From the Guidelines
Tamiflu (oseltamivir) is generally considered safe for use during pregnancy when clinically indicated, as the benefits typically outweigh potential risks. Pregnant women who have influenza or high-risk exposure should take Tamiflu, as it can reduce the duration and severity of flu symptoms if started within 48 hours of symptom onset. The standard adult dosage is 75 mg twice daily for 5 days for treatment, or 75 mg once daily for 10 days for prevention after exposure, as recommended by the CDC 1.
Key Considerations
- Pregnant women are at higher risk for severe complications from influenza, including hospitalization and death, particularly during the second and third trimesters.
- Tamiflu works by inhibiting viral neuraminidase, preventing the release of new virus particles from infected cells.
- While no medication is completely without risk during pregnancy, observational studies have not shown increased risks of birth defects or adverse pregnancy outcomes with Tamiflu use, as noted in a study published in 2011 1.
- Pregnant women should also consider getting the influenza vaccine, which is recommended during any trimester, as a primary prevention strategy against the flu.
Important Details
- Oseltamivir is administered orally or by feeding tube without regard to meals, although administration with meals may improve gastrointestinal tolerability.
- The CDC recommends routine chemoprophylaxis with oseltamivir or zanamivir for 7 days after last known exposure, with a minimum of 14 days and continuing for 7 days after last known exposure if part of an institutional outbreak 1.
- Oseltamivir dosing for preterm infants is lower than for term infants, and preterm infants may have lower clearance of oseltamivir due to immature renal function 1.
From the FDA Drug Label
There are no adequate and well-controlled studies with oseltamivir phosphate for oral suspension in pregnant women to inform a drug-associated risk of adverse developmental outcomes. Available published epidemiological data suggest that oseltamivir phosphate for oral suspension, taken in any trimester, is not associated with an increased risk of birth defects However, these studies individually are limited by small sample sizes, use of different comparison groups, and some lacked information on dose, which preclude a definitive assessment of the risk
- Pregnancy Safety: The FDA drug label does not provide conclusive evidence to fully assess the safety of oseltamivir (Tamiflu) during pregnancy due to limitations in the available studies, including small sample sizes and lack of information on dose.
- Key Findings:
- No increased risk of birth defects was found in available epidemiological data.
- Animal reproduction studies showed no adverse developmental effects at clinically relevant exposures.
- Clinical Consideration: Pregnant women are at higher risk of severe complications from influenza, which may lead to adverse pregnancy and/or fetal outcomes.
- Recommendation: Although the data suggests no increased risk of birth defects, the limitations of the studies mean that a definitive assessment of the risk cannot be made 2.
From the Research
Safety of Oseltamivir During Pregnancy
- The safety of oseltamivir (Tamiflu) during pregnancy has been evaluated in several studies 3, 4, 5, 6, 7.
- According to these studies, oseltamivir is recommended for the treatment and prophylaxis of influenza in pregnant women, as it has been shown to prevent disease, shorten the duration of illness, and lessen the likelihood of complications 3, 4, 5, 6.
- The American College of Obstetricians and Gynecologists (ACOG) recommends that pregnant women with suspected or confirmed influenza receive antiviral treatment with oseltamivir or zanamivir, regardless of vaccination status or laboratory test results 4, 5.
- The Centers for Disease Control and Prevention (CDC) also advises that postexposure antiviral chemoprophylaxis can be considered for pregnant women who have had close contact with infectious individuals 4, 5.
- The physiologic adaptations of pregnancy may alter the pharmacokinetics and pharmacodynamics of oseltamivir, but the available data suggest that it is well-tolerated in pregnant women 3, 6.
- Influenza vaccination is also recommended for pregnant women, as it provides satisfactory immunity and reduces the risk of respiratory complications, and the available data show good tolerance of influenza vaccination performed during pregnancy 7.
Key Findings
- Oseltamivir is recommended for the treatment and prophylaxis of influenza in pregnant women 3, 4, 5, 6.
- ACOG and CDC recommend antiviral treatment with oseltamivir or zanamivir for pregnant women with suspected or confirmed influenza 4, 5.
- Oseltamivir is well-tolerated in pregnant women, but the physiologic adaptations of pregnancy may alter its pharmacokinetics and pharmacodynamics 3, 6.
- Influenza vaccination is recommended for pregnant women to provide satisfactory immunity and reduce the risk of respiratory complications 7.