Histamine-1 receptors are also found in the brain and spinal cord.Antihistamines are very good at relieving symptoms of an allergic reaction, such as: First-generation antihistamines were developed more than seventy years ago and are still in widespread use today.Benzodiazepines (BZDs), antihistamines, and opioids are a few classes of sedating drugs commonly used by breastfeeding mothers.As a general rule, when the relative infant dose (the amount of a drug excreted into breast milk relative to the maternal dose) is less than 10%, it is considered compatible with breastfeeding.No gene polymorphisms were associated with infant sedation, but ABCB1 2677GT/A was associated with an increased risk of maternal sedation.Additionally, compared with mothers with asymptomatic infants, mothers with infants showing CNS depression used oxycodone for a significantly longer period ( Mothers were provided with a copy of the guidelines when prescribed codeine for postpartum pain.There were only 5 reports (2.1%) of neonate sedation, which is 8-fold lower than in our previous study (16.7%). Furthermore, infant sedation was not associated with maternal genetic polymorphisms in ABCB1, CYP 2D6, catechol-O-methyltransferase, uridine diphosphate-dependent glucuronosyltransferase 2B7, and µ opioid receptor.The authors concluded that the Motherisk guideline is effective in lowering the risk of neonatal CNS depression, even for those who are at high risk due to genetic polymorphisms.
They are also more likely than second-generation antihistamines to impair a person’s ability to drive or operate machinery.
Mothers using sedating drugs should monitor their breastfed infants for signs of CNS depression (eg, drowsiness; difficulty breathing, feeding, or latching; or cyanosis), paradoxical effects (eg, unusual excitement, irritability), or inadequate weight gain.
Thirty percent of Motherisk's consultations deal with the safety of drugs during breastfeeding.
Another Motherisk follow-up study involving 85 infants exposed to first- or second-generation antihistamines through breast milk reported 6 cases of irritability, 1 case of drowsiness, and 1 case of diarrhea.
A similar study involving 234 infants exposed to antihistamines through breast milk (54% were exposed to first-generation antihistamines and 46% were exposed to second-generation antihistamines) reported 53 cases (22.6%) of irritability, drowsiness, or decreased sleep in breastfed infants.
Antihistamines are a class of agents that block histamine release from histamine-1 receptors and are mostly used to treat allergies or cold and flu symptoms, although some first-generation antihistamines may also be used for other conditions.