Emergency Pharmacology Practice Questions

Q: A patient presents to the emergency department after receiving a penicillin injection and is diagnosed with anaphylactic shock. Which of the following is the most critical life-saving measure for immediate treatment?

Intramuscular adrenaline hydrochloride. **Explanation:** The drug of choice for anaphylactic shock is **Adrenaline (Epinephrine)**. In an emergency setting, the **Intramuscular (IM)** route is the gold standard for initial treatment. **1. Why Option C is Correct:** * **Rapid Absorption:** The vastus lateralis (anterolateral thigh) is highly vascular, ensuring faster peak plasma concentrations compared to the subcutaneous route. * **Safety Profile:** IM administration is safer than IV for initial management as it carries a lower risk of inducing fatal arrhythmias or severe hypertension, which can occur with rapid IV boluses. * **Mechanism:** Adrenaline acts as a physiological antagonist to histamine. Its **α1-agonist** effect causes vasoconstriction (reversing hypotension and mucosal edema), while its **β2-agonist** effect causes bronchodilation. **2. Why Other Options are Incorrect:** * **Option A (IV Hydrocortisone):** Corticosteroids have a slow onset of action (4–6 hours). They are used to prevent "biphasic reactions" (delayed recurrence) but are not life-saving in the acute phase. * **Option B (IV Adrenaline):** This is reserved for patients in profound shock or cardiac arrest who are unresponsive to multiple IM doses. It must be given under cardiac monitoring and in a diluted form (1:10,000). * **Option D (IV Glucose Saline):** While fluid resuscitation is important, it is secondary to the administration of adrenaline. **High-Yield Clinical Pearls for NEET-PG:** * **Standard Dose:** 0.5 mg (0.5 ml of 1:1000 concentration) IM in adults. * **Pediatric Dose:** 0.01 mg/kg (max 0.3 mg) IM. * **Site:** Mid-outer thigh (Vastus lateralis). * **Concentration Ratios:** * **1:1,000** for IM use. * **1:10,000** for IV use (Cardiac arrest).

Q: Which of the following statements regarding the use of adrenaline in anaphylactic shock is TRUE?

The usual dose is 0.5-1 mg by IM route.. ### Explanation **1. Why Option A is Correct:** Adrenaline (Epinephrine) is the drug of choice for anaphylactic shock. In adults, the standard dose is **0.5 mg (0.5 mL of 1:1000 solution)** administered via the **Intramuscular (IM)** route in the anterolateral thigh. The IM route is preferred over subcutaneous (SC) because it achieves higher and faster peak plasma concentrations, which is critical in a life-threatening emergency. **2. Analysis of Incorrect Options:** * **Option B:** While rare, **cerebral hemorrhage** and cardiac arrhythmias are known potential adverse effects of adrenaline, particularly if it is administered rapidly via the IV route or in patients with underlying hypertension. * **Option C:** Adrenaline has a very short half-life. In anaphylaxis, if the patient does not improve, the dose should be repeated every **5 to 15 minutes**, not every 2–4 hours. * **Option D:** The concentrations differ significantly. The **1:1000 (1 mg/mL)** solution is used for IM injection. For **Intravenous (IV)** use, this must be diluted to **1:10,000 (0.1 mg/mL)** to prevent fatal arrhythmias or severe hypertension. **3. High-Yield Clinical Pearls for NEET-PG:** * **Mechanism of Action:** $\alpha_1$ (vasoconstriction to reduce edema/hypotension), $\beta_1$ (positive inotropy/chronotropy), and $\beta_2$ (bronchodilation and stabilization of mast cells). * **Pediatric Dose:** 0.01 mg/kg (up to a max of 0.3 mg) IM. * **Best Site:** Vastus lateralis (lateral thigh) due to high vascularity. * **Refractory Cases:** If the patient is on **Beta-blockers** and does not respond to adrenaline, the antidote/alternative is **Glucagon**.

Q: A patient presented with anaphylactic reactions developed angioedema. What is the drug of choice for treating this condition?

Adrenaline. **Explanation:** **Adrenaline (Epinephrine)** is the drug of choice for anaphylaxis and associated angioedema because it acts as a **physiological antagonist** to histamine and other inflammatory mediators [1]. Its mechanism of action addresses all life-threatening components of anaphylaxis: * **$\alpha_1$ agonist effect:** Causes vasoconstriction, which reduces mucosal edema (treating angioedema) and increases peripheral vascular resistance to combat hypotension [1], [2]. * **$eta_1$ agonist effect:** Increases cardiac output (positive inotropy and chronotropy). * **$eta_2$ agonist effect:** Causes potent bronchodilation and inhibits further mast cell degranulation [2]. **Why other options are incorrect:** * **Corticosteroids (e.g., Hydrocortisone):** These have a slow onset of action (4–6 hours). They are used to prevent "biphasic reactions" (delayed recurrence of symptoms) but are not effective for the acute, life-threatening phase. * **Antihistaminics (e.g., Pheniramine):** These are slow-acting and only compete for H1 receptors. They do not reverse bronchospasm or hypotension and are considered secondary treatments [3]. * **Sodium Cromoglycate:** This is a mast cell stabilizer used for **prophylaxis** of asthma or allergic rhinitis. It is ineffective once degranulation has already occurred. **High-Yield Clinical Pearls for NEET-PG:** * **Route of Choice:** Intramuscular (IM) in the anterolateral thigh is preferred over SC or IV in initial management due to faster and more reliable absorption [1]. * **Concentration:** Use **1:1000** for IM and **1:10,000** for IV (reserved for cardiac arrest or profound shock) [1]. * **Standard Dose:** 0.3-0.5 mg (0.3-0.5 ml of 1:1000) for adults [1]; 0.01 mg/kg for children. * **Drug of Choice for Hereditary Angioedema (Prophylaxis):** Danazol or Stanozolol. (Acute attack: C1 esterase inhibitor concentrate or Icatibant).

Q: Oxygen as an emergency drug is contraindicated in which of the following conditions?

Hyperventilation. **Explanation:** **1. Why Hyperventilation is the Correct Answer:** In acute hyperventilation (often associated with anxiety or panic attacks), the patient breathes rapidly and deeply, leading to the excessive "blowing off" of Carbon Dioxide ($CO_2$). This results in **Respiratory Alkalosis** and a decrease in the partial pressure of arterial $CO_2$ ($PaCO_2$). Administering supplemental oxygen is contraindicated because it does not address the underlying pathology and may further suppress the respiratory drive. The standard treatment is to increase the $CO_2$ levels (e.g., breathing into a paper bag or simple reassurance) to restore the acid-base balance. **2. Analysis of Incorrect Options:** * **Anaphylaxis (A):** This is a medical emergency where laryngeal edema and bronchospasm can cause severe hypoxia. High-flow oxygen is a critical supportive measure alongside Adrenaline. * **Asthma (B):** Acute severe asthma leads to ventilation-perfusion mismatch and hypoxia. Oxygen is indicated to maintain $SpO_2$ between 93-95%. * **COPD (D):** While excessive oxygen can cause CO2 retention in COPD patients (due to the loss of hypoxic drive), oxygen is **not contraindicated**. It must be administered cautiously (controlled oxygen therapy) using a Venturi mask to maintain a target $SpO_2$ of 88-92%. **3. NEET-PG High-Yield Pearls:** * **Hypoxic Drive:** In chronic CO2 retainers (like COPD), the respiratory center becomes insensitive to $CO_2$. Respiration is driven by low $O_2$ levels. Giving 100% $O_2$ can abolish this drive, leading to respiratory arrest. * **Oxygen Toxicity:** Prolonged use of 100% oxygen can lead to absorption atelectasis and Retinopathy of Prematurity (in neonates). * **Drug of Choice for Hyperventilation:** Reassurance and, if necessary, a benzodiazepine (e.g., Diazepam) to reduce anxiety.

Q: What is the drug of choice for anaphylactic shock?

Adrenaline. **Explanation:** **Adrenaline (Epinephrine)** is the drug of choice for anaphylactic shock [2] because it acts as a **physiological antagonist** to histamine and other inflammatory mediators. Its life-saving efficacy stems from its potent action on multiple receptors: [1], [2] * **$\alpha_1$ receptors:** Cause vasoconstriction, which increases peripheral vascular resistance to treat hypotension and reduces mucosal edema (laryngeal edema) [1], [2]. * **$\beta_1$ receptors:** Provide positive inotropic and chronotropic effects, improving cardiac output. * **$\beta_2$ receptors:** Induce bronchodilation and, crucially, **stabilize mast cells**, inhibiting further release of inflammatory mediators [1]. **Why other options are incorrect:** * **Antihistaminics (B):** These are considered **second-line** agents. They only block H1/H2 receptors and do not reverse life-threatening airway obstruction or hypotension. They have a slow onset of action. * **Corticosteroids (C):** These are used to prevent **biphasic reactions** (delayed recurrence of symptoms). They have a slow onset (4–6 hours) and are ineffective in the acute management of cardiovascular collapse. * **Epinephrine (D):** While Epinephrine is the same drug as Adrenaline, in many Indian medical examinations (including traditional NEET-PG patterns), **Adrenaline** is the preferred nomenclature used in standard textbooks like K.D. Tripathi. *Note: In clinical practice, they are synonymous.* **High-Yield Clinical Pearls for NEET-PG:** * **Route of Choice:** Intramuscular (IM) in the **anterolateral thigh** (Vastus lateralis) due to faster absorption and higher plasma levels compared to SC or IM deltoid [2]. * **Concentration:** **1:1000** (1 mg/ml) for IM; **1:10,000** (0.1 mg/ml) for IV [2]. * **Standard Dose:** 0.5 mg (0.5 ml of 1:1000) for adults; 0.01 mg/kg for children [2]. * **Mechanism:** Physiological antagonism.

Q: What is the concentration of adrenaline used in the following route of administration?

1:10,000. ***1:10,000*** - The image depicts **intraosseous (IO) infusion** being administered. For **IV/IO administration during cardiac arrest**, adrenaline is used in a **1:10,000 concentration** (0.1 mg/mL). - This is the standard concentration for resuscitation across all age groups (pediatric and adult) as per **PALS and ACLS guidelines**. - **Pediatric dose:** 0.01 mg/kg (0.1 mL/kg of 1:10,000 solution) IV/IO - **Adult dose:** 1 mg (10 mL of 1:10,000 solution) IV/IO - This concentration allows safe systemic delivery with appropriate cardiovascular effects during cardiac arrest. *1:1000* - The 1:1000 concentration (1 mg/mL) is used for **intramuscular (IM) injection** in the treatment of **anaphylaxis**. - **Dose:** 0.01 mg/kg IM (maximum 0.5 mg in adults, 0.3 mg in children) - This concentration is **too concentrated for direct IV/IO administration** and could cause severe hypertension, arrhythmias, and myocardial ischemia if given undiluted intravenously. *1:100* - A 1:100 concentration (10 mg/mL) is used for **topical application** or mixed with **local anesthetics** (e.g., lidocaine with epinephrine for local anesthesia). - This very high concentration is **never used for systemic administration** and would cause life-threatening cardiovascular complications if given IV/IO. *1:100,000* - The 1:100,000 concentration (0.01 mg/mL) is primarily used **mixed with local anesthetics** for prolonged local/regional anesthesia and hemostasis. - This concentration is **too dilute** for emergency resuscitation and is not the standard for IV/IO administration during cardiac arrest.

Q: Which of the following drugs is not used for the emergency (immediate) management of hyperkalaemia?

Injection MgSO4. ***Injection MgSO4*** - Magnesium sulfate is not a direct treatment for hyperkalaemia; its primary use is for conditions like **eclampsia**, **asthma exacerbations**, or **torsades de pointes**. - It does not directly affect potassium levels or cardiac membrane stability in the context of hyperkalaemia. *10% calcium gluconate over 10 min* - **Calcium gluconate** is used for immediate cardioprotection in hyperkalaemia by stabilizing the **cardiac membrane**, thereby reducing the risk of arrhythmias. - It does not lower serum potassium levels but mitigates the dangerous cardiac effects. *Insulin-dextrose* - This combination is an effective treatment for hyperkalaemia as **insulin** drives potassium from the extracellular to the intracellular space. - **Dextrose** is administered concurrently to prevent hypoglycaemia induced by insulin. *Salbutamol nebulisation* - **Beta-2 agonists** like salbutamol promote the uptake of potassium into cells, thus lowering serum potassium levels. - While effective, its action is generally less rapid and potent than insulin-dextrose or calcium gluconate in severe cases.

Q: Drug used for treatment of scorpion sting is -

Prazosin. ***Prazosin*** - **Prazosin**, an alpha-1 blocker, is the drug of choice for treating **scorpion sting envenomation** due to its ability to counteract the systemic effects like hypertension and myocardial dysfunction. - It works by blocking the effects of excessive catecholamine release caused by the scorpion venom, thereby reducing **vasoconstriction** and improving peripheral circulation. *Adrenaline* - **Adrenaline (epinephrine)** is primarily used in cases of **anaphylaxis** or severe allergic reactions, which are not the typical primary concern in scorpion stings. - Its **vasoconstrictive** and **chronotropic** effects could worsen the cardiovascular complications already present due to scorpion venom. *Morphine* - **Morphine** is a potent **analgesic** used to relieve severe pain. While pain is a symptom of scorpion sting, it does not address the underlying **cardiovascular and systemic effects**. - It can also cause **respiratory depression**, which might complicate the management, especially in severe envenomation. *Captopril* - **Captopril** is an **ACE inhibitor** used primarily for **hypertension** and **heart failure**. - It is not the drug of choice for acute management of scorpion stings as it modulates the **renin-angiotensin system**, which is not the primary mechanism to counteract the venom's effects.

Question 1

A patient presents to the emergency department after receiving a penicillin injection and is diagnosed with anaphylactic shock. Which of the following is the most critical life-saving measure for immediate treatment?

Accepted Answer

Intramuscular adrenaline hydrochloride

Answer

Intravenous hydrocortisone hemisuccinate

Answer

Intravenous adrenaline hydrochloride

Answer

Intravenous glucose saline

Question 2

Which of the following statements regarding the use of adrenaline in anaphylactic shock is TRUE?

Accepted Answer

The usual dose is 0.5-1 mg by IM route.

Answer

Cerebral hemorrhage never occurs as an adverse effect to epinephrine when used in the treatment of anaphylactic shock.

Answer

It is repeated after every 2-4 hours.

Answer

The same solution can be given for subcutaneous as well as intravenous routes.

Question 3

A patient presented with anaphylactic reactions developed angioedema. What is the drug of choice for treating this condition?

Accepted Answer

Adrenaline

Answer

Corticosteroid

Answer

Antihistaminics

Answer

Sodium chromoglycate

Question 4

A young man is prescribed parenteral antibiotics for a respiratory tract infection. He collapses immediately after receiving the first dose, presenting with tachycardia, wheezing, and a drop in blood pressure. What are the most appropriate immediate interventions for this situation?

Accepted Answer

Subcutaneous epinephrine

Answer

Intravenous saline

Answer

Intravenous hydrocortisone

Answer

Nebulized salbutamol

Question 5

Oxygen as an emergency drug is contraindicated in which of the following conditions?

Accepted Answer

Hyperventilation

Answer

Anaphylaxis

Answer

Asthma

Answer

COPD

Question 6

What is the drug of choice for anaphylactic shock?

Accepted Answer

Adrenaline

Answer

Antihistaminic

Answer

Corticosteroids

Answer

Epinephrine

Question 7

What is the concentration of adrenaline used in the following route of administration?

Accepted Answer

1:10,000

Answer

1:100

Answer

1:1000

Answer

1:100,000

Question 8

A 3-year-old child presents with febrile seizures. All are correct about the route of drug administered except:

Accepted Answer

Press the plunger slowly to give the complete prescribed dose

Answer

Call for help, keep airway open and turn to lateral position

Answer

Use midazolam provided in the plastic vial

Answer

Insert mucosal atomizer device loosely into nostril

Question 9

Which of the following drugs is not used for the emergency (immediate) management of hyperkalaemia?

Accepted Answer

Injection MgSO4

Answer

10% calcium gluconate over 10 min

Answer

Insulin-dextrose

Answer

Salbutamol nebulisation

Question 10

Drug used for treatment of scorpion sting is -

Accepted Answer

Prazosin

Answer

Adrenaline

Answer

Morphine

Answer

Captopril

Emergency Pharmacology — MCQs

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