Second-generation H1 antihistamine
Loratadine 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 Loratadine (Loratadine). 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 Loratadine 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 Loratadine acts on CYP3A4 determines whether Loratadine 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 Loratadine, women on hormonal contraception should review Loratadine 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 Loratadine therapy is the standard mitigation.
Frequently asked questions
Will Loratadine 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 Loratadine states whether the interaction is meaningful.
Do I need a backup contraceptive on Loratadine? ▾
Backup contraception is needed only when there is a documented interaction between Loratadine and the contraceptive method. For most users at 5mg, 10mg, no backup is required. The pharmacist confirms whether Loratadine interacts with hormonal contraception.
Products containing Loratadine
More on Loratadine
- With alcoholLoratadine and alcohol — is it safe to drink?
- With foodShould Loratadine be taken with food?
- Side effectsLoratadine side effects: common, rare and warning signs
- Dosage guideLoratadine dosage guide: how much to take and when
- OnsetHow fast does Loratadine start working?
- DurationHow long does Loratadine last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.