It's unlikely that you'll get addicted to promethazine. But it's best that you only take it for a very short time, unless your doctor tells you to take it for longer. If you have bought a medicine containing promethazine, do not take it for longer than recommended on the packet without speaking to your pharmacist or doctor first. If you have taken promethazine for a long time and suddenly stop taking it, it's possible you might feel dizzy, sweaty or sick, have a racing heart and have trouble sleeping. Coming off promethazine slowly can help prevent this. Speak to your doctor if you have taken promethazine for a long time and want to stop taking it.