From the FDA Drug Label
8 USE IN SPECIFIC POPULATIONS
- 1 Pregnancy Teratogenic Effects, Pregnancy Category B. Administration of tamsulosin hydrochloride to pregnant female rats at dose levels up to approximately 50 times the human therapeutic AUC exposure (300 mg/kg/day) revealed no evidence of harm to the fetus. Administration of tamsulosin hydrochloride to pregnant rabbits at dose levels up to 50 mg/kg/day produced no evidence of fetal harm. Tamsulosin Hydrochloride Capsules are not indicated for use in women.
The use of tamsulosin in pregnancy is categorized as Pregnancy Category B.
- Key points:
- No evidence of harm to the fetus was found in studies with pregnant female rats and rabbits.
- Tamsulosin Hydrochloride Capsules are not indicated for use in women. Given the information, tamsulosin should be used with caution in pregnant women, as it is not indicated for use in women, but animal studies did not show evidence of fetal harm 1.
From the Research
Tamsulosin can be considered safe for use during pregnancy, particularly in the second and third trimesters, for the treatment of symptomatic urolithiasis, as it does not appear to be associated with adverse maternal or fetal outcomes, according to the most recent and highest quality study available 2.
Key Points to Consider
- The use of tamsulosin in pregnancy is supported by a study published in 2020, which found no significant differences in maternal or infant outcomes between women who received tamsulosin as medical expulsive therapy and those who did not 2.
- The study evaluated the safety and efficacy of tamsulosin in 207 pregnant patients presenting with renal colic, and found that short-term use of tamsulosin in the second and third trimesters was not associated with adverse maternal or infant outcomes 2.
- Another study published in 2016 also found that tamsulosin medical expulsive therapy was not associated with adverse maternal or fetal outcomes, and may be considered as adjunctive therapy for urolithiasis during pregnancy 3.
- It is essential to weigh the potential benefits and risks of using tamsulosin during pregnancy, and to consider alternative treatments that have better established safety profiles during pregnancy.
- Any woman who is pregnant or planning pregnancy and has been prescribed tamsulosin should consult with her healthcare provider to discuss the most appropriate treatment options.
Important Considerations
- Tamsulosin is classified as a category B medication by the FDA, meaning that animal studies have not shown risk, but adequate human studies are lacking 3.
- The medication works by relaxing smooth muscles in the bladder neck and prostate, improving urinary flow.
- The most common adverse events associated with tamsulosin are dizziness, abnormal ejaculation, and rhinitis, but these are not typically a concern during pregnancy 4, 5.
- The pharmacokinetics of tamsulosin are not significantly affected by age, renal impairment, or mild to moderate hepatic impairment, but concomitant exposure to potent CYP3A4 inhibitors can increase the exposure of tamsulosin 6.