The Basics
What is Primidone?
Used alone or with other medications to control seizures.
Brand names for Primidone
Mysoline
How Primidone is classified
Anticonvulsants, Barbiturates
Primidone During Pregnancy
Primidone pregnancy category
Category N/ANote that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.
What we know about taking Primidone while pregnant
N/A
Taking Primidone While Breastfeeding
What are recommendations for lactation if you're taking Primidone?
Ample evidence exists that primidone taken during nursing can affect the breastfed infant. Infant serum levels of primidone and its metabolites are often near or in the therapeutic range and symptoms of sedation and poor nursing have been reported. On the other hand, infants exposed in utero sometimes have withdrawal symptoms that are either alleviated by breastfeeding or worsened when breastfeeding is abruptly stopped. If primidone is required by the mother, it is not a reason to discontinue breastfeeding. However the infant must be monitored for drowsiness, adequate nursing and weight gain, and developmental milestones, especially in younger, exclusively breastfed infants and when using combinations of anticonvulsant drugs. Measurement of an infant serum level might help rule out toxicity if there is a concern.
Maternal / infant drug levels
Ample evidence exists that primidone taken during nursing can affect the breastfed infant. Infant serum levels of primidone and its metabolites are often near or in the therapeutic range and symptoms of sedation and poor nursing have been reported. On the other hand, infants exposed in utero sometimes have withdrawal symptoms that are either alleviated by breastfeeding or worsened when breastfeeding is abruptly stopped. If primidone is required by the mother, it is not a reason to discontinue breastfeeding. However the infant must be monitored for drowsiness, adequate nursing and weight gain, and developmental milestones, especially in younger, exclusively breastfed infants and when using combinations of anticonvulsant drugs. Measurement of an infant serum level might help rule out toxicity if there is a concern.
Possible effects of Primidone on milk supply
No direct effect is known, but mothers taking antiepileptic drugs stop breastfeeding earlier and supplement more than mothers not taking antiepileptic drugs. Most of these reports occurred in older studies in which sedating agents such as phenobarbital and primidone were used. Infant sucking difficulties and sedation were reasons given for the reduced nursing.[9][13]
Possible alternatives to Primidone
None listed
List of References
Lactation sources: Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2006-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK501922/1. Espir MLE, Benton P, Will E et al. Sodium valproate (Epilim) – some clinical and pharmacological aspects. In: Legg NJ, ed. Clinical and pharmacological aspects of sodium valproate in the treatment of epilepsy: proceedings of a symposium. 1976;145-51.
2. Kaneko S, Sato T, Suzuki K. The levels of anticonvulsants in breast milk. Br J Clin Pharmacol. 1979;7:624-7. Letter. PMID: 465285
3. Niebyl JR, Blake DA, Freeman JM et al. Carbamazepine levels in pregnancy and lactation. Obstet Gynecol. 1979;53:139-40. PMID: 760015
4. Nau H, Rating D, Hauser I et al. Placental transfer and pharmacokinetics of primidone and its metabolites phenobarbital, PEMA, and hydroxyphenobarbital in neonates and infants of epileptic mothers. Eur J Clin Pharmacol. 1980;18:31-42. PMID: 7398746
5. Granstrom ML, Bardy AH, Hiilesmaa VK. Prolonged feeding difficulties of infants of primidone mothers during neonatal period: preliminary results from the Helsinki study. In: Janz D et al., eds. Epilepsy, pregnancy and the child. New York: Raven Press, 1982:357-8.
6. Kuhnz W, Koch S, Helge H et al. Primidone and phenobarbital during lactation period in epileptic women: total and free drug serum levels in the nursed infants and their effects on neonatal behavior. Dev Pharmacol Ther. 1988;11:147-54. PMID: 3383727
7. Meyer FP, Quednow B, Potrafki A et al. [The perinatal pharmacokinetics of anticonvulsant drugs]. Zentralbl Gynakol. 1988;110:1195-205. PMID: 3239295
8. Juul S. [Barbiturate poisoning via breast milk?]. Ugeskr Laeger. 1969;131:2257-8. PMID: 5372729
9. Kaneko S, Suzuki K, Sato T et al. The problems of antiepileptic medication in the neonatal period: is breast-feeding advisable? In: Janz D, Dam M, Richens A et al. Epilepsy, pregnancy and the child. New York: Raven Press, 1982:343-8.
10. Kuhnz W, Koch S, Jacob S et al. Ethosuximide in epileptic women during pregnancy and lactation period. Placental transfer, serum concentration in nursed infants. Br J Clin Pharmacol. 1984;18:671-7. PMID: 6508976
11. Knott C, Reynolds F, Clayden G. Infantile spasms on weaning from breast milk containing anticonvulsants. Lancet. 1987;330:272-3. Letter. PMID: 2886736
12. Rauchenzauner M, Kiechl-Kohlendorfer U, Rostasy K, Luef G. Old and new antiepileptic drugs during pregnancy and lactation – report of a case. Epilepsy Behav. 2011. PMID: 21444249
13. Hartmann AM, Koch S, Jager-Roman E, Helge H. [Breast feeding, weight gain and behaviour in newborns of epileptic women]. Monatsschr Kinderheilkd. 1994;142:505-12.
Disclaimer: This material is provided for educational purposes only and is not intended for medical advice, diagnosis, or treatment. Consult your healthcare provider with any questions.
