- feeling sleepy during the daytime – this usually wears off 12 hours after a dose. Do not drive, cycle or use tools or machinery if you’re feeling this way.
- nightmares – speak to your pharmacist or doctor if these do not go away or are troubling you.
- feeling dizzy or unsteady on your feet, or having difficulty concentrating – stop what you’re doing and sit or lie down until you feel better. If the feeling does not go away or is troubling you, do not take any more medicine and speak to a pharmacist or doctor.
- headaches – make sure you rest and drink plenty of fluids. Talk to your doctor if the headaches last longer than a week or are severe.
7. Pregnancy and breastfeeding
Promethazine and pregnancy
Promethazine can be used in pregnancy. There is no good evidence that it is harmful to your baby, but it can have side effects such as drowsiness.
For the treatment of hay fever your doctor or pharmacist may recommend a non-drowsy antihistamine (loratadine).
Promethazine and breastfeeding
If your doctor or health visitor says your baby is healthy, promethazine can be used during breastfeeding. If you are prescribed promethazine, it’s better to take occasional doses or only for a short time.
It’s not known how much promethazine passes into breast milk but it is likely to be a small amount. It has been used for many years without causing babies to have side effects. However, promethazine is a drowsy antihistamine, so may also make your baby sleepy too. It may also reduce the amount of milk you produce.
If you’re breastfeeding or planning to breastfeed, talk to your doctor or pharmacist, as other medicines might be better while you’re breastfeeding.
If your baby is not feeding as well as usual, seems unusually sleepy, or seems irritable, or if you have any other concerns about your baby, talk to your doctor, pharmacist, health visitor or midwife.