCD (especially in the cortico-striato-thalamo-cortical circuits) and dopamine antagonists are used as augmentation therapy in treatment-resistant cases, **serotonin remains the primary neurotransmitter** implicated in OCD pathophysiology.
Question 4: A medical student presented to the ED with protracted vomiting. For this he was given an anti-emetic drug following which he developed abnormal posturing. Which of the following is the most likely drug to be given to the patient?
- A. Ondansetron
- B. Domperidone
- C. Dexamethasone
- D. Metoclopramide (Correct Answer)
Explanation: ***Metoclopramide*** - **Metoclopramide** is a **dopamine D2 receptor antagonist** that can cause **extrapyramidal symptoms (EPS)**, such as abnormal posturing (dystonia), due to its central action. - This adverse effect is more common with higher doses or in susceptible individuals, and the scenario directly describes it as a consequence of the antiemetic. *Ondansetron* - **Ondansetron** is a **5-HT3 receptor antagonist** primarily used for nausea and vomiting, particularly chemotherapy-induced. - It works **peripherally and centrally** but its side effect profile does not typically include extrapyramidal symptoms like abnormal posturing. *Domperidone* - **Domperidone** is also a **dopamine D2 receptor antagonist**, but it has **limited penetration across the blood-brain barrier**. - Due to its predominantly peripheral action, it causes **fewer central nervous system side effects**, including extrapyramidal symptoms, compared to metoclopramide. *Dexamethasone* - **Dexamethasone** is a **corticosteroid** with antiemetic properties, often used in conjunction with other antiemetics, especially in chemotherapy. - Its mechanism is not related to dopamine receptors, and it **does not typically cause extrapyramidal symptoms or abnormal posturing**.
Question 5: Match the following drugs in Column A with their contraindications in Column B. | Column A | Column B | | :-- | :-- | | 1. Morphine | 1. QT prolongation | | 2. Amiodarone | 2. Thromboembolism | | 3. Vigabatrin | 3. Pregnancy | | 4. Estrogen preparations | 4. Head injury |
- A. A-1, B-3, C-2, D-4
- B. A-4, B-1, C-3, D-2 (Correct Answer)
- C. A-3, B-2, C-4, D-1
- D. A-2, B-4, C-1, D-3
Explanation: ***A-4, B-1, C-3, D-2*** - **Morphine** is contraindicated in **head injury** as it can increase intracranial pressure and mask neurological symptoms. - **Amiodarone** is contraindicated in patients with **QT prolongation** due to its risk of inducing more severe arrhythmias like Torsades de Pointes. - **Vigabatrin** is contraindicated during **pregnancy** due to its potential for teratogenicity and adverse effects on fetal development. - **Estrogen preparations** are contraindicated in patients with a history of **thromboembolism** due to their increased risk of blood clot formation. *A-1, B-3, C-2, D-4* - This option incorrectly matches **Morphine** with QT prolongation and **Estrogen preparations** with head injury, which are not their primary contraindications. - It also incorrectly links **Vigabatrin** with thromboembolism and **Amiodarone** with pregnancy. *A-3, B-2, C-4, D-1* - This choice incorrectly associates **Morphine** with pregnancy and **Vigabatrin** with head injury, which are not the most critical or direct contraindications. - It also misaligns **Amiodarone** with thromboembolism and **Estrogen preparations** with QT prolongation. *A-2, B-4, C-1, D-3* - This option incorrectly matches **Morphine** with thromboembolism and **Amiodarone** with head injury, which are not their most significant contraindications. - It also incorrectly links **Vigabatrin** with QT prolongation and **Estrogen preparations** with pregnancy.
Question 6: Which of the following are the causes of retroperitoneal fibrosis?
- A. Lymphoma
- B. Carcinoid tumours
- C. Drugs (Correct Answer)
- D. Continuous Ambulatory Peritoneal Dialysis (CAPD)
Explanation: ***Drugs*** - Various medications can induce retroperitoneal fibrosis, including **methysergide**, **beta-blockers**, and some **antibiotics**. - Drug-induced retroperitoneal fibrosis often resolves with **discontinuation of the offending agent**. *Lymphoma* - While lymphoma can cause retroperitoneal masses, it typically presents with distinct features such as **lymphadenopathy** and **B symptoms** (fever, night sweats, weight loss) rather than generalized fibrosis [1]. - Lymphoma involves neoplastic proliferation of lymphocytes, leading to **mass effect** and infiltration, which is distinct from the fibrotic process [1]. *Carcinoid tumours* - Carcinoid tumors can cause fibrosis, but typically in the **pericardium** or **pleura** (carcinoid heart disease) or **mesenterium**, not the retroperitoneum directly as a primary cause in this context. - The fibrosis associated with carcinoid syndrome is due to the release of **serotonin** and other vasoactive substances. *Continuous Ambulatory Peritoneal Dialysis (CAPD)* - CAPD can lead to **peritoneal fibrosis** (sclerosing encapsulating peritonitis), which affects the peritoneum lining the abdominal cavity, not the retroperitoneum. - This complication is distinct from retroperitoneal fibrosis and involves changes to the **peritoneal membrane**, often due to bio-incompatible dialysate.
Question 7: What is the first-line treatment for generalized anxiety disorder?
- A. SSRIs (Correct Answer)
- B. Antipsychotics
- C. Benzodiazepines
- D. MAO inhibitors
Explanation: ***SSRIs*** - **Selective Serotonin Reuptake Inhibitors (SSRIs)** are considered first-line pharmacological treatment for generalized anxiety disorder due to their efficacy and generally favorable side effect profile. - They work by increasing the levels of **serotonin** in the brain, which helps regulate mood and anxiety symptoms. *Antipsychotics* - **Antipsychotics** are primarily used to treat psychotic disorders like schizophrenia or severe mood disorders with psychotic features, not typically as first-line for generalized anxiety disorder. - Their significant side effect profile, including metabolic disturbances and movement disorders, makes them a less desirable choice for initial treatment of anxiety. *Benzodiazepines* - While effective for acute anxiety relief, **benzodiazepines** are generally not considered first-line for long-term management of GAD due to the risk of dependence, tolerance, and withdrawal symptoms. - They are often used for short-term relief or as an adjunct in the initial phase of treatment while awaiting the therapeutic effects of SSRIs. *MAO inhibitors* - **Monoamine Oxidase Inhibitors (MAOIs)** are older antidepressants with significant drug-drug and drug-food interactions (e.g., tyramine crisis), making them usually a last-resort treatment for severe mood disorders, not generalized anxiety disorder. - Their complex dietary restrictions and side effect profile preclude their use as a first-line option.
Question 8: A patient has been a known alcoholic for the last 20 years. He suddenly develops restlessness, tremors, and agitation. What is the most likely diagnosis?
- A. Alcoholic hallucinosis
- B. Wernicke's encephalopathy
- C. Korsakoff's syndrome
- D. Delirium tremens (Correct Answer)
Explanation: ***Delirium tremens*** - This condition is characterized by **restless tremors**, **agitation**, and often hallucinations, occurring in chronic alcoholics after sudden cessation or reduction of alcohol intake. - The symptoms typically appear **48-96 hours** after the last drink and can include severe autonomic hyperactivity such as tachycardia, hypertension, and hyperthermia. *Alcoholic hallucinosis* - This involves vivid auditory, visual, or tactile hallucinations that occur in a **clear sensorium**, typically 12-48 hours after decreased alcohol intake. - Unlike delirium tremens, there is usually **no significant disorientation** or severe autonomic instability. *Wernicke's encephalopathy* - This is an acute neurological condition due to **thiamine deficiency**, common in chronic alcoholics, presenting with the classical triad of **ocular disturbances** (nystagmus, ophthalmoplegia), **ataxia**, and **confusion**. - While confusion can be present, the primary symptoms described (restless tremors, agitation) are not the hallmark features. *Korsakoff's syndrome* - This is a chronic neuropsychiatric disorder that often follows untreated Wernicke's encephalopathy, characterized by **severe memory impairment** (anterograde and retrograde amnesia) and **confabulation**. - It primarily affects memory and learning, rather than acute agitation and tremors.
Question 9: Which is NOT a common symptom of opioid withdrawal?
- A. Seizures (Correct Answer)
- B. Yawning
- C. Insomnia
- D. Diarrhea
Explanation: ***Seizures*** - Seizures are **not typical** of opioid withdrawal; they are more characteristic of withdrawal from substances like **alcohol** or **benzodiazepines**. - Opioid withdrawal symptoms are primarily **autonomic** and **flu-like**, not neurological in the sense of causing seizures. *Yawning* - **Frequent yawning** is a common and early **autonomic symptom** of opioid withdrawal, indicating central nervous system overactivity. - It is often accompanied by other signs of hyperarousal and discomfort. *Insomnia* - **Insomnia** (difficulty sleeping) is a very common and distressing symptom during opioid withdrawal due to heightened central nervous system activity and generalized discomfort. - Patients often experience **restlessness** and an inability to achieve restful sleep. *Diarrhea* - **Diarrhea** is a prominent gastrointestinal symptom of opioid withdrawal, resulting from the cessation of opioid-induced slowing of gut motility. - This symptom reflects the **autonomic hyperactivity** caused by opioid cessation.
Question 10: Which of the following is false regarding parasuicide?
- A. Also known as attempted suicide.
- B. Mostly seen in psychological disturbances.
- C. A conscious, impulsive, manipulative act to get rid of an intolerable situation.
- D. Hanging is the most common form. (Correct Answer)
Explanation: **Explanation:** **Parasuicide** (also known as Deliberate Self-Harm) refers to a non-fatal act in which an individual deliberately causes self-injury or ingests a substance in excess of the prescribed dosage. **Why Option D is the correct answer (False statement):** Hanging is the most common method used in **completed suicides**, not parasuicide. In parasuicide, the intent is often not to die but to communicate distress or manipulate a situation. Therefore, the methods chosen are usually less lethal and allow for intervention. The most common method of parasuicide is **self-poisoning** (e.g., drug overdose or pesticide ingestion) or **superficial wrist cutting**. **Analysis of other options:** * **Option A:** Parasuicide is synonymous with **attempted suicide**, though the term is specifically used for acts where the intent to die is low or ambiguous. * **Option B:** It is frequently seen in individuals with **psychological disturbances**, most notably **Borderline Personality Disorder**, depression, and substance abuse. * **Option C:** It is often a **conscious and impulsive act**. It is frequently described as "manipulative" (or a "cry for help") because the goal is often to escape an intolerable emotional state or to influence the behavior of others. **High-Yield Clinical Pearls for NEET-PG:** * **Gender:** Parasuicide is more common in **females**, whereas completed suicide is more common in **males** (Gender Paradox). * **Age:** Most common in the younger age group (15–30 years). * **Strongest Predictor:** A previous history of parasuicide is the strongest predictor of a future completed suicide. * **SAD PERSONS Scale:** Used to assess the risk of suicide in clinical settings.
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