Birth Control Pills Should Be Temporarily Discontinued When Taking Paxlovid
Women should use an alternative or additional form of contraception during treatment with Paxlovid (nirmatrelvir/ritonavir) and not rely on hormonal contraceptives alone. This recommendation is clearly stated in the FDA drug label for Paxlovid 1.
Why Birth Control Pills Are Affected by Paxlovid
Paxlovid contains ritonavir, which is a potent inhibitor of CYP3A enzymes. This creates important drug interactions with many medications, including hormonal contraceptives:
- The FDA label explicitly states: "Tell your healthcare provider if you are taking combined birth control (hormonal contraceptive). PAXLOVID may affect how your hormonal contraceptives work." 1
- The label further advises: "Females who are able to become pregnant should use another effective alternative form of contraception or an additional barrier method of contraception during treatment with PAXLOVID." 1
Mechanism of Interaction
The interaction occurs primarily due to the ritonavir component in Paxlovid:
- Ritonavir can accelerate the clearance of certain drugs, including oral contraceptives 2
- This is consistent with what we know about ritonavir-boosted protease inhibitors, which may reduce contraceptive efficacy by decreasing contraceptive hormone levels 2
Duration of Precaution
The precaution applies specifically during the treatment course with Paxlovid:
- Paxlovid is typically prescribed for a 5-day course 1
- Alternative contraception should be used during this period and potentially for a short time afterward
Recommended Alternative Contraceptive Options
During the 5-day Paxlovid treatment period, consider these alternatives:
- Barrier methods (condoms) used consistently 3
- Intrauterine devices (IUDs), which are not affected by drug interactions 3
- Depot medroxyprogesterone acetate (DMPA) injections, which are generally not affected by drug interactions 3
Important Clinical Considerations
- Do not stop Paxlovid treatment due to this interaction - the benefits of treating COVID-19 outweigh the temporary need for alternative contraception
- This interaction is similar to that seen with other ritonavir-containing regimens 4
- Failure to address this interaction could potentially result in unintended pregnancy
- The short 5-day course of Paxlovid minimizes the duration of risk
Monitoring and Follow-up
- Monitor for breakthrough bleeding, which could indicate reduced contraceptive effectiveness
- Resume normal contraceptive use after completing the full course of Paxlovid
- If pregnancy is a significant concern, consider emergency contraception if unprotected intercourse occurs during this period
This recommendation prioritizes patient safety by preventing potential contraceptive failure while ensuring effective COVID-19 treatment with Paxlovid.