Drug interactions
Carbidopa-levodopa + Methyldopa
Severity: Moderate
Carbidopa-levodopa and Methyldopa: 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
Methyldopa and levodopa compete in dopamine metabolism, and the combination can add to hypotension. Reports also describe CNS effects such as psychiatric disturbance, and methyldopa may alter levodopa effect.
What this interaction means in plain words
Carbidopa-levodopa and Methyldopa 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-levodopa belongs to Central Nervous System; Methyldopa belongs to Cardiovascular.
Why it happens
Additive hypotension, with methyldopa interfering with catecholamine synthesis and sharing the decarboxylase pathway with levodopa.
What to do
Monitor blood pressure and mental status when combining. Reduce the antihypertensive dose if hypotension occurs and consider another agent if psychiatric symptoms develop.
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-levodopa
- Carbidopa-levodopa + Isocarboxazid Contraindicated
- Carbidopa-levodopa + Phenelzine Contraindicated
- Carbidopa-levodopa + Selegiline transdermal Contraindicated
- Carbidopa-levodopa + Tranylcypromine Contraindicated
- Amisulpride + Carbidopa-levodopa Major
- Asenapine + Carbidopa-levodopa Major
Other interactions of Methyldopa
- Methyldopa + Tranylcypromine Contraindicated
- Iobenguane i + Methyldopa Major
- Lofexidine + Methyldopa Major
- Methyldopa + Pexidartinib Major
- Methyldopa + Pretomanid Major
- Methyldopa + Thioridazine Major
Frequently asked questions
Can I take Carbidopa-levodopa with Methyldopa?
MediHelp rates the interaction as moderate. Carbidopa-levodopa and Methyldopa 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. Methyldopa and levodopa compete in dopamine metabolism, and the combination can add to hypotension. Reports also describe CNS effects such as psychiatric disturbance, and methyldopa may alter levodopa effect.
How serious is the interaction between Carbidopa-levodopa and Methyldopa?
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 blood pressure and mental status when combining. Reduce the antihypertensive dose if hypotension occurs and consider another agent if psychiatric symptoms develop.
What other medicines interact with Carbidopa-levodopa?
MediHelp also lists interactions of Carbidopa-levodopa with, for example, Isocarboxazid, Phenelzine, Selegiline transdermal. The full list is on the Carbidopa-levodopa page.
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