What's gonna happen?

My dad takes NyQuil almost every night to help him sleep. Can something happen to him ? Can he have a heart attack?

NyQuil has antihistamines and a small amount of alcohol. I doubt that combination
would cause a heart attack. If he's having trouble sleeping, he should look at the source of that problem rather than depending on a drug. Lack of exercise? Stress? If it continues take him to a doctor.

Agree with Rob.