By mouth. For Adult. 60 mg daily, daily dose may be administered as a single or divided dose. For Elderly. Up to 40 mg daily, daily dose may be administered as a single or divided dose, usual maximum dose is 40 mg daily but doses up to 60 mg daily can be used. Fluoxetine can change the way the body gets rid of other medications. This can make the effect of other medications stronger or weaker. Always check to see if your child’s medication interacts with Fluoxetine. Some medications taken with antidepressants may cause an overload of the brain chemical serotonin. Dangerous side effects such as seizures, overheating, confusion and diarrhoea may. Fluoxetine, brand name Prozac, is an incredibly popular and well-known antidepressant. Prozac is most often prescribed for depression, but can also be used in the treatment of panic disorders, anxiety, obsessive-compulsive disorders, and bulimia. Fluoxetine should not be taken in combination with tamoxifen, used to treat and prevent breast cancer. Fluoxetine can make tamoxifen less effective by affecting its metabolism in the liver. Fluoxetine affects chemicals in the brain that can cause depression, panic, anxiety, or obsessive-compulsive behaviors. It may take up to 3 or 4 weeks before the medication becomes effective. Cautions: Avoid giving other medicines that can make your pet sleepy (cold or allergy medicine, pain medication, muscle relaxants, seizure medicine, or other medications for depression or anxiety). Do not. Prozac (fluoxetine) for Anxiety and Stress: “This drug has been life changing for me, no more anxious or obsessive thoughts. If you are scared to try it please don't be. I can't believe the way I used to think and live life before taking this. Now my thought process have changed and I feel like I am myself again. I sleep better at night, and. Fluoxetine can affect the electrical currents that heart muscle cells use to coordinate their contraction, specifically the potassium currents I to and I Ks that repolarise the cardiac action potential. Under certain circumstances, this can lead to prolongation of the QT interval, a measurement made on an electrocardiogram reflecting how long it takes for the heart to electrically recharge. Can I breastfeed while taking fluoxetine? Most reports find no problems for breastfed babies. In a small number of cases, irritability, vomiting, diarrhea, and less sleep have been reported. One study noted slightly less weight gain in infants exposed to fluoxetine via breast milk; however, this would likely only be an issue if the infant’s weight gain were already a concern. One study. Both fluoxetine and almotriptan can increase the risk of serotonin syndrome. See 'Serotonin syndrome' and 'Monoamine-oxidase inhibitor' under Antidepressant drugs in BNF for more information and for specific advice on avoiding monoamine-oxidase inhibitors during and after administration of other serotonergic drugs. Fluoxetine oral capsule can interact with other medications, vitamins, or herbs you may be taking.An interaction is when a substance changes the way a drug works. This can be harmful or prevent.