Summary of Use during Lactation

No published information is available on the use of orphenadrine during breastfeeding. Manufacturer’s estimates indicate that the amount in milk may be low. The drug’s anticholinergic activity might interfere with milk production. An alternate agent may be preferred.

Drug Levels

Maternal Levels. A European manufacturer of orphenadrine estimated that with a maternal dose of 150 mg, milk orphenadrine concentration would be about 300 to 400 mcg/L.[1] This implies that the relative infant dosage might be about 1.8 to 2.4% of the mother’s weight-adjusted dosage.

Infant Levels. Relevant published information was not found as of the revision date.

Effects in Breastfed Infants

Relevant published information was not found as of the revision date.

Effects on Lactation and Breastmilk

Orphenadrine has anticholinergic activity. Anticholinergics can inhibit lactation in animals, apparently by inhibiting growth hormone and oxytocin secretion.[2-6] Anticholinergic drugs can also reduce serum prolactin in nonnursing women.[7] The prolactin level in a mother with established lactation may not affect her ability to breastfeed.

References

1.

Chaplin S, Sanders GL, Smith JM. Drug excretion in human breast milk. Adv Drug React Ac Pois Rev. 1982;1:255–87.

2.

Aaron DK, Ely DG, Deweese WP, et al. Reducing milk production in ewes at weaning using restricted feeding and methscopolamine bromide. J Anim Sci. 1997;75:1434–42. [PubMed: 9250502]

3.

Powell MR, Keisler DH. A potential strategy for decreasing milk production in the ewe at weaning using a growth hormone release blocker. J Anim Sci. 1995;73:1901–5. [PubMed: 7592071]

4.

Daniel JA, Thomas MG, Powell MR, et al. Methscopolamine bromide blocks hypothalmic-stimulated release of growth hormone in ewes. J Anim Sci. 1997;75:1359–62. [PubMed: 9159285]

5.

Bizzarro A, Iannucci F, Tolino A, et al. Inhibiting effect of atropine on prolactin blood levels after stimulation with TRH. Clin Exp Obstet Gynecol. 1980;7:108–11. [PubMed: 6788407]

6.

Svennersten K, Nelson L, Juvnas-Moberg K. Atropinization decreases oxytocin secretion in dairy cows. Acta Physiol Scand. 1992;145:193–4. [PubMed: 1636447]

7.

Masala A, Alagna S, Devilla L, et al. Muscarinic receptor blockade by pirenzepine: Effect on prolactin secretion in man. J Endocrinol Invest. 1982;5:53–5. [PubMed: 6808052]

Substance Name

Orphenadrine

CAS Registry Number

83-98-7

Drug Class

Breast Feeding

Lactation

Antiparkinson Agents

Cholinergic Antagonists

Muscle Relaxants, Central

Parasympatholytics

Muscarinic Antagonists