No reports describing the use of oxymetazoline during human lactation have been located. The molecular weight (about 260) is low enough to be excreted into breast milk, but topical decongestants have minimal systemic absorption (2).

Oxymetazoline is an α-adrenergic agent. It is indicated for temporary nasal congestion due to the common cold, hay fever, upper respiratory allergies, and sinusitis (1). Topical decongestants have minimal systemic absorption (2).

Animal Data: Studies for carcinogenicity have apparently not been conducted, nor have studies on fertility.

Placental Transfer: It is not known if oxymetazoline crosses the human placenta. The molecular weight (about 260) is low enough to cross, but the amount in the systemic circulation has apparently not been studied.

Human Data: The Collaborative Perinatal Project recorded only 2 cases of exposure from 50,282 mother-child pairs (3). Although there was no indication of risk for malformations, the number of women exposed is too small for any conclusion.

Uterine vessels are normally maximally dilated and have only α-adrenergic receptors (4). Use of the α-adrenergic agent, oxymetazoline, could cause constriction of these vessels and reduce uterine blood flow, thus producing fetal hypoxia and bradycardia. A 1985 case report illustrated this toxicity when a nonreactive nonstress test and a positive contraction stress test were discovered in a 20-year-old woman at 41 weeks (5). Persistent late fetal heart rate decelerations were observed, and blood obtained from the fetal scalp revealed a pH of 7.23. The mother had self-administered a nasal spray containing 0.05% oxymetazoline, two sprays in each nostril, 6 times in a 15.5-hour interval before the nonstress test with the last dose administered 0.5 hour before testing. The recommended dosage interval for the preparation was every 12 hours. Approximately 6 hours after the last dose, the late decelerations disappeared, and the normal beat-to-beat variability returned about 0.5 hour later. A normal male infant with Apgar scores of 9 and 9 at 1 and 5 minutes, respectively, was spontaneously delivered 14 hours after the last dose (5).

In contrast to the above case, a 1990 report described the results of a single dose (two full squirts) of 0.05% oxymetazoline (6). The drug was self-administered by 12 women with allergic rhinitis, sinusitis, or an upper respiratory tract infection. The otherwise healthy women were between 27 and 39 weeks. The effects of this dose on the maternal and fetal circulations were measured at 15-minute intervals for 2 hours after the dose. No significant changes were observed for maternal blood pressures or pulse rates, fetal aortic blood flow velocity, and fetal heart rate, or for the systolic to diastolic ratios in the uterine arcuate artery and umbilical artery. The investigators concluded that oxymetazoline, when administered at the recommended frequency, did not pose a risk for the healthy patient. Women with borderline placental reserve, however, should use the agent cautiously (6).