Drug interactions
Drospirenone + Trimethoprim
Severity: Moderate
Drospirenone and Trimethoprim: 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
Drospirenone has antimineralocorticoid activity and can raise serum potassium, and trimethoprim independently blocks epithelial sodium channels in the distal nephron, reducing potassium excretion. Together they may cause clinically important hyperkalemia, particularly in patients with renal impairment, diabetes, or those taking ACE inhibitors or ARBs.
What this interaction means in plain words
Drospirenone and Trimethoprim 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.
Drospirenone belongs to Endocrine; Trimethoprim belongs to Anti Bacterial.
Why it happens
Additive potassium-retaining effects: drospirenone's aldosterone antagonism plus trimethoprim's amiloride-like ENaC blockade.
What to do
Check serum potassium and renal function before and during the first days of trimethoprim therapy in patients on drospirenone, especially if other potassium-raising drugs are used. Consider an alternative antibiotic or a different contraceptive in high-risk patients.
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 Drospirenone
Other interactions of Trimethoprim
Frequently asked questions
Can I take Drospirenone with Trimethoprim?
MediHelp rates the interaction as moderate. Drospirenone and Trimethoprim 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. Drospirenone has antimineralocorticoid activity and can raise serum potassium, and trimethoprim independently blocks epithelial sodium channels in the distal nephron, reducing potassium excretion. Together they may cause clinically important hyperkalemia, particularly in patients with renal impairment, diabetes, or those taking ACE inhibitors or ARBs.
How serious is the interaction between Drospirenone and Trimethoprim?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check serum potassium and renal function before and during the first days of trimethoprim therapy in patients on drospirenone, especially if other potassium-raising drugs are used. Consider an alternative antibiotic or a different contraceptive in high-risk patients.
What other medicines interact with Drospirenone?
MediHelp also lists interactions of Drospirenone with, for example, Belzutifan, Bosentan, Carbamazepine. The full list is on the Drospirenone page.
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