Potassium-sparing diuretic / aldosterone antagonist
Spironolactone with the birth control pill
Many women of reproductive age take a combined or progestogen-only oral contraceptive while also using a chronic medication such as Spironolactone (Spironolactone). The combination is generally fine at 25mg, 50mg, 100mg, but a small number of medications can reduce contraceptive efficacy meaningfully and need either a backup method or a switch.
How Spironolactone can affect contraceptive efficacy
Combined and progestogen-only contraceptives are metabolised through CYP3A4. Strong CYP3A4 inducers (some antiepileptics, rifampicin, St John's Wort) lower contraceptive plasma levels and reduce efficacy. Whether Spironolactone acts on CYP3A4 determines whether Spironolactone affects contraception. Most agents in Potassium-sparing diuretic / aldosterone antagonist have no clinically meaningful effect on the pill at 25mg, 50mg, 100mg.
Practical guidance
According to the prescribing information for Spironolactone, women on hormonal contraception should review Spironolactone with the prescribing pharmacist or doctor. Where an interaction is documented, additional barrier contraception or switching to a non-oral method (IUD, implant) for the duration of Spironolactone therapy is the standard mitigation.
Frequently asked questions
Will Spironolactone make my pill less effective? ▾
Most Potassium-sparing diuretic / aldosterone antagonist medications at 25mg, 50mg, 100mg do not affect oral contraceptive efficacy. The exceptions are CYP3A4-inducing drugs and a small number of others. The prescribing information for Spironolactone states whether the interaction is meaningful.
Do I need a backup contraceptive on Spironolactone? ▾
Backup contraception is needed only when there is a documented interaction between Spironolactone and the contraceptive method. For most users at 25mg, 50mg, 100mg, no backup is required. The pharmacist confirms whether Spironolactone interacts with hormonal contraception.
Products containing Spironolactone
More on Spironolactone
- With alcoholSpironolactone and alcohol — is it safe to drink?
- With foodShould Spironolactone be taken with food?
- Side effectsSpironolactone side effects: common, rare and warning signs
- Dosage guideSpironolactone dosage guide: how much to take and when
- OnsetHow fast does Spironolactone start working?
- DurationHow long does Spironolactone last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.