As with any drug, there is a possibility of side effects while using this medication. Minor adverse reactions that have been reported by patients include congestion, throat irritation or swallowing problems, headaches, tremors, or an increased nervous state. Some side effects that should be reported to the appropriate medical personnel are as follows: difficulty breathing, chest pain, heightened or lowered heart rate, pronounced asthma symptoms, muscle cramps, fevers, choking, or headaches that are severe.