Drug interactions
Methazolamide + Phenytoin
Severity: Minor
Methazolamide and Phenytoin: minor 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
Both phenytoin and carbonic anhydrase inhibitors have been associated with disturbed bone and mineral metabolism. Concurrent long-term use may increase the risk of osteomalacia, mainly with acetazolamide.
What this interaction means in plain words
Methazolamide and Phenytoin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Additive effects on vitamin D and calcium handling and bone metabolism, with metabolic acidosis from carbonic anhydrase inhibition.
What to do
With long-term combined use, monitor calcium, vitamin D status and bone health, and supplement as needed.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Phenytoin
- Artemether / lumefantrine + Phenytoin Contraindicated
- Bictegravir + Phenytoin Contraindicated
- Cabotegravir + Phenytoin Contraindicated
- Doravirine + Phenytoin Contraindicated
- Elbasvir / grazoprevir + Phenytoin Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Phenytoin Contraindicated
Frequently asked questions
Can I take Methazolamide with Phenytoin?
MediHelp rates the interaction as minor. Methazolamide and Phenytoin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Both phenytoin and carbonic anhydrase inhibitors have been associated with disturbed bone and mineral metabolism. Concurrent long-term use may increase the risk of osteomalacia, mainly with acetazolamide.
How serious is the interaction between Methazolamide and Phenytoin?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: With long-term combined use, monitor calcium, vitamin D status and bone health, and supplement as needed.
What other medicines interact with Phenytoin?
MediHelp also lists interactions of Phenytoin with, for example, Artemether / lumefantrine, Bictegravir, Cabotegravir. The full list is on the Phenytoin page.
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