Second-generation H1 antihistamine
Cetirizine 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 Cetirizine (Cetirizine). The combination is generally fine at 5mg, 10mg, but a small number of medications can reduce contraceptive efficacy meaningfully and need either a backup method or a switch.
How Cetirizine 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 Cetirizine acts on CYP3A4 determines whether Cetirizine affects contraception. Most agents in Second-generation H1 antihistamine have no clinically meaningful effect on the pill at 5mg, 10mg.
Practical guidance
According to the prescribing information for Cetirizine, women on hormonal contraception should review Cetirizine 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 Cetirizine therapy is the standard mitigation.
Frequently asked questions
Will Cetirizine make my pill less effective? ▾
Most Second-generation H1 antihistamine medications at 5mg, 10mg do not affect oral contraceptive efficacy. The exceptions are CYP3A4-inducing drugs and a small number of others. The prescribing information for Cetirizine states whether the interaction is meaningful.
Do I need a backup contraceptive on Cetirizine? ▾
Backup contraception is needed only when there is a documented interaction between Cetirizine and the contraceptive method. For most users at 5mg, 10mg, no backup is required. The pharmacist confirms whether Cetirizine interacts with hormonal contraception.
Products containing Cetirizine
More on Cetirizine
- With alcoholCetirizine and alcohol — is it safe to drink?
- With foodShould Cetirizine be taken with food?
- Side effectsCetirizine side effects: common, rare and warning signs
- Dosage guideCetirizine dosage guide: how much to take and when
- OnsetHow fast does Cetirizine start working?
- DurationHow long does Cetirizine last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.