I wouldn't take the risk either. (The active in Phenergan is promethazine HCl in case you think I've got the wrong medication.)
QUOTE
FDA ALERT [4/2006] Medications containing promethazine hydrochloride (HCl) should not be used for children less than two years old because of possible breathing problems. This includes promethazine HCl in any form: syrups, suppositories, tablets, or injectables. Cases of breathing problems, some causing death, have been reported to the FDA when the drug was used in children less than two years old. Parents and caregivers should also be careful and get a doctor’s advice about giving promethazine HCl in any form to children age two and older. The labeling on all products, brand name and generic, has been changed to reflect these strengthened warnings. One manufacturer of suppositories and tablets has notified healthcare professionals of the changed label. The FDA is issuing this safety alert to make sure that healthcare professionals, other caregivers, and patients realize that the warnings apply to promethazine HCl syrups as well.
This is enough to put me off. It's not just a matter of one night as a child can have a reaction the first time you give it. There are more side effects further down
this website too.
Have you tried any of the gentler sleep methods ie Elizabeth Pantley's No cry sleep solution? They take longer (although it sounds as though you aren't having any luck with the things you are trying now) to work but don't stress the child as much.
Or like PP said, get your mum to come over and deal with your baby while you catch up on some sleep. This doesn't necessarily have to be at night either. A good nap in the middle of the day will help any sleep deprived person. Your mum might like to take him for a walk or something.