Contains #1 Doctor Recommended Ingredient: Diphenhydramine HCl 25 mg. Sominex is a nighttime sleep aid designed to help you wake up relaxed and refreshed. Single Dose, 32 caplets per box. Contains #1 Doctor Recommended Ingredient: Diphenhydramine HCl 25 mg. Sominex is a nighttime sleep aid designed to help you wake up relaxed and refreshed. Single Dose, 16 caplets per box. As a night-time sleep aid, for the correction of temporary disturbances of sleep pattern where there is difficulty in going to sleep or staying asleep, caused for example by specific dislocation of normal routine. Sominex should not be used in pregnancy unless the physician considers it essential. The use of Sominex is not recommended in the 2 weeks prior to delivery in view of the risk of irritability and excitement in the neonate. Available evidence suggests that the amount excreted in milk is insignificant. However, there are risks of neonatal irritability and excitement. This product causes drowsiness. Do not drive or operate machinery. Cause drowsiness. Do not drive or operate machinery. Not to be used for more than 7 days without medical advice. In patients with asthma or other respiratory disorders (eg bronchitis or bronchiectasis), glaucoma, epilepsy, urinary retention, prostatic hypertrophy, hepatic or renal impairment, cardiovascular problems or pyloroduodenal obstruction the product should only be taken after consulting a doctor.