Drug interactions
Carbidopa + Selegiline
Severity: Moderate
Carbidopa and Selegiline: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Carbidopa is given with levodopa, and adding selegiline can cause marked orthostatic hypotension in some patients. The effect is mainly seen with the levodopa/carbidopa combination rather than carbidopa alone. Selegiline is used in Parkinson disease with levodopa, so the combination is common and usually manageable.
What this interaction means in plain words
Carbidopa and Selegiline can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Carbidopa belongs to Central Nervous System; Selegiline belongs to Central Nervous System.
Why it happens
Selegiline inhibits MAO-B and enhances dopaminergic effects of levodopa, which can add to hypotensive effects of dopaminergic therapy.
What to do
Monitor supine and standing blood pressure when starting or adjusting selegiline with carbidopa/levodopa, and consider reducing the levodopa dose if symptomatic hypotension occurs. Keep selegiline at or below the MAO-B selective dose.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Carbidopa
Other interactions of Selegiline
- Amitriptyline + Selegiline Contraindicated
- Amoxapine + Selegiline Contraindicated
- Atomoxetine + Selegiline Contraindicated
- Benzphetamine + Selegiline Contraindicated
- Brimonidine + Selegiline Contraindicated
- Buprenorphine long-acting + Selegiline Contraindicated
Frequently asked questions
Can I take Carbidopa with Selegiline?
MediHelp rates the interaction as moderate. Carbidopa and Selegiline can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Carbidopa is given with levodopa, and adding selegiline can cause marked orthostatic hypotension in some patients. The effect is mainly seen with the levodopa/carbidopa combination rather than carbidopa alone. Selegiline is used in Parkinson disease with levodopa, so the combination is common and usually manageable.
How serious is the interaction between Carbidopa and Selegiline?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor supine and standing blood pressure when starting or adjusting selegiline with carbidopa/levodopa, and consider reducing the levodopa dose if symptomatic hypotension occurs. Keep selegiline at or below the MAO-B selective dose.
What other medicines interact with Carbidopa?
MediHelp also lists interactions of Carbidopa with, for example, Metoclopramide, Amlodipine-atorvastatin, Amlodipine-benazepril. The full list is on the Carbidopa page.
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