**Question:** Drug used for cobra bite is

A. Antivenom
B. Calcium Chloride
C. Atropine
D. Morphine

**Correct Answer:** A. Antivenom

**Core Concept:**
Snake venoms are complex mixtures of pharmacologically active substances that cause a wide range of physiological effects in humans. The severity and symptoms of a snake bite depend on the venom's composition and the victim's immune response.

**Why the Correct Answer is Right:**
Antivenom is a specific medication used to neutralize the effects of snake venom. It is a preparation containing antibodies (IgG) raised against the venom proteins, which bind to and neutralize the venom toxins, counteracting their effects. Antivenom is specific to the venom of a particular snake species, so the correct antivenom is crucial for effective treatment.

**Why Each Wrong Option is Incorrect:**

**Option B (Calcium Chloride):**
Calcium chloride is used to counteract the effects of snake venom that cause coagulopathy (disruption of blood clotting). However, it is not specific to the venom of a particular snake species and can lead to severe complications like hypercalcemia and hyperkalemia. Therefore, it is not the ideal treatment option for cobra bite.

**Option C (Atropine):**
Atropine is a medication used to counteract the effects of snake venom that cause increased nervous system stimulation (cholinergic crisis). Although it is part of the antidotal regimen for some snakebites, it is not specific to cobra venom and may not be effective in severe cases.

**Option D (Morphine):**
Morphine is an opioid analgesic used for pain relief. It is not specific to cobra venom and does not address the systemic effects of the venom.

**Clinical Pearl:**
In cases of cobra bite, the appropriate treatment involves a combination of antivenom specific to the cobra species and supportive care. The antivenom neutralizes the venom, while supportive care focuses on managing complications like hypotension, respiratory distress, and kidney failure, which may arise due to snake venom effects.