Summary of Use during Lactation

Limited information indicates that maternal doses of trihexyphenidyl up to 4 mg daily together with haloperidol did not produce any adverse effects in breastfed infants. Long-term use of trihexyphenidyl might reduce milk production or milk letdown, but a single dose is not likely to interfere with breastfeeding. During long-term use, observe for signs of decreased lactation (e.g., insatiety, poor weight gain).

Drug Levels

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

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

Effects in Breastfed Infants

One woman with schizophrenia took trihexyphenidyl and haloperidol during 3 pregnancies and postpartum. The trihexyphenidyl dose was 4 mg daily in all 3 pregnancies. She breastfed (extent not stated) all 3 children for 6 to 8 months using the same doses. Development was age-appropriate in all children aged 16 months at 8 years of age at the time of assessment.[1]

Effects on Lactation and Breastmilk

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.

One woman with schizophrenia took trihexyphenidyl and haloperidol during 3 pregnancies and postpartum. She was able to breastfeed (extent not stated) all 3 children for 6 to 8 months.[1] The prolactin elevating effect of haloperidol might have counteracted any prolactin lowering effect of trihexyphenidyl.

References

1.

Mendhekar DN, Andrade C. Uneventful use of haloperidol and trihehexyphenidyl during three consecutive pregnancies. Arch Womens Ment Health. 2011;14:83–4. [PubMed: 21116668]

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, Juvnäs-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

Trihexyphenidyl

CAS Registry Number

144-11-6

Drug Class

Breast Feeding

Lactation

Antiparkinson Agents

Muscarinic Antagonists

Parasympatholytics