Sominex tablets are for those occasions when you struggle to get to sleep because your usual routine is disturbed. Sominex tablets are one a night dose tablets, they contain Promethazine Hydrochloride, which induces drowsiness. This effective medication is safe and effective in helping you to fall asleep. Sominex has been clinically tested and proved to relieve occasinol sleeplessness. This treatment if recommended for ‘Short Trem’ use only.