Steady-state levels after prolonged dosing are similar to levels seen at 4 to 5 weeks. Fluoxetine can increase the level of pimozide through inhibition of CYP2D6. Clinical studies of pimozide with other antidepressants demonstrate an increase in drug interaction or QT prolongation.
- Once released, it stimulates other neurons and is then taken back up into the neuron cells and recycled.
- Do not use Prozac if you have used an MAO inhibitor in the past 14 days (such as isocarboxazid, rasagiline, selegiline, phenelzine, or transcypromine).
- Thus, the dose of TCAs may need to be reduced and plasma TCA concentrations may need to be monitored temporarily when fluoxetine is co-administered or has been recently discontinued see WARNINGS AND PRECAUTIONS (5.2) and CLINICAL PHARMACOLOGY (12.3).
- Because fluoxetine is tightly bound to plasma proteins, adverse effects may result from displacement of protein-bound fluoxetine by other tightly bound drugs see CLINICAL PHARMACOLOGY (12.3).
- Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Prozac only for the indication prescribed.
Additionally, in vitro studies have shown ketoconazole, a potent inhibitor of CYP3A4 activity, to be at least 100 times more potent than fluoxetine or norfluoxetine as an inhibitor of the metabolism of several substrates for this enzyme, including astemizole, cisapride, and midazolam. These data indicate that fluoxetine’s extent of inhibition of CYP3A4 activity is not likely to be of clinical significance. Because fluoxetine is tightly bound to plasma proteins, adverse effects may result from displacement of protein-bound fluoxetine by other tightly bound drugs see CLINICAL PHARMACOLOGY (12.3). Symptoms of sexual dysfunction occasionally persist after discontinuation of fluoxetine treatment. The pupillary dilation that occurs following use of many antidepressant drugs including fluoxetine may trigger an angle closure attack in a patient with anatomically narrow angles who does not have a patent iridectomy.
1 Suicidal Thoughts and Behaviors in Children, Adolescents, and Young Adults
You must wait at least 14 days after stopping an MAO inhibitor before you take fluoxetine. You must wait 5 weeks after stopping fluoxetine before you can take thioridazine or an MAOI. Do not use FLUoxetine (Eqv-PROzac) if you have used an MAO inhibitor in the past 14 days.
Adverse Reactions/Side Effects
It is important to talk with your healthcare provider about the risks of treating depression and also the risks of not treating it. Read the Medication Guide that comes with fluoxetine before you start taking it and each time you get a refill. This Medication Guide does not take the place of talking to your healthcare provider about your medical condition or treatment.
At least 14 days should elapse between discontinuation of an MAOI intended to treat psychiatric disorders and initiation of therapy with fluoxetine. Conversely, at least 5 weeks should be allowed after stopping fluoxetine before starting an MAOI intended to treat psychiatric disorders see CONTRAINDICATIONS (4.1). Prozac is a selective serotonin reuptake inhibitor (SSRI) antidepressant. Fluoxetine affects certain chemical messengers (neurotransmitters) that communicate between brain cells and helps people with depression, panic, anxiety, or obsessive-compulsive symptoms. Do not take fluoxetine with a monoamine oxidase (MAO) inhibitor (eg, isocarboxazid Marplan®, linezolid Zyvox®, methylene blue injection, phenelzine Nardil®, selegiline Eldepryl®, tranylcypromine Parnate®). Do not start taking fluoxetine during the 2 weeks after you stop a MAO inhibitor and wait 5 weeks after stopping fluoxetine before you start taking a MAO inhibitor.
4 Screening Patients for Bipolar Disorder and Monitoring for Mania/Hypomania
Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Prozac only for the indication prescribed. You should not use Prozac if you also take pimozide or thioridazine, or if you are being treated with methylene blue injection. Along with its needed effects, fluoxetine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention. Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter OTC) medicines and herbal (eg, St. John’s wort) or vitamin supplements.
Do not use fluoxetine if you have used an MAO inhibitor in the past 14 days (such as isocarboxazid, rasagiline, selegiline, phenelzine, or transcypromine). This is not a list of all drugs or health problems that interact with this medicine (fluoxetine capsules and tablets). Tell your healthcare provider if you have any side effect that bothers you or that does not go away. For more information, ask your healthcare provider or pharmacist.
- As with all drugs, the potential for interaction by a variety of mechanisms (e.g., pharmacodynamic, pharmacokinetic drug inhibition or enhancement, etc.) is a possibility.
- These side effects may go away during treatment as your body adjusts to the medicine.
- Pulmonary reactions, including inflammatory processes of varying histopathology and/or fibrosis, have been reported rarely.
- Anyone considering the use of fluoxetine in a child or adolescent must balance the potential risks with the clinical need.
Getting the most from your treatment
Hyponatremia has been reported during treatment with SNRIs and SSRIs, including fluoxetine. In many cases, this hyponatremia appears to be the result of the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Cases with serum sodium lower than 110 mmol/L have been reported and appeared to be reversible when fluoxetine was discontinued. Elderly patients may be at greater risk of developing hyponatremia with SNRIs and SSRIs.
In patients with diabetes, fluoxetine may alter glycemic control. Hypoglycemia has occurred during therapy with fluoxetine, and hyperglycemia has developed following discontinuation of the drug. As is true with many other types of medication when taken concurrently by patients with diabetes, insulin and/or oral hypoglycemic, dosage may need to be adjusted when therapy with fluoxetine is instituted or discontinued.
Patients receiving warfarin therapy should be carefully monitored when fluoxetine is initiated or discontinued see WARNINGS AND PRECAUTIONS (5.7). Such monitoring should include daily observation by families and caregivers. Prescriptions for fluoxetine should be written for the smallest quantity of tablets consistent with good patient management, in order to reduce the risk of overdose. Starting fluoxetine in a patient who is being treated with MAOIs such as linezolid or intravenous methylene blue is also contraindicated because of an increased risk of serotonin syndrome see DOSAGE AND ADMINISTRATION (2.7) and WARNINGS AND PRECAUTIONS (5.2). A specific effect on bone development was reported in juvenile mice administered fluoxetine by the intraperitoneal route to 4-week-old mice for 4 weeks at doses 0.5 and 2 times the oral MRHD of 20 mg/day on a mg/m2 basis.
When evaluating changes in sexual function, obtaining a detailed history (including timing of symptom onset) is important because sexual symptoms may have other causes, including the underlying psychiatric disorder. Discuss potential management strategies to support patients in making informed decisions about treatment. Prozac fluoxetine: side effects, dosage, uses, and more and Zoloft represent two of the most widely prescribed antidepressant medications in the United States.
Prozac
As in adults, fluoxetine and norfluoxetine accumulated extensively following multiple oral dosing; steady-state concentrations were achieved within 3 to 4 weeks of daily dosing. In an in vivo interaction study involving co-administration of fluoxetine with single doses of terfenadine (a CYP3A4 substrate), no increase in plasma terfenadine concentrations occurred with concomitant fluoxetine. There have been reports of both increased and decreased lithium levels when lithium was used concomitantly with fluoxetine.
Important information about all medicines
Paxil is used to treat depression, obsessive-compulsive disorder and anxiety. Get emergency medical help if you have signs of an allergic reaction to fluoxetine (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling). Drinking alcohol can increase certain side effects of fluoxetine. Keep using the medication as directed and tell your doctor if your symptoms do not improve.