Slight drowsiness/dizziness, nausea, or vomiting may occur. Rarely, some people may experience severe drowsiness/dizziness with normal doses. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Will Robitussin help me sleep?

Robitussin Nighttime Cough Dm (Dextromethorphan / Doxylamine) is a combination medicine that relieves multiple cold symptoms. It's good to use if you have watery eyes, sneezing, and a cough. The antihistamine (doxylamine) helps you fall asleep and doesn't make you feel groggy the next morning.

Does Robitussin cough and chest congestion make you sleepy?

Before using this medication, tell your doctor or pharmacist your medical history, especially of: breathing problems (such as emphysema, chronic bronchitis, asthma, smoker's cough), cough with blood or large amounts of mucus, liver problems. This drug may make you dizzy or drowsy.