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All the following statements regarding interactions of levodopa are correct except
|A||In Parkinsonism, phenothiazines reduce its efficacy|
|B||It is a prodrug|
|C||Pyridoxine reduces effect of levodopa in Parkinsonism|
|D||Domperidone blocks levodopa induced emesis and its therapeutic potential.|
Ans. D Domperidone blocks levodopa induced emesis and its therapeutic potential
- Domperidone decreases the vomiting due to levo-dopa without interfering with its therapeutic action. Because domperidone can not cross BBB, it does not inhibit the D2 receptors in the brain but as CTZ is present outside BBB, it can inhibit the emetogenic potential of levo-dopa.
- L-dopa is a prodrug that acts by conversion to dopamine in the brain.
- Phenothiazines and other D2 blockers that can cross BBB will interfere with therapeutic actions of levo-dopa.
- Pyridoxine decreases the efficiency of l-dopa therapy as discussed earlier.