Usually, your doctor informs you about the possible side effects that you may develop. However, it is important to note that these side effects are very rare, and range from mild to severe. It is thus important to promptly inform your doctor if any of the following side effects occur: Severe headaches, Stomach upsets, Vomiting, Diarrhea, Unexplained weight loss, Signs of allergic reactions such as rashes, Join pain, Vision changes, Signs of infection like swollen lymph nodes, Signs of hyperthyroidism, Signs of Guillain-Barre Syndrome There might be other side effects as well that have not been enlisted here. For further queries, you may consult your healthcare provider.