Thiazide diuretic
Hydrochlorothiazide 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 Hydrochlorothiazide (Hydrochlorothiazide). The combination is generally fine at 12.5mg, 25mg, 50mg, but a small number of medications can reduce contraceptive efficacy meaningfully and need either a backup method or a switch.
How Hydrochlorothiazide 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 Hydrochlorothiazide acts on CYP3A4 determines whether Hydrochlorothiazide affects contraception. Most agents in Thiazide diuretic have no clinically meaningful effect on the pill at 12.5mg, 25mg, 50mg.
Practical guidance
According to the prescribing information for Hydrochlorothiazide, women on hormonal contraception should review Hydrochlorothiazide 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 Hydrochlorothiazide therapy is the standard mitigation.
Frequently asked questions
Will Hydrochlorothiazide make my pill less effective? ▾
Most Thiazide diuretic medications at 12.5mg, 25mg, 50mg do not affect oral contraceptive efficacy. The exceptions are CYP3A4-inducing drugs and a small number of others. The prescribing information for Hydrochlorothiazide states whether the interaction is meaningful.
Do I need a backup contraceptive on Hydrochlorothiazide? ▾
Backup contraception is needed only when there is a documented interaction between Hydrochlorothiazide and the contraceptive method. For most users at 12.5mg, 25mg, 50mg, no backup is required. The pharmacist confirms whether Hydrochlorothiazide interacts with hormonal contraception.
Products containing Hydrochlorothiazide
More on Hydrochlorothiazide
- With alcoholHydrochlorothiazide and alcohol — is it safe to drink?
- With foodShould Hydrochlorothiazide be taken with food?
- Side effectsHydrochlorothiazide side effects: common, rare and warning signs
- Dosage guideHydrochlorothiazide dosage guide: how much to take and when
- OnsetHow fast does Hydrochlorothiazide start working?
- DurationHow long does Hydrochlorothiazide last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.