Why is the catechol-O-methyltransferase (COMT) inhibitor added to carbidopa-levodopa therapy? To increase plasma levels To slow the rate of metabolism To improve memory and motor speed To provide relief from excessive acetylcholine

Question

UpStudy AI · Accepted Answer

The primary reason for adding a **catechol-O-methyltransferase (COMT) inhibitor** to **carbidopa-levodopa** therapy is:

**To slow the rate of metabolism**

### Explanation:

- **COMT Inhibitors** (such as entacapone and tolcapone) work by inhibiting the **catechol-O-methyltransferase** enzyme, which is responsible for the breakdown of **levodopa** in the body.
- By slowing the metabolism of levodopa, **COMT inhibitors increase the availability and duration** of levodopa in the bloodstream, allowing more of it to reach the brain where it can be converted to dopamine.
- This enhancement helps improve **motor symptoms** in patients with Parkinson's disease and allows for more consistent symptom control.

### Why Other Options Are Less Appropriate:

1. **To increase plasma levels:** While COMT inhibitors do help maintain higher plasma levels of levodopa, the primary mechanism is by slowing its metabolism rather than directly increasing its concentration.
   
2. **To improve memory and motor speed:** Although improving motor symptoms is a clinical outcome, the specific reason for adding a COMT inhibitor is to slow metabolism, which in turn contributes to motor symptom control.
   
3. **To provide relief from excessive acetylcholine:** This is unrelated to the function of COMT inhibitors or the carbidopa-levodopa therapy.

### Correct Answer:

**To slow the rate of metabolism**
To slow the rate of metabolism

Why is the catechol-O-methyltransferase (COMT) inhibitor added to carbidopa-levodopa therapy? To increase plasma levels To slow the rate of metabolism To improve memory and motor speed To provide relief from excessive acetylcholine

Real Tutor Solution

Answer

Solution

The Deep Dive

Related Questions

Latest Medicine Questions