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 an excessive amount of a drug, leading to harmful effects on the body. This can happen due to overdose or prolonged use beyond the prescribed duration.

2. **Mechanism of Drug Overdose**:
- When a drug is taken, it interacts with specific sites in the body, primarily enzymes. The drug can bind to these enzymes at their active sites or allosteric sites.

3. **Active and Allosteric Sites**:
- The active site of an enzyme is where the substrate binds and the reaction occurs. Allosteric sites are different locations on the enzyme where molecules can bind and affect the enzyme's activity.

4. **Effects of Binding**:
- If a drug binds to the allosteric site, it can change the shape of the enzyme (conformational change), which may lead to the active site being deformed or blocked. This can prevent the enzyme from functioning properly.

5. **Irreversible Changes**:
- In cases of drug-induced poisoning, the binding can be irreversible, meaning that the enzyme's active site is permanently altered. This leads to a loss of enzyme activity and can result in severe side effects or toxicity.

6. **Conclusion**:
- The reason for drug-induced poisoning is primarily due to the irreversible binding of drugs at allosteric sites or active sites of enzymes, leading to permanent changes in enzyme function.