Question:
Which drug is cholinesterase reactivator?
Which drug is cholinesterase reactivator?
Show Hint
When organophosphate poisons (like insecticides or nerve agents) bind to the enzyme acetylcholinesterase, they phosphorylate it and switch it off.
Updated On: Jun 24, 2026
- Donepezil
- Ambenonium chloride
- Physostigmine
- Pralidoxime chloride
Show Solution
Verified By Collegedunia
The Correct Option is D
Solution and Explanation
Concept:
When organophosphate poisons (like insecticides or nerve agents) bind to the enzyme acetylcholinesterase, they phosphorylate it and switch it off. A cholinesterase reactivator is a drug that pulls that phosphate group off and brings the enzyme back to life.
Step 1: Pralidoxime (2-PAM) carries an oxime group (=N–OH) that attacks the phosphorus atom bound to the enzyme, cleaving it away and freeing the active site.
Step 2: This makes pralidoxime the classic antidote used in organophosphate poisoning to reactivate the blocked enzyme.
Why the others are wrong: Donepezil, ambenonium and physostigmine are themselves cholinesterase inhibitors — they block the enzyme rather than reactivate it. Only pralidoxime regenerates the enzyme.
Answer: Option (4) — Pralidoxime chloride.
When organophosphate poisons (like insecticides or nerve agents) bind to the enzyme acetylcholinesterase, they phosphorylate it and switch it off. A cholinesterase reactivator is a drug that pulls that phosphate group off and brings the enzyme back to life.
Step 1: Pralidoxime (2-PAM) carries an oxime group (=N–OH) that attacks the phosphorus atom bound to the enzyme, cleaving it away and freeing the active site.
Step 2: This makes pralidoxime the classic antidote used in organophosphate poisoning to reactivate the blocked enzyme.
Why the others are wrong: Donepezil, ambenonium and physostigmine are themselves cholinesterase inhibitors — they block the enzyme rather than reactivate it. Only pralidoxime regenerates the enzyme.
Answer: Option (4) — Pralidoxime chloride.
Was this answer helpful?
0
0
Top TS PGECET Pharmacy Questions
- Increase in the solubility of the aqueous systems by adding large amount of additives is known as.........
- Clark's formula………
- One of the following is used as a key ingredient in hair conditioning product
- Empty capsule has moisture content in the range of ………
- Aerosol container must withstand pressures as high as 140–180 psi at ………
View More Questions
Top TS PGECET Pharmacology Questions
- Clark's formula………
- What is the final product of purine metabolism in humans?
- In type 2 diabetes mellitus, pancreatic beta cells initially respond to insulin resistance by………
- Underlying mechanism for variant angina is………
- The physiologic effect of PGF2-ALFA
View More Questions
Top TS PGECET Questions
- If \( P = \begin{pmatrix} 1 & 1 & 1 \\ 0 & 1 & 2 \\ 0 & 0 & 1 \end{pmatrix} \) is the modal matrix of \( A = \begin{pmatrix} 1 & 1 & 0 \\ 0 & 2 & 2 \\ 0 & 0 & 3 \end{pmatrix} \) then the sum of all the elements of \( P^{-1}AP \) is
- If the system of equations \( kx + y + z = k - 1 \), \( x + ky + z = k - 1 \), and \( x + y + kz = k - 1 \) has infinite solutions, then \( k \) is
- The value of the integral \( \int_C (2xy - x^2) \, dx + (x^2 + y^2) \, dy \) where \( C \) is the boundary of the region enclosed by \( y = x^2 \) and \( y^2 = x \), described in the positive sense, is
- Let \( f(x) = \log x \). The number \( C \) strictly between \( e^2 \) and \( e^3 \) such that its reciprocal is equal to \( \frac{f(e^3) - f(e^2)}{e^3 - e^2} \) is
- The solution of the differential equation \( (D^2 + 2)y = x^2 \) is
View More Questions