Drug interactions
Methazolamide + Sulphasalazine
Severity: Moderate
Methazolamide and Sulphasalazine: 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
Sulfasalazine is a salicylate-containing sulfonamide and its salicylate-related moiety competes with carbonic anhydrase inhibitors for renal tubular secretion. This may raise levels of both drugs and increase the risk of adverse effects including CNS toxicity. The evidence is mostly extrapolated from aspirin with acetazolamide.
What this interaction means in plain words
Methazolamide and Sulphasalazine 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.
Why it happens
Competition for renal tubular secretion and possible shifting of salicylate into the CNS under carbonic anhydrase inhibition.
What to do
Monitor for drowsiness, confusion, tinnitus and metabolic acidosis, and reduce the dose of either drug if symptoms appear.
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 Sulphasalazine
- Deferiprone + Sulphasalazine Major
- Pexidartinib + Sulphasalazine Major
- Sepiapterin + Sulphasalazine Major
- Acalabrutinib + Sulphasalazine Moderate
- Aceclofenac + Sulphasalazine Moderate
- Asciminib + Sulphasalazine Moderate
Frequently asked questions
Can I take Methazolamide with Sulphasalazine?
MediHelp rates the interaction as moderate. Methazolamide and Sulphasalazine 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. Sulfasalazine is a salicylate-containing sulfonamide and its salicylate-related moiety competes with carbonic anhydrase inhibitors for renal tubular secretion. This may raise levels of both drugs and increase the risk of adverse effects including CNS toxicity. The evidence is mostly extrapolated from aspirin with acetazolamide.
How serious is the interaction between Methazolamide and Sulphasalazine?
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 for drowsiness, confusion, tinnitus and metabolic acidosis, and reduce the dose of either drug if symptoms appear.
What other medicines interact with Sulphasalazine?
MediHelp also lists interactions of Sulphasalazine with, for example, Deferiprone, Pexidartinib, Sepiapterin. The full list is on the Sulphasalazine page.
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