Prozac (fluoxetine) is a prescription drug intended for the treatment of conditions caused by the imbalance of chemicals in the brain. The following conditions can be treated with Prozac: depression, premenstrual dysphoric disorder symptoms, some eating disorders, panic attacks, and obsessive-compulsive disorder. Some 4 weeks may be required for you to feel the benefits of using Prozac - you will need to take this drug regularly even if you do not feel better at start. Never take more of Prozac at once - even if you missed a dose. In that case it's better to skip the dose missed, as taking more can produce such symptoms as pounding heartbeat, dizziness, unsteadiness, unresponsiveness, nervousness, fainting, fever, or confusion. Those symptoms indicate an overdose and you will need to seek emergency medical help if you get any of them while using Prozac. Make sure you report any of the following serious side effects of Prozac that are unlikely but still possible: hives, swelling of the face, throat, tongue, lips etc., confusion, fever, irregular heartbeat, hallucinations, difficulty breathing or swallowing, joint pain, severe muscle stiffness, and rash.