Is Levsin safe during pregnancy?

What does the evidence say about Levsin during pregnancy?

1. The Levsin label states that animal reproduction studies have not been conducted, that it is not known whether the drug can cause fetal harm, and that it should be given to a pregnant woman only if clearly needed. 1
2. Hyoscyamine is excreted in human milk, and the label advises caution when it is given to a nursing parent. 1
3. Hyoscyamine and dicyclomine ease abdominal pain and cramping by relaxing smooth muscle, but a Cochrane analysis of antispasmodics was graded low-quality because of high risk of bias, and the American College of Gastroenterology does not recommend the class. 2
4. Dicyclomine, the other common antispasmodic, at least has older epidemiologic data at doses up to 40 mg a day showing no rise in birth defects, which is more than exists for hyoscyamine. 3
5. For mild gastrointestinal symptoms in pregnancy, gastroenterology guidance starts with lifestyle and dietary changes before any drug enters the picture. 4

Is Levsin safe in each trimester?

• First trimester. There is no reassuring dataset to lean on here, only the absence of reported problems across decades of use. If you were taking hyoscyamine for gut spasm before pregnancy, this is a first-visit conversation, and dietary and behavioral approaches are usually explored before deciding whether to continue.
• Second trimester. Cramping often eases as the second trimester settles. Hyoscyamine dries secretions and slows the gut, which can trade one uncomfortable symptom for constipation and a dry mouth, so the honest question is whether it is still earning its place.
• Third trimester. Anticholinergic effects land harder now, when constipation, reflux and overheating are already common. Hyoscyamine also passes into breast milk, so the label advises caution while nursing, which makes a postpartum plan worth setting before delivery.