Question

I am a breastfeeding mother and i want to know if it is safe to use Phenytoin? Is Phenytoin safe for nursing mother and child? Does Phenytoin extracts into breast milk? Does Phenytoin has any long term or short term side effects on infants? Can Phenytoin influence milk supply or can Phenytoin decrease milk supply in lactating mothers?

Phenytoin lactation summary

Phenytoin is safe in breastfeeding
  • DrLact safety Score for Phenytoin is 1 out of 8 which is considered Safe as per our analyses.
  • A safety Score of 1 indicates that usage of Phenytoin is mostly safe during lactation for breastfed baby.
  • Our study of different scientific research also indicates that Phenytoin does not cause any serious side effects in breastfeeding mothers.
  • Most of scientific studies and research papers declaring usage of Phenytoin safe in breastfeeding are based on normal dosage and may not hold true for higher dosage.
  • Score calculated using the DrLact safety Version 1.2 model, this score ranges from 0 to 8 and measures overall safety of drug in lactation. Scores are primarily calculated using publicly available case studies, research papers, other scientific journals and publically available data.

Answer by Dr. Ru: About Phenytoin usage in lactation

Type IB antiarrhythmic agent and anticonvulsant drug. It is excreted into breast milk in clinically non-significant amount and no problems have appeared on clinical follow up, and, long-term psychomotor development in infants whose mothers received this treatment, except in some isolated cases of patients who were on anticonvulsant polytherapy.Plasma levels in these infants were undetectable or very low. It may appear a withdrawal syndrome with hyperexcitability after abruptly stopping breastfeeding. It has been authorized for use in infants and newborns. American Academy of Pediatrics states that it is usually compatible with breastfeeding medication.WHO List of Essential Medicines 2002: compatible with breastfeeding.

Answer by DrLact: About Phenytoin usage in lactation

Breastfeeding during phenytoin monotherapy does not appear to adversely affect infant growth or development, and breastfed infants had higher IQs and enhanced verbal abilities than nonbreastfed infants at 6 years of age in one study.[1] If phenytoin is required by the mother, it is not necessarily a reason to discontinue breastfeeding. Because of the low levels of phenytoin in breastmilk, amounts ingested by the infant are small and usually cause no difficulties in breastfed infants when used alone except for rare idiosyncratic reactions. Combination therapy with sedating anticonvulsants or psychotropics may result in infant sedation or withdrawal reactions. In one case report, maternal phenytoin dosage requirements decreased as breastfeeding was discontinued.[2]

Phenytoin Side Effects in Breastfeeding

A mother was taking phenobarbital 390 mg daily and phenytoin 400 mg daily during pregnancy and postpartum. Her infant was drowsy at birth, refused to suck and was given partial formula feeding. At 5 days of age, her infant was admitted to the hospital pale and collapsed with bruising, bleeding, and a decreased hemoglobin, thought to be due to methemoglobinemia. Breastfeeding was discontinued and the infant was given a transfusion which rapidly improved her condition. On day 10, the mother resumed breastfeeding the infant. Within 24 hours the infant was extremely sedated and refused to suck and was fed breastmilk with a spoon. The sedation persisted for 2 days until breastmilk was discontinued permanently because of a return of methemoglobinemia. The extreme sedation was probably due to phenobarbital in the milk and the methemoglobinemia was probably caused by the phenytoin.[14] One clinician reported that the breastfed infants of 28 mothers who were taking phenytoin 100 to 200 mg 3 times daily had no adverse reactions including drowsiness or lethargy.[15] No adverse effects were noted in the breastfed neonates of 2 mothers who were taking phenytoin 300 mg daily.[3] A 10-week-old breastfed infant whose mother was taking clemastine, phenytoin and carbamazepine was drowsy, refused to feed, was irritable, and had high-pitched crying.[16] These side effects were possibly caused by clemastine in breastmilk, but the other drugs could also have contributed. A probable case of drug-induced drowsiness occurred in a newborn whose mother was taking primidone, carbamazepine and phenytoin (dosages not stated). At day 30, breastfeeding was discontinued because of the drowsiness that occurred after each feeding and poor weight gain. The same group of researchers found that 15 partially breastfed infants whose mothers were taking various anticonvulsants, including phenytoin, gained weight at a slower rate during the first 5 days postpartum than did 75 infants of epileptic mothers who bottle fed or control mothers taking no medications.[17] Drowsiness, pallor and feeding difficulties in a 2-week-old were possibly caused by primidone and phenytoin in breastmilk. Possible drug-related drowsiness, pallor and feeding difficulties were reported in a 4-day-old whose mother was taking primidone, phenobarbital, phenytoin and sulthiame.[18] Although phenytoin might have contributed to these outcomes, it is more likely that they were due primarily to the more sedating anticonvulsants, primidone and phenobarbital. Two breastfed infants (one full, one partial) whose mothers took phenytoin during pregnancy and postpartum became hyperexcitable when their serum phenytoin dropped to unmeasurable levels at 3 to 6 weeks of age.[19] In a long-term study on infants exposed to anticonvulsants during breastfeeding, no difference in average intelligence quotient at 3 years of age was found between infants who were breastfed (n = 17) a median of 6 months and those not breastfed (n = 23) when their mothers were taking phenytoin.[20] At 6 years of age, extensive psychological and intelligence testing found no difference between the breastfed and nonbreastfed infants.[1]

Synonyms of Phenytoin

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