Is Iohexol safe while breastfeeding?
Here is what LactMed, the Drugs and Lactation Database published by the U.S. National Institute of Child Health and Human Development (NICHD), reports about Iohexol. The text below is quoted from that source — it is not our own verdict.
Summary of use during breastfeeding
Limited information indicates that maternal doses of iohexol up to 45.3 grams (containing 21 grams of iodine) produce low levels in milk. In addition, because iohexol is poorly absorbed orally, it is not likely to reach the bloodstream of the infant or cause any adverse effects in breastfed infants. The manufacturer states that withholding breastfeeding for 10 hours after administration to minimize the exposure of the infant; however, guidelines developed by several professional organizations state that breastfeeding need not be disrupted after a nursing mother receives an iodine-containing contrast medium.[1-4]
Effects on the breastfed infant
A small for gestational age African-American infant was born at 36 weeks and 3 days. On the infant's fifth day of life, the mother underwent a contrast-enhanced imaging study using iohexol, after which the infant received breast milk from days 5 to 11. On day 11 of life, the neonate had an elevated thyroid-stimulating hormone and low free thyroxine levels, consistent with hypothyroidism. Urine iodine level in the infant was checked and found to be elevated. Because the thyroid alterations were thought to be transient, thyroid therapy was not given. The infant was ultimately found to have congenital thyroid dysgenesis with a genetic deletion in the gene RPS6KA3, consistent with Coffin–Lowry syndrome, and two other deletions.[6]
Effects on milk supply
Relevant published information was not found as of the revision date.
Levels in milk
Maternal Levels. Four mothers who were 1 week to 14 months postpartum received iohexol by rapid intravenous injection. Three received a dose of 50 mL (37.8 grams; 17.5 grams of iodine) and one received 60 mL (45.3 grams; 21 grams of iodine). Milk samples of 10 mL were collected 9 times over the 48 hours after the injection. The average iohexol milk concentration over the first 24 hours was 24.6 mg/L in the 3 women 1 week to 4 months postpartum and 130.5 mg/L in the one woman who was 14 months postpartum and weaning her infant. The authors calculated that the average amount of iohexol received by the first 3 infants over the first 24 hours would be 3.7 mg/kg or 0.5% of the weight-adjusted maternal dosage.[5]
Infant Levels. Relevant published information was not found as of the revision date.
Alternatives LactMed lists
Source: Drugs and Lactation Database (LactMed), National Institute of Child Health and Human Development (NICHD), via NCBI Bookshelf, record “Iohexol” (LM527). LactMed on NCBI Bookshelf. LactMed is a registered trademark of the U.S. Department of Health and Human Services.
Educational summary of an authoritative source — not medical advice. Never start, stop, or change a medicine while breastfeeding without confirming with your doctor.