How to use Prozac. Read the Medication Guide provided by your pharmacist before you start using fluoxetine and each time you get a refill. If you have any questions, ask your doctor or pharmacist. Prozac Dosage For people who are first starting bulimia treatment with Prozac, dosing generally starts at 60 mg once a day. For the treatment of depression or obsessive-compulsive disorder, the recommended starting dose is 20 mg once daily. Initial dose: 90 mg orally once a week, commenced 7 days after the last daily dose of immediate-release fluoxetine 20 mg formulations. Comments : -Doses above 20 mg per day may be given in divided doses, in the morning and at noon. Your healthcare provider may need to change the dose of PROZAC until it is the right dose for you. PROZAC may be taken with or without food. If you miss a dose of PROZAC, take the missed dose as soon as you remember.If it is almost time for the next dose, skip the missed dose and take your nextdose at the regular time. La dose initiale est de 10 mg/jour, soit 2,5 ml de PROZAC 20 mg/5 ml, solution buvable. Les ajustements de posologie devront se faire avec précaution, au cas par cas, afin de maintenir le patient à la posologie minimale efficace. Pediatric (children and adolescents) — Initiate PROZAC 10 or 20 mg/day. After 1 week at 10 mg/day, increase the dose to 20 mg/day. However, due to higher plasma levels in lower weight children, the starting and target dose in this group may be 10 mg/day. The starting Prozac dose for children and teens is usually 10 mg or 20 mg once daily. Your child's healthcare provider will take into consideration your child's age, weight, and medical conditions when prescribing an amount for your child. Medscape - Depression, obsessive-compulsive disorder, premenstrual dysphoric disorder-specific dosing for Prozac, Sarafem (fluoxetine), frequency-based adverse effects, comprehensive interactions, contraindications, pregnancy & lactation schedules, and cost information. If we assume a fairly uniform dose-dependent response to antidepressants, we can estimate the potency of 40mg of Prozac (used as a single-drug treatment for unipolar depression, in this context) as compared to doses of other antidepressants. Prozac is the brand name of fluoxetine, a prescription drug used to treat depression. This antidepressant is in a class of drugs known as selective serotonin reuptake inhibitors, or SSRIs.