Headache, nausea, vomiting, tiredness, muscle pain, or weakness may occur.
Serious side effects including nausea/vomiting that doesn't stop, development of a limp, unusual tiredness, unusual/unexplained weight gain, cold intolerance, fast/slow heartbeat, ear pain/itching, hearing problems, joint/hip/knee pain, numbness/tingling, unusual increase in thirst or urination, swelling hands/ankles/feet, change in the appearance or size of any mole, severe stomach/abdominal pain.
Rare (possibly fatal) lung/breathing problems may be caused by this medication in children with Prader-Willi syndrome. Those at higher risk include males, severely overweight children, or those with serious lung/breathing problems ( such as sleep apnea, lung infections, lung disease).