Fluoxetine

Brand names

• Alti-Fluoxetine
• Apo-Fluoxetine
• Gen-Fluoxetine
• Hydrochloride
• Med-Fluoxetine
• Novo-Fluoxetine
• Nu-Fluoxetine
• PMS-Fluoxetine
• Prozac
• Scheinpharm-Fluoxetine

Usage

To treat major depression, obsessive-compulsive disorder, and bulimia nervosa.

How it works

Fluoxetine affects levels of serotonin, a brain chemical thought to be linked to mood, emotions, and mental state.

Side effects

Serious

Agitation, shaking, difficulty breathing, rash, hives, itching, joint or muscle pain, chills or fever. If such symptoms occur, seek medical help immediately.

Common

Nervousness, drowsiness, anxiety, insomnia, headache, diarrhea, excessive sweating, nausea, decreased appetite, decreased initiative.

Less common

Nasal congestion, unusual or vivid dreams, cough, increased appetite, chest pain, constipation, vision disturbances, abdominal pain, stomach gas, constipation, vomiting, frequent urination, difficulty concentrating, sexual dysfunction, heartbeat irregularities, trembling, fatigue, dizziness, change in taste, flushing of the skin on the face and neck, dry mouth, menstrual pain.

Possible interactions

Other medicaments:

Fluoxetine may increase the effects of:

• beta blockers.
• diazepam (Valium) and other benzodiazepines.
• digitalis preparations (digitoxin, digoxin).
• diltiazem (Cardizem).
• dofetilide (Tikosyn), requiring dosing decreases.
• flecainide (Tambocor).
• phenytoin (Dilantin), or fosphenytoin (Cerebyx) by increasing the phenytoin or fosphenytoin levels.
• propranolol (Inderal).
• quinidine (Quinaglute).
• sildenafil (Viagra), by inhibiting CYP3A4.
• valproic acid (Depakote, others).
• warfarin (Coumadin) and related oral anticoagulants. Test INR more often.

Fluoxetine taken concurrently with:

• antidiabetic medicaments (insulin, oral hypoglycemics) may increase the risk of hypoglycemic reactions; monitor blood sugar levels carefully.
• aspirin (various) caused hives to reappear in a patient allergic to fluoxetine.
• astemizole (Hismanal), terfenadine (Seldane) or similar medicaments may result in increased antihistamine levels and risk of heart arrhythmias. Avoid combining.
• azole antifungals (such as fluconazole, itraconazole and ketoconazole) may lead to higher than expected fluoxetine blood levels and increased risk of adverse effects.
• buspirone (Buspar) may increase underlying anxiety. Combination is best avoided, but if deemed clinically necessary, patients should be closely watched for worsening of symptoms.
• carbamazepine (Tegretol) will increase the carbamazepine level. Medicament levels are critical if the medicaments are combined.
• cimetidine (Tagamet) may theoretically lead to increased fluoxetine levels.
• clarithromycin (Biaxin) may lead to fluoxetine toxicity-avoid the combination.
• clozapine (Clozaril) may result in increased levels of clozapine. The clozapine dose may need to be decreased if both medicines are to be used at the same time.
• delavirdine (Rescriptor) may lead to delavirdine toxicity.
• dextromethorphan (a cough suppressant in many "DM"-labeled nonprescription cough medicines) may result in visual hallucinations if these medicaments are combined. Do not combine these medicines.
• fenfluramine (Pondimin) may lead to serotonin syndrome - do not combine.
• haloperidol (Haldol) will increase haloperidol levels. Dose decrease and blood levels are needed.
• ketorolac (Toradol) may result in hallucinations. Do not take these medicines at the same time.
• lithium (Lithobid, etc.) will result in increased lithium levels and increased risk of neurotoxicity. Avoid the combination.
• loratadine (Claritin) may result in increased loratadine levels. It may be prudent to decrease the loratadine dose if these medicines are to be combined. Unlike some of the other nonsedating antihistamines, loratadine has not resulted in abnormal heart rhythms.
• medicines that inhibit liver metabolism (removal) of this medicine may lead to higher than expected fluoxetine blood levels and increased toxicity risk.
• monoamine oxidase (MAO) type A inhibitor medicaments may cause confusion, agitation, high fever, seizures and dangerous elevations of blood pressure. Avoid combining these medicaments.
• morphine (various) blunted pain management benefits of morphine in one case report.
• naratriptan (Amerge), rizatriptan (Maxalt) , sumatriptan (Imitrex) or zolmitriptan may lead to incoordination and abnormal reflexes. Caution is advised.
• selegiline (Eldepryl) can result in serotonin toxicity syndrome. Avoid this combination.
• sibutramine {Meridia) may lead to serotonin syndrome.
• tramadol (Ultram) may increase seizure risk.
• any tricyclic antidepressant (amitriptyline, nortriptyline, etc.) will result in increased antidepressant medicament levels that will persist for weeks. Avoid the combination.
• tryptophan will result in central nervous system toxicity. Avoid the combination.
• zolpidem (Ambien) may increase risk of hallucinations.

Herbal medicines or minerals:

Since fluoxetine and St. John's wort may act to increase serotonin, the combination is not advised. Since part of the way ginseng works may be as a MAO inhibitor, do not combine with fluoxetine. Ma huang, yohimbe, Indian snakeroot and kava kava are also best avoided while taking this medicine. Calcium now has excellent data (,1200-1,600 mg per day unless contraindicated) in helping prevent premenstrual dysphoric syndrome (PMS). This may be an intelligent first-line therapy or valuable adjunctive use.

Beverages:

Grapefruit juice may lead to increased blood levels.

Discontinuation:

Slow medicament elimination makes withdrawal effects unlikely, but call your doctor if you plan to stop this medicament for any reason.

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