If you experience any symptoms associated with allergies such as difficulty breathing, hives, swollen tongue etc., stop using the medication and seek urgent medical help.
Contact a medical specialist immediately if you experience any of the following: mood swings, behavioral changes, anxiety, panic attacks, insomnia, irritability, agitation, hostility feelings, aggressiveness, restlessness, hyperactivity, depression, suicidal thoughts, seizures, increased heartbeat, fever, swollen glands, skin pain, red or purple skin rash in the upper body, itching, pain in the joints, blistering, peeling, burning sensation in the eyes, or sore throat.
Common side effects of using Zyban include mouth dryness, nausea, pain in the stomach, headaches, dizziness, reduced libido, muscle pain, sore throat, skin itching or rash, frequent urination, appetite changes, weight loss or gain.
Note that this list does not include all possible side effects. Other side effects might occur depending on individual health conditions.