The reason for “drug induced poisoning” is :

Options

A. Binding irreversibly to the active site of the enzyme
B. Binding at the allosteric sites of the enzyme
C. Binding reversibly at the active site of the enzyme
D. Bringing conformational change in the binding site of enzyme

Answer

### Step-by-Step Solution:

1. **Understanding Drug-Induced Poisoning**:
- Drug-induced poisoning occurs when a person takes a drug in excess of the prescribed dosage, leading to harmful effects on the body.
- It can happen due to prolonged use or overdose of medications.

2. **Mechanism of Drug-Induced Poisoning**:
- When drugs are taken, they interact with enzymes in the body. Each enzyme has an active site where the substrate binds to facilitate a reaction.
- Some drugs can also bind to allosteric sites, which are different from the active site. These sites can modulate the activity of the enzyme.

3. **Effects of Drug Overdose**:
- Continuous or excessive intake of a drug can lead to the binding of the drug to allosteric sites, which can alter the enzyme's structure.
- This alteration can cause the active site to become deformed or blocked, preventing normal enzymatic activity.

4. **Consequences of Enzyme Alteration**:
- The irreversible binding of drugs to the active site or allosteric sites can lead to permanent changes in enzyme function.
- This can result in various side effects and potentially fatal conditions due to the disruption of normal metabolic processes.

5. **Conclusion**:
- Therefore, the reason for drug-induced poisoning is primarily due to the irreversible binding of drugs at the allosteric sites of enzymes, leading to permanent changes in enzyme activity.

### Final Answer:
The correct answer is that drug-induced poisoning is caused by binding at the allosteric sites of the enzyme, leading to irreversible changes.

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