Prozac

Prozac

 [pro´zak]

trademark for preparations of fluoxetine hydrochloride, an antidepressant.

fluoxetine hydrochloride

Prozac, Prozac Weekly, Prozit (UK), Sarafem

Pharmacologic class: Selective serotonin reuptake inhibitor

Therapeutic class: Antidepressant

Pregnancy risk category B

Action

Selectively inhibits serotonin reuptake in CNS; has little to no effect on norepinephrine and dopamine reuptake

Availability

Capsules: 10 mg, 15 mg, 20 mg, 40 mg

Capsules (delayed-release): 90 mg

Oral solution: 20 mg/5 ml

Tablets: 10 mg, 15 mg, 20 mg

Indications and dosages

➣ Major depressive disorder (MDD)

Adults: 20 mg/day P.O. in morning. After several weeks, may increase by 20 mg/day at weekly intervals. Give dosages above 20 mg/day in two divided doses (morning and noon); don't exceed 80 mg/day. Patients stabilized on 20 mg/day may be switched to 90-mg/week delayed-release capsules (Prozac Weekly) 7 days after last 20-mg dose.

Children ages 8 to 18: Initially, 10 to 20 mg/day P.O. After 1 week at 10 mg daily, dosage should be increased to 20 mg/day. However, because of higher plasma levels in lower-weight children, starting and target dose in this group may be 10 mg/day. Dosage increase to 20 mg/day may be considered after several weeks if insufficient clinical improvement occurs.

➣ Obsessive-compulsive disorder (OCD)

Adults: Initially, 20 mg/day P.O. in morning. After several weeks, may increase dosage. Give doses above 20 mg/day once daily (morning) or in two divided doses b.i.d. (morning and noon). Dosage range of 20 to 60 mg/day is recommended; however, dosages of up to 80 mg/day have been well tolerated. Don't exceed 80 mg/day.

Children ages 7 to 17: Initially, 10 mg/day P.O. in morning in adolescents and higher-weight children; after 2 weeks, may increase dosage to 20 mg/day. Additional dosage increases may be considered after several more weeks if insufficient clinical improvement occurs. Dosage range of 20 to 60 mg/day is recommended. Initially, 10 mg/day P.O. in lower-weight children; may increase dosage after several more weeks if insufficient clinical improvement occurs. Dosage range of 20 to 30 mg/day is recommended. Experience with daily doses greater than 20 mg is very minimal; there is no experience with doses greater than 60 mg.

➣ Acute treatment of depressive episodes associated with bipolar I disorder

Adults: Initially, 20 mg fluoxetine P.O. with 5 mg olanzapine P.O. daily; dosage range of fluoxetine is 20 to 50 mg; olanzapine, 5 to 12.5 mg. Safety of fluoxetine doses above 75 mg and olanzapine doses above 18 mg haven't been established

➣ Bulimia nervosa

Adults: 60 mg/day P.O.; may be titrated upward over several days

➣ Panic disorder

Adults: 10 mg/day P.O. for 1 week; then, if needed, increase to 20 mg/day. Dosage increases of up to 60 mg/day may be considered after several weeks if patient doesn't respond to lower dosage.

➣ Premenstrual dysphoric disorder

Adults: 20 mg/day (Sarafem) P.O., not to exceed 80 mg/day

Dosage adjustment

• Hepatic impairment

• Concurrent disease or multiple concomitant medications

• Pregnant women during third trimester

• Elderly patients

Off-label uses

• Diabetic peripheral neuropathy

• Alcoholism

• Bipolar II disorder

• Borderline personality disorder

• Narcolepsy

• Posttraumatic stress disorder

• Schizophrenia

• Social phobia

Contraindications

• Hypersensitivity to drug

• MAO inhibitor use within past 14 days

• Concurrent use of thioridazine or within 5 weeks of discontinuing fluoxetine

• Concurrent use of pimozide

Precautions

Use cautiously in:

• hepatic or renal impairment, diabetes mellitus, cardiovascular disease, concomitant illness, acute narrow-angle glaucoma

• history of seizures, serotonin syndrome or neuroleptic malignant syndrome, clinical worsening and suicidal thinking and behavior, activation of mania or hypomania

• hyponatremia in association with syndrome of inappropriate antidiuretic hormone secretion

• concurrent use of NSAIDs, aspirin, warfarin, or other drugs that affect coagulation

• concurrent use of tryptophan (use not recommended)

• pregnant patients (third trimester)

• breastfeeding patients (use not recommended)

• children younger than age 7 (in OCD use), younger than age 8 (in MDD use), younger than age 18 for all other uses (safety and efficacy not established).

Administration

☞ Be aware that drug should be discontinued 5 weeks before MAO inhibitor or thioridazine therapy begins.

• Give before 2 P.M. to prevent nighttime insomnia.

• Be aware that drug should be gradually reduced rather than abruptly stopped whenever possible.

Adverse reactions

CNS: anxiety, drowsiness, headache, insomnia, abnormal dreams, dizziness, fatigue, nervousness, hypomania, mania, weakness, tremor, seizures, suicidal ideation

CV: chest pain, palpitations, prolonged QTc interval

EENT: visual disturbances, stuffy nose, sinusitis, pharyngitis

GI: nausea, vomiting, diarrhea, constipation, abdominal pain, dyspepsia, dry mouth, anorexia

GU: urinary frequency, sexual dysfunction, dysmenorrhea

Metabolic: hypouricemia, hypocalcemia, hyponatremia, hyperglycemia, hypoglycemia

Musculoskeletal: joint, back, or muscle pain

Respiratory: cough, upper respiratory tract infection, dyspnea, respiratory distress

Skin: diaphoresis, pruritus, erythema nodosum, flushing, rash

Other: abnormal taste, weight loss, fever, flulike symptoms, hot flashes, serotonin syndrome, neuroleptic malignant syndrome (NMS), allergic reactions, hypersensitivity reactions

Interactions

Drug-drug. Adrenergics: increased sensitivity to adrenergics, increased risk of serotonin syndrome

Alprazolam: decreased metabolism and increased effects of alprazolam

Antihistamines, opioids, other antidepressants, sedative-hypnotics: additive CNS depression

Aspirin, NSAIDs, warfarin, other drugs that affect coagulation: increased risk of GI or other bleeding

Buspirone: potentiation of fluoxetine effects, increased risk of seizures

Carbamazepine, clozapine, digoxin, haloperidol, lithium, phenytoin, warfarin: increased blood levels of these drugs, greater risk of adverse reactions

CYP450-2D6 inducers: increased effects of these drugs

Cyproheptadine: decrease in or reversal of fluoxetine effects

Digoxin, warfarin, other highly protein-bound drugs: increased risk of adverse reactions to either drug

Efavirenz, ritonavir, saquinavir, other CYP450 inhibitors: serotonergics, triptans: increased risk of serotonin syndrome

MAO inhibitors: confusion, agitation, seizures, hypertension, and hyperpyrexia (serotonin syndrome)

Pimozide: increased risk of drug interaction or QTc-interval prolongation

Thioridazine: increased risk of QTc-interval prolongation or potential for elevated thioridazine plasma level

Other antidepressants, phenothiazines, risperidone, tryptophan: increased risk of adverse reactions

Ritonavir: increased ritonavir blood level

Drug-diagnostic tests. Alanine aminotransferase, alkaline phosphatase, blood urea nitrogen, creatine kinase, electrolytes, glucose: increased levels

Sodium: decreased level

Drug-herbs. St. John's wort: increased risk of serotonin syndrome

Drug-behaviors. Alcohol use: additive CNS depression

Patient monitoring

☞ Monitor patient for signs and symptoms of depression. Assess for suicidal ideation.

☞ Evaluate neurologic status, watching especially for seizures.

☞ Monitor cardiovascular status, particularly for prolonged QTc interval.

• Assess weight regularly. Watch for signs of eating disorders.

☞ Monitor patient for signs and symptoms of allergic reactions, serotonin syndrome, or NMS-like reactions. Discontinue drug immediately and initiate supportive treatment if these reactions occur.

Patient teaching

• Encourage patient to establish effective bedtime routine to minimize sleep disorders.

• Tell patient drug may take 4 weeks or longer to be fully effective.

☞ Instruct patient to contact prescriber if he develops worsening depression or has suicidal thoughts.

☞ Instruct patient to immediately stop drug and report signs and symptoms of allergic reactions (rash), serotonin syndrome, or neuroleptic malignant syndrome-like reactions.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.

• Tell female patient to inform prescriber if she is pregnant or breastfeeding.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, herbs, and behaviors mentioned above.

Prozac

(prō′zăk′)

A trademark for the hydrochloride salt of the drug fluoxetine.

Prozac®

Fluoxetine Neuropharmacology An oral selective serotonin reuptake inhibitor–SSRI used for depression, obsessive-compulsive disorder, bulimia nervosa Adverse effects 10-15% of Pts experience anxiety, nervousness, insomnia, weight loss, overstimulation, upset stomach, headache Contraindications MAOI therapy. See SSRI–serotonin-selective reuptake inhibitor.

Prozac

A brand name for FLUOXETINE. This widely used mood-controlling drug can interact dangerously with drugs of the MAO inhibitor group and some other antidepressants.