Does Phenothiazines Interact with Levodopa?
Moderate interaction. Phenothiazines (dopamine D2 receptor antagonists) may reduce the effectiveness of levodopa. Monitor patients for worsening Parkinson's symptoms.
Source & how this summary was prepared
This interaction summary was extracted from FDA drug labeling through openFDA, using automated processing and AI assistance. NIH/NLM RxNorm helps organize drug names.
Read the saved source label on DailyMed →
A separate current-label comparison has not been recorded for this page. Read about our extraction process.
- Interaction classification
- Moderate
- Levodopa Class
- Aromatic Amino Acid
- Management
- Confirm exact products with your pharmacist
- Data Source
- U.S. FDA via OpenFDA
How this interaction works
Dopamine D2 receptor antagonism
What To Tell Your Doctor or Pharmacist
If you are taking Phenothiazines and your doctor is considering prescribing Levodopa (or vice versa), make sure to:
- Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
- Ask whether the benefits of combining these medications outweigh the risks for your specific situation
- Ask what symptoms to watch for that would indicate the interaction is causing problems
- Ask whether any dosage adjustments are needed
- Never stop or change either medication without first consulting your healthcare provider