How Ephedrine, Hydroxyzine, and Theophylline work Ephedrine, Hydroxyzine, and Theophylline is a combination of three medicines.
Common side effects of Ephedrine, Hydroxyzine, and Theophylline include nausea, dryness in the mouth, vomiting, stomach discomfort, anxiety, headache, increased heart rate, restlessness, drowsiness, and insomnia (difficulty sleeping).