Allergy and Antihistamines 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 Allergy and Antihistamines (Allergy and Antihistamines). The combination is generally fine at 30mg, 60mg, 120mg, 180mg, 5mg, but a small number of medications can reduce contraceptive efficacy meaningfully and need either a backup method or a switch.
How Allergy and Antihistamines 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, Fexofenadine, Loratadine acts on CYP3A4 determines whether Allergy and Antihistamines affects contraception. Most agents in Allergy and Antihistamines have no clinically meaningful effect on the pill at 30mg, 60mg, 120mg, 180mg, 5mg.
Practical guidance
According to the prescribing information for Cetirizine, Fexofenadine, Loratadine, women on hormonal contraception should review Allergy and Antihistamines 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 Allergy and Antihistamines therapy is the standard mitigation.
Frequently asked questions
Will Allergy and Antihistamines make my pill less effective? ▾
Most Allergy and Antihistamines medications at 30mg, 60mg, 120mg, 180mg, 5mg do not affect oral contraceptive efficacy. The exceptions are CYP3A4-inducing drugs and a small number of others. The prescribing information for Cetirizine, Fexofenadine, Loratadine states whether the interaction is meaningful.
Do I need a backup contraceptive on Allergy and Antihistamines? ▾
Backup contraception is needed only when there is a documented interaction between Allergy and Antihistamines and the contraceptive method. For most users at 30mg, 60mg, 120mg, 180mg, 5mg, no backup is required. The pharmacist confirms whether Cetirizine, Fexofenadine, Loratadine interacts with hormonal contraception.
Medications in Allergy and Antihistamines
More on Allergy and Antihistamines
- With alcoholAllergy and Antihistamines and alcohol — is it safe to drink?
- With foodShould Allergy and Antihistamines be taken with food?
- Side effectsAllergy and Antihistamines side effects: common, rare and warning signs
- For older adultsAllergy and Antihistamines after 60: doses and safety in older adults
- For womenAllergy and Antihistamines for women: indications and considerations
- For menAllergy and Antihistamines for men: indications and considerations
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.