This NHS content is written for people in England. Medicine names, availability, prescribing and services may differ in other countries.
Diltiazem and pregnancy
You can use diltiazem during pregnancy, although it's not usually recommended.
If you're taking diltiazem to treat high blood pressure, you might be switched to a different medicine if you're pregnant.
If you're taking diltiazem for angina or heart rhythm problems, you should be reviewed by a pregnancy specialist (obstetrician) and a heart specialist (cardiologist). Keep taking diltiazem until you've had your review.
If you're using diltiazem to treat anal fissures, speak to your doctor who may suggest an alternative medicine.
Diltiazem and breastfeedingIf your doctor or health visitor says your baby is healthy, you can take diltiazem while breastfeeding.
There is not much information about using diltiazem while breastfeeding, but some information shows that it passes into breast milk in tiny amounts. It's unlikely to harm your baby. However, your doctor might suggest an alternative medicine that we know more about.
If you use the cream or ointment, make sure that you've washed your hands before picking up your baby.
If you do breastfeed while taking diltiazem and you notice that your baby is not feeding as well as usual, seems unusually sleepy, looks paler than usual, or if you have any other concerns about your baby, then talk to your health visitor midwife, pharmacist or doctor as soon as possible.
Diltiazem and fertilityDiltiazem may affect male fertility. There's no evidence that diltiazem affects fertility in women.
If you're trying for a baby, or having problems getting pregnant while taking diltiazem, then speak to your doctor.
Meds New IA (H2) - Pregnancy non-urgent care card
Tell your doctor if you're:
- trying to get pregnant
- pregnant
- breastfeeding
View the original NHS website page ↗. Refreshed 19 August 2026.
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