Drug interactions
Carbidopa + Metolazone
Severity: Moderate
Carbidopa and Metolazone: 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 given with levodopa can cause orthostatic hypotension, which may add to the blood-pressure-lowering effect of metolazone. Patients may need antihypertensive dose adjustment when levodopa therapy starts.
What this interaction means in plain words
Carbidopa and Metolazone 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; Metolazone belongs to Cardiovascular.
Why it happens
Additive hypotensive effect from levodopa-derived dopaminergic activity and diuretic volume reduction.
What to do
Monitor blood pressure including orthostatic readings when starting or adjusting levodopa/carbidopa, and reduce the antihypertensive dose if hypotension develops.
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 Metolazone
Other interactions of Carbidopa
Frequently asked questions
Can I take Carbidopa with Metolazone?
MediHelp rates the interaction as moderate. Carbidopa and Metolazone 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 given with levodopa can cause orthostatic hypotension, which may add to the blood-pressure-lowering effect of metolazone. Patients may need antihypertensive dose adjustment when levodopa therapy starts.
How serious is the interaction between Carbidopa and Metolazone?
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 including orthostatic readings when starting or adjusting levodopa/carbidopa, and reduce the antihypertensive dose if hypotension develops.
What other medicines interact with Metolazone?
MediHelp also lists interactions of Metolazone with, for example, Amifostine, Amlodipine-hydrochlorothiazide-valsartan, Amlodipine-olmesartan-hydrochlorothiazide. The full list is on the Metolazone page.
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