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Patisiran Pregnancy and Breastfeeding Warnings

Patisiran is also known as: Onpattro

Medically reviewed by Drugs.com. Last updated on Jul 14, 2020.

Patisiran Pregnancy Warnings

Administration of this drug or a rodent-specific pharmacologically active surrogate to female rats weekly (0, 0.15, 0.5, or 1.5 mg/kg) starting 2 weeks prior to mating and continuing throughout organogenesis resulted in no adverse effects on fertility or embryofetal development. Weekly administration to pregnant rabbits (0, 0.1, 0.3, or 0.6 mg/kg) during the period of organogenesis produced no effects on embryofetal development. However, in a separate study in pregnant rabbits, weekly administration at slightly higher doses (0, 0.3, 1 or 2 mg/kg) resulted in embryofetal mortality and reduced fetal body weight at the mid and high doses, doses which were also associated with maternal toxicity. In humans, due to the potential teratogenic risk arising from unbalanced vitamin A levels, this drug should not be used during pregnancy, unless the clinical condition of the woman requires treatment. As a precautionary measure, vitamin A and thyroid stimulating hormone levels should be obtained early in pregnancy along with close monitoring of fetus. There are no controlled data in human pregnancy.

US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D, and X are being phased out.

Benefit should outweigh risk

US FDA pregnancy category: Not assigned

Risk Summary: There is no available data on use in pregnant women to inform a drug-associated risk, however, unbalanced vitamin A levels (too high or too low) during the first 60 days of pregnancy may be associated with an increased risk of fetal malformations; developmental toxicity has been observed in animal studies at maternally toxic doses.

Comments:
-Pregnancy should be excluded before treatment initiation; women of childbearing potential should be encouraged to use effective contraception.
-For women who intend to become pregnant, some authorities recommend discontinuing this drug and vitamin A supplementation and ensuring vitamin A levels return to normal before conception is attempted.
-For patients who become pregnant while on therapy, some authorities recommend discontinuing therapy and vitamin A supplementation unless there are clinical signs of vitamin A deficiency; for patients requiring vitamin A supplementation, the vitamin A dose should not exceed 2500 IU per day.

See references

Patisiran Breastfeeding Warnings

Benefit should outweigh risk

Excreted into human milk: Unknown
Excreted into animal milk: No (lipid components: yes)

Comments:
-There are no data on the effects of this drug on the breastfed infant or its effects on milk production.
-The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for this drug and any potential adverse effects to the breastfed infant from the drug or from the underlying maternal condition.

This drug was not detected in the milk of lactating rats; however, small amounts of the lipid components DLin-MC3-DMA and PEG2000-C-DMG were present in milk (up to 7% of concomitant maternal plasma concentrations). There were no adverse effects on the pups.

See references

References for pregnancy information

  1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  2. "Product Information. Onpattro (patisiran)." Alnylam Phamraceuticals, Cambridge, MA.

References for breastfeeding information

  1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  2. "Product Information. Onpattro (patisiran)." Alnylam Phamraceuticals, Cambridge, MA.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.