Atypical antidepressant (NaSSA)
Mirtazapine 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 Mirtazapine (Mirtazapine). The combination is generally fine at 7.5mg, 15mg, 30mg, 45mg, but a small number of medications can reduce contraceptive efficacy meaningfully and need either a backup method or a switch.
How Mirtazapine 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 Mirtazapine acts on CYP3A4 determines whether Mirtazapine affects contraception. Most agents in Atypical antidepressant (NaSSA) have no clinically meaningful effect on the pill at 7.5mg, 15mg, 30mg, 45mg.
Practical guidance
According to the prescribing information for Mirtazapine, women on hormonal contraception should review Mirtazapine 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 Mirtazapine therapy is the standard mitigation.
Frequently asked questions
Will Mirtazapine make my pill less effective? ▾
Most Atypical antidepressant (NaSSA) medications at 7.5mg, 15mg, 30mg, 45mg do not affect oral contraceptive efficacy. The exceptions are CYP3A4-inducing drugs and a small number of others. The prescribing information for Mirtazapine states whether the interaction is meaningful.
Do I need a backup contraceptive on Mirtazapine? ▾
Backup contraception is needed only when there is a documented interaction between Mirtazapine and the contraceptive method. For most users at 7.5mg, 15mg, 30mg, 45mg, no backup is required. The pharmacist confirms whether Mirtazapine interacts with hormonal contraception.
Products containing Mirtazapine
More on Mirtazapine
- With alcoholMirtazapine and alcohol — is it safe to drink?
- With foodShould Mirtazapine be taken with food?
- Side effectsMirtazapine side effects: common, rare and warning signs
- Dosage guideMirtazapine dosage guide: how much to take and when
- OnsetHow fast does Mirtazapine start working?
- DurationHow long does Mirtazapine last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.