I accidentally gave my 35 lb 3 year-old 1 tsp phenergan (promethazine) dm. the dose is suppose to be 1/2. she acts fine should i be worried?

No: Just giving double the dose once shd not matter. And esp if she is fine. Some doctors wld have used 5 ml especially at night at bedtime. So do not worry. Be careful with all medications in future.

Will be fine: The main side effect you will notice is increased sedation but should not cause any serious adverse effects.

Mgt: If she is otherwise well,it should be alright. If you do notice any changes,please contact your PCP Nasal saline rinses are effective in relieving congestion without the potential side effects.

Cough & cold : medications are not recommended for children < 6 years old. Promethazine in kids > 2 years can cause central nervous system, cardiovascular & respiratory depression, apnea, hallucinations, seizures & abnormal movements even in weight-based doses. DM can cause drowsiness, nausea, & asthma/allergy attacks because it releases histamine. Observation in a hospital-based pediatric ER would be safest.