Norvasc 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 Norvasc (Amlodipine). The combination is generally fine at 2.5mg, 5mg, 10mg, but a small number of medications can reduce contraceptive efficacy meaningfully and need either a backup method or a switch.
How Norvasc 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 Amlodipine acts on CYP3A4 determines whether Norvasc affects contraception. Most agents in Cardiovascular Medications have no clinically meaningful effect on the pill at 2.5mg, 5mg, 10mg.
Practical guidance
According to the prescribing information for Amlodipine, women on hormonal contraception should review Norvasc 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 Norvasc therapy is the standard mitigation.
Frequently asked questions
Will Norvasc make my pill less effective? ▾
Most Cardiovascular Medications medications at 2.5mg, 5mg, 10mg do not affect oral contraceptive efficacy. The exceptions are CYP3A4-inducing drugs and a small number of others. The prescribing information for Amlodipine states whether the interaction is meaningful.
Do I need a backup contraceptive on Norvasc? ▾
Backup contraception is needed only when there is a documented interaction between Norvasc and the contraceptive method. For most users at 2.5mg, 5mg, 10mg, no backup is required. The pharmacist confirms whether Amlodipine interacts with hormonal contraception.
More on Norvasc
- With alcoholNorvasc and alcohol — is it safe to drink?
- With foodShould Norvasc be taken with food?
- Side effectsNorvasc side effects: common, rare and warning signs
- Dosage guideNorvasc dosage guide: how much to take and when
- OnsetHow fast does Norvasc start working?
- DurationHow long does Norvasc last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.