FLUPHENAZINE

(floo fen' a zeen)

fluphenazine decanoate

Injection: Modecate Deconoate (CAN), Prolixin Decanoate, Rho-Fluphenazine Deconate (CAN)

fluphenazine enanthate

Injection: Moditen Enanthate (CAN), PMS-Fluphenazine (CAN)

fluphenazine hydrochloride

Oral tablets, concentrate, elixir, injection: Apo-Fluphenazine (CAN), Moditen Hydrochloride (CAN), Permitil, PMS-Fluphenazine (CAN)
PREGNANCY CATEGORY C

Drug classes
Therapeutic actions
Indications
Contraindications and cautions
Available forms
Dosages
  Fluphenazine hydrochloride
  Oral
  IM
  Fluphenazine enanthate, fluphenazine decanoate
Pharmacokinetics
Adverse effects
Indications
  Drug-drug
  Drug-lab test
Nursing considerations Assessment
Interventions
Teaching points

 

Drug classes

Phenothiazine

Dopaminergic blocking agent

Antipsychotic

Therapeutic actions

Mechanism not fully understood: antipsychotic drugs block postsynaptic dopamine receptors in the brain, depress the RAS, including the parts of the brain involved with wakefulness and emesis; anticholinergic, antihistaminic (H 1), and alpha-adrenergic blocking activity also may contribute to some of its therapeutic (and adverse) actions.

Indications

• Management of manifestations of psychotic disorders; the longer acting parenteral dosage forms, fluphenazine enanthate and fluphenazine decanoate, indicated for management of patients (chronic schizophrenics) who require prolonged parenteral therapy
• Management of behavioral complications in patients with mental retardation (fluphenazine decanoate)

Contraindications and cautions

• Contraindicated with coma or severe CNS depression, bone marrow depression, blood dyscrasia, circulatory collapse, subcortical brain damage, Parkinson's disease, liver damage, cerebral arteriosclerosis, coronary disease, severe hypotension or hypertension; pregnancy.
• Use cautiously with respiratory disorders (“silent pneumonia”); glaucoma, prostatic hypertrophy (anticholinergic effects may exacerbate glaucoma and urinary retention); epilepsy or history of epilepsy (drug lowers seizure threshold); breast cancer (elevations in prolactin may stimulate a prolactin-dependent tumor); thyrotoxicosis; peptic ulcer, decreased renal function; myelography within previous 24 hr or myelography scheduled within 48 hr; exposure to heat or phosphorous insecticides; pregnancy; lactation; children younger than 12 yr, especially those with chickenpox, CNS infections (children are especially susceptible to dystonias that may confound the diagnosis of Reye's syndrome).

Available forms

Tablets—1, 2.5, 5, 10 mg; injection—25 mg/mL

Dosages

Full clinical effects may require 6 wk–6 mo of therapy. Patients who have never taken phenothiazines, “poor-risk” patients (those disorders that predispose to undue reactions) should be treated initially with this shorter acting dosage form and then switched to the longer acting parenteral forms, fluphenazine enanthate or decanoate.

The duration of action of the esterified forms of fluphenazine is markedly longer than those of fluphenazine hydrochloride; the duration of action of fluphenazine enanthate is estimated to be 1–3 wk; the duration of action of fluphenazine decanoate is estimated to be 4 wk. No precise formula is available for the conversion of fluphenazine hydrochloride dosage to fluphenazine decanoate dosage, but one study suggests that 20 mg of fluphenazine hydrochloride daily was equivalent to 25 mg decanoate every 3 wk.

Fluphenazine hydrochloride

Adults
Individualize dosage, begin with low dosage, gradually increase.
• Oral

0.5–10 mg/day in divided doses q 6–8 hr; usual daily dose is less than 3 mg. Give daily doses greater than 20 mg with caution. When symptoms are controlled, gradually reduce dosage.

• IM

Average starting dose is 1.25 mg (range 2.5–10 mg), divided and given q 6–8 hr; parenteral dose is one-third to one-half the oral dose. Give daily doses greater than 10 mg with caution.

Pediatric patients
Generally not recommended for children < 12 yr.

Geriatric patients
Initial oral dose is 1–2.5 mg/day.

Fluphenazine enanthate, fluphenazine decanoate

Adults
•  Initial dose: 12.5–25 mg IM or SC; determine subsequent doses and dosage interval based on patient response. Dose should not exceed 100 mg.

Pharmacokinetics


Route Onset Peak Duration
Oral 60 min 2 hr 6–8 hr
IM (HCl) 60 min 1–2 hr 6–8 hr
IM (enanthate) 24–72 hr   2 wk
IM (decanoate) 24–72 hr   1–6 wk

Metabolism: Hepatic; T ½: 4.5–15.3 hr (fluphenazine hydrochloride), 3.7 days (fluphenazine enanthate), 6.8–9.6 days (fluphenazine decanoate)

Distribution: Crosses placenta; enters breast milk

Excretion: Unchanged in the urine

Adverse effects

Adverse effects in Italics are most common; those in Bold are life-threatening.

•  Autonomic: Dry mouth, salivation, nasal congestion, nausea, vomiting, anorexia, fever, pallor, flushed facies, sweating, constipation, paralytic ileus, urinary retention, incontinence, polyuria, enuresis, priapism, ejaculation inhibition, male impotence
•  CNS: Drowsiness, insomnia, vertigo, headache, weakness, tremor, ataxia, slurring, cerebral edema, seizures, exacerbation of psychotic symptoms, extrapyramidal syndromes (pseudoparkinsonism); dystonias; akathisia, tardive dyskinesias, potentially irreversible, neuroleptic malignant syndrome (extrapyramidal symptoms), hyperthermias, autonomic disturbances (rare, but 20% fatal)
•  CV: Hypotension, orthostatic hypotension, hypertension, tachycardia, bradycardia, cardiac arrest, CHF, cardiomegaly, refractory arrhythmias, pulmonary edema
•  Endocrine: Lactation, breast engorgement in females, galactorrhea; syndrome of inappropriate ADH secretion; amenorrhea, menstrual irregularities; gynecomastia in males; changes in libido; hyperglycemia or hypoglycemia; glycosuria; hyponatremia; pituitary tumor with hyperprolactinemia; inhibition of ovulation, infertility, pseudopregnancy; reduced urinary levels of gonadotropins, estrogens, progestins
•  Hematologic: Eosinophilia, leukopenia, leukocytosis, anemia; aplastic anemia; hemolytic anemia; thrombocytopenic or nonthrombocytopenic purpura; pancytopenia
•  Hypersensitivity: Jaundice, urticaria, angioneurotic edema, laryngeal edema, photosensitivity, eczema, asthma, anaphylactoid reactions, exfoliative dermatitis
•  Respiratory: Bronchospasm, laryngospasm, dyspnea; suppression of cough reflex and potential for aspiration (sudden death related to asphyxia or cardiac arrest has been reported)

Indications

Drug-drug

• Additive CNS depression with alcohol
• Additive anticholinergic effects and possibly decreased antipsychotic efficacy with anticholinergic drugs
• Increased likelihood of seizures with metrizamide (contrast agent used in myelography)
• Decreased antihypertensive effect of guanethidine with antipsychotic drugs

Drug-lab test

• False-positive pregnancy tests (less likely if serum test is used)
• Increase in PBI, not attributable to an increase in thyroxine

Nursing considerations Assessment

•  History: Coma or severe CNS depression; bone marrow depression; blood dyscrasia; circulatory collapse; subcortical brain damage; Parkinson's disease; liver damage; cerebral arteriosclerosis; coronary disease; severe hypotension or hypertension; respiratory disorders; glaucoma, prostatic hypertrophy; epilepsy; breast cancer; thyrotoxicosis; peptic ulcer, decreased renal function; myelography within previous 24 hr or myelography scheduled within 48 hr; exposure to heat or phosphorous insecticides; children < 12 yr, chickenpox, CNS infections; pregnancy
•  Physical: Weight, T; reflexes, orientation, intraocular pressure; P, BP, orthostatic BP; R, adventitious sounds; bowel sounds and normal output, liver evaluation; urinary output, prostate size; CBC, urinalysis, thyroid, liver and kidney function tests

Interventions

• Arrange for discontinuation of drug if serum creatinine, BUN become abnormal or if WBC count is depressed.
• Monitor elderly patients for dehydration, institute remedial measures promptly. Sedation and decreased sensation of thirst related to CNS effects can lead to severe dehydration.
• Consult physician regarding appropriate warning of patient or patient's guardian about tardive dyskinesias.
• Consult physician about dosage reduction, use of anticholinergic antiparkinsonian drugs (controversial) if extrapyramidal effects occur.

Teaching points

• Take drug exactly as prescribed.
• Avoid driving or engaging in other dangerous activities if CNS, vision changes occur.
• Avoid prolonged exposure to sun; use a sunscreen or covering garments if exposure is unavoidable.
• Maintain fluid intake, and use precautions against heatstroke in hot weather.
• Report sore throat, fever, unusual bleeding or bruising, rash, weakness, tremors, impaired vision, dark urine (pink or reddish brown urine is expected), pale stools, yellowing of skin or eyes.


Copyright © 2004 Lippincott Williams & Wilkins
Amy M. Karch
2004 Lippincott's Nursing Drug Guide