The Centers for Disease Control and Prevention (CDC) recommends women in any trimester of their pregnancy who have a suspected or confirmed influenza infection receive prompt antiviral therapy with Tamiflu (oseltamavir) or Relenza (zanamivir).
Are Tamiflu and Relenza safe to use in pregnancy?
Relenza and Tamiflu are both FDA approved for treatment of influenza. Both drugs have been carefully looked at to understand their safety profile in pregnancy and we are continuing to monitor them closely. For a pregnant woman and her developing baby, the benefit of any drug needs to be considered in light of the risks from the drug and the risks from not treating the disease or condition.
The CDC has looked at these issues carefully for pregnant women: because the risks of influenza for pregnant women are serious, CDC believes that the benefits of antiviral therapy outweigh the potential for risks from the drugs.
Both drugs are designated "Pregnancy Category C," which means that they have not been studied in pregnant women. However, Pregnancy Category C does NOT mean the drug cannot be used in pregnant women. Pregnant women can and should receive a category C drug when the possible benefits of using the drug are more likely than the possible risk of harm to the woman or her baby.
What else should pregnant women know?
If your doctor diagnoses influenza and prescribes Tamiflu or Relenza for you, do not wait to start the treatment. Antiviral drugs are most beneficial if treatment starts within 2 days of the start of influenza symptoms. You will probably need to take the medicine for at least 5 days.
Don’t avoid getting a flu shot. Antiviral therapy does not substitute for vaccination against seasonal and or H1N1 influenza.