Ribavirin

The Basics

What is Ribavirin?

Used in therapy of chronic hepatitis C and other flavivirus infections.

Brand names for Ribavirin

Virazole

How Ribavirin is classified

Antiviral Agents

Ribavirin During Pregnancy

Ribavirin pregnancy category

Category XNote that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.

What we know about taking Ribavirin while pregnant

Ribavirin has demonstrated significant teratogenic and/or embryocidal potential in all animal species in which adequate studies have been conducted. Teratogenic effects were evident after single oral doses of 2.5 mg/kg or greater in the hamster, and after daily oral doses of 0.3 and 1.0 mg/kg in the rabbit and rat, respectively (estimated human equivalent doses of 0.12 and 0.14 mg/kg, based on body surface area adjustment for the adult). Malformations of the skull, palate, eye, jaw, limbs, skeleton, and gastrointestinal tract were noted. The incidence and severity of teratogenic effects increased with escalation of the drug dose. Survival of fetuses and offspring was reduced. Ribavirin caused embryo lethality in the rabbit at daily oral dose levels as low as 1 mg/kg. No teratogenic effects were evident in the rabbit and rat administered daily oral doses of 0.1 and 0.3 mg/kg, respectively with estimated human equivalent doses of 0.01 and 0.04 mg/kg, based on body surface area adjustment (see Pharmacokinetics). These doses are considered to define the No Observable Teratogenic Effects Level (NOTEL) for ribavirin in the rabbit and rat. Following oral administration of ribavirin in the pregnant rat (1.0 mg/kg) and rabbit (0.3 mg/kg), mean plasma levels of drug ranged from 0.104.20 µM[0.024-0.049 u/mL] at 1 hour after dosing, to undetectable levels at 24 hours. At 1 hour following the administration of 0.3 or 0.1 mg/kg in the rat and rabbit (NOTEL), respectively, mean plasma levels of drug in both species were near or below the limit of detection (0.05 µM; see Pharmacokinetics). Although clinical studies have not been performed, VIRAZOLE (ribavirin) may cause fetal harm in humans. As noted previously, ribavirin is concentrated in red blood cells and persists for the life of the cell. Thus the terminal half-life for the systemic elimination of ribavirin is essentially that of the half-life of circulating erythrocytes. The minimum interval following exposure to VIRAZOLE (ribavirin) before pregnancy may be safely initiated is unknown (see CONTRAINDICATIONS, WARNINGS, and Information for Health Care Personnel).

Taking Ribavirin While Breastfeeding

What are recommendations for lactation if you're taking Ribavirin?

Ribavirin has not been studied in nursing mothers being treated for hepatitis C infection. However, ribavirin is given directly to infants by inhalation to treat respiratory syncytial virus (RSV) infection. The amount in milk is likely to be lower than the doses received by infants treated with ribavirin for RSV infection. Hepatitis C is not transmitted through breastmilk[1][2] and breastmilk has been shown to inactivate hepatitis C virus (HCV).[3][4] However, the Centers for Disease Control recommends that mothers with HCV infection should consider abstaining from breastfeeding if their nipples are cracked or bleeding. It is not clear if this warning would apply to mothers who are being treated for hepatitis C. Infants born to mothers with HCV infection should be tested for HCV infection; because maternal antibody is present for the first 18 months of life and before the infant mounts an immunologic response, nucleic acid testing is recommended.[1][2]

Maternal / infant drug levels

Ribavirin has not been studied in nursing mothers being treated for hepatitis C infection. However, ribavirin is given directly to infants by inhalation to treat respiratory syncytial virus (RSV) infection. The amount in milk is likely to be lower than the doses received by infants treated with ribavirin for RSV infection. Hepatitis C is not transmitted through breastmilk[1][2] and breastmilk has been shown to inactivate hepatitis C virus (HCV).[3][4] However, the Centers for Disease Control recommends that mothers with HCV infection should consider abstaining from breastfeeding if their nipples are cracked or bleeding. It is not clear if this warning would apply to mothers who are being treated for hepatitis C. Infants born to mothers with HCV infection should be tested for HCV infection; because maternal antibody is present for the first 18 months of life and before the infant mounts an immunologic response, nucleic acid testing is recommended.[1][2]

Possible effects of Ribavirin on milk supply

Relevant published information was not found as of the revision date.

Possible alternatives to Ribavirin

(Hepatitis C) Interferon Alfa, Interferon Alfacon-1.