This medication is not without any side effects, but some side effects such as dry mouth, insomnia, dizziness, nausea, diarrhea, and fatigue can be expected as your body adjusts. If you experience the following persistently, inform your doctor: Chest pain, Fainting, Fast heartbeat, Agitation and confusion, Muscle pain, Severe headaches, Weight loss, Vision issues, Seizures, Allergic reactions like rashes, itching, and swelling. If you see rainbows around lights at night or experience muscle tenderness, seek immediate medical attention. You may see empty tablets in your stool; this is harmless.