Tricyclic antidepressant (TCA)
Amitriptyline 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 Amitriptyline (Amitriptyline). The combination is generally fine at 10mg, 25mg, 50mg, 75mg, 100mg, but a small number of medications can reduce contraceptive efficacy meaningfully and need either a backup method or a switch.
How Amitriptyline 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 Amitriptyline acts on CYP3A4 determines whether Amitriptyline affects contraception. Most agents in Tricyclic antidepressant (TCA) have no clinically meaningful effect on the pill at 10mg, 25mg, 50mg, 75mg, 100mg.
Practical guidance
According to the prescribing information for Amitriptyline, women on hormonal contraception should review Amitriptyline 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 Amitriptyline therapy is the standard mitigation.
Frequently asked questions
Will Amitriptyline make my pill less effective? ▾
Most Tricyclic antidepressant (TCA) medications at 10mg, 25mg, 50mg, 75mg, 100mg do not affect oral contraceptive efficacy. The exceptions are CYP3A4-inducing drugs and a small number of others. The prescribing information for Amitriptyline states whether the interaction is meaningful.
Do I need a backup contraceptive on Amitriptyline? ▾
Backup contraception is needed only when there is a documented interaction between Amitriptyline and the contraceptive method. For most users at 10mg, 25mg, 50mg, 75mg, 100mg, no backup is required. The pharmacist confirms whether Amitriptyline interacts with hormonal contraception.
Products containing Amitriptyline
More on Amitriptyline
- With alcoholAmitriptyline and alcohol — is it safe to drink?
- With foodShould Amitriptyline be taken with food?
- Side effectsAmitriptyline side effects: common, rare and warning signs
- Dosage guideAmitriptyline dosage guide: how much to take and when
- OnsetHow fast does Amitriptyline start working?
- DurationHow long does Amitriptyline last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.