In rare cases, some patients have developed a sever muscle condition that can be very serious. A user who experiences tenderness, pain, or weakness of the muscles must report the condition immediately to a physician. Additional side effects that may require medical intervention include the following reactions: nausea, fever, stomach problems, tiredness, and vomiting. Less serious adverse reactions that may be exhibited are joint pain, gas, indigestion, rashes on the skin, and pronounced bloating.