FLUPHENAZINE DECANOATE

FLUPHENAZINE DECANOATE (floo-fen'a-zeen) Prolixin Decanoate, Modecate Decanoate  FLUPHENAZINE ENANTHATE Moditen Enanthate , Prolixin Enanthate FLUPHENAZINE HYDROCHLORIDE Moditen HCl , Permitil, Prolixin Classifications: psychotherapeutic; antipsychotic; phenothiazine; Therapeutic: antipsychotic Prototype: Chlorpromazine Pregnancy Category: C

Availability

1 mg, 2.5 mg, 5 mg, 10 mg tablets; 2.5 mg/5 mL elixir; 5 mg/mL oral concentrate; 2.5 mg/mL, 25 mg/mL injection

Action

Potent phenothiazine, antipsychotic agent. Blocks postsynaptic dopamine receptors in the brain. Similar to other phenothiazines with the following exceptions: more potent per weight, higher incidence of extrapyramidal complications, and lower frequency of sedative, hypotensive, and antiemetic effects.

Therapeutic Effect

Effective for treatment of antipsychotic symptoms including schizophrenia.

Uses

Management of manifestations of psychotic disorders.

Unlabeled Uses

As antineuralgia adjunct.

Contraindications

Known hypersensitivity to phenothiazines; subcortical brain damage, comatose or severely depressed states, blood dyscrasias, renal or hepatic disease; pregnancy (category C), lactation. Parenteral form not recommended for children <12 y.

Cautious Use

With anticholinergic agents, other CNS depressants; older adults, previously diagnosed breast cancer; closed-angle glaucoma; GI disorders; significant pulmonary disease; renal failure; seizure disorders; history of suicidal ideation or high risk for suicide attempt; cardiovascular diseases; pheochromocytoma; history of convulsive disorders; patients exposed to extreme heat or phosphorous insecticides; peptic ulcer; respiratory impairment.

Route & Dosage

Psychosis Adult: PO 0.5–10 mg/d in 1–4 divided doses (max: of 20 mg/d) IM/SC HCl 2.5–10 mg/d divided q6–8h (max: 10 mg/d); Decanoate 12.5–25 mg q1–4wk; Enanthate 25 mg q2wk Dementia Behavior Geriatric: PO 1–2.5 mg/d, may increase every 4–7 d by 1–2.5 mg/d (max: 20 mg/d in 2–3 divided doses)

Administration

• Note: Fluphenazine hydrochloride (HCl) is given PO and IM. Fluphenazine enanthate and decanoate are given IM or SC.

Oral

• Give sustained release tablets whole (need to be swallowed whole; not recommended for children).
• Dilute oral concentrate in fruit juice, water, carbonated beverage, milk, soup. Avoid caffeine-containing beverages (cola, coffee) as a diluent, also tannic acid (tea) or pectinates (apple juice).
• Be careful not to contact skin or clothing with drug when preparing oral concentrate or liquid preparations for injection. Warn patient to avoid spilling drug. If drug contacts skin, rinse/flush skin promptly with warm water.
• Give oral preparations at least 1 h before or 2 h after the antacid. Antacids diminish absorption.
• Protect all preparations from light and freezing. Solutions may safely vary in color from almost colorless to light amber. Discard dark or otherwise discolored solutions.
• Store in tightly closed container at 15°–30° C (59°–86° F) unless otherwise specified by manufacturer. Protect all forms from light.

Adverse Effects (≥1%)

CNS: Extrapyramidal symptoms (resembling Parkinson's disease), tardive dyskinesia, sedation, drowsiness, dizziness, headache, mental depression, catatonic-like state, impaired thermoregulation, grand mal seizures. CV: Tachycardia, hypertension, hypotension. GI: Dry mouth, nausea, epigastric pain, constipation, fecal impaction, cholecystic jaundice. Urogenital: Urinary retention, polyuria, inhibition of ejaculation. Hematologic: Transient leukopenia, agranulocytosis. Skin: Contact dermatitis. Body as a Whole: Peripheral edema. Special Senses: Nasal congestion, blurred vision, increased intraocular pressure, photosensitivity. Endocrine: Hyperprolactinemia.

Interactions

Drug: Alcohol and other cns depressants may potentiate depressive effects; decreases seizure threshold, may need to adjust dosage of anticonvulsants. Herbal: Kava may increase risk and severity of dystonic reactions.

Pharmacokinetics

Absorption: HCl is readily absorbed PO and IM; decanoate, enanthate have delayed IM absorption. Onset: 1 h HCl; 24–72 h decanoate, enanthate. Peak: 0.5 h PO; 1.5–2 h IM HCl. Duration: 6–8 h HCl; 1–6 wk decanoate; 2–4 wk enanthate. Distribution: Crosses blood–brain barrier and placenta. Metabolism: In liver. Half-Life: 15 h HCl; 3.6 d enanthate; 7–10 d decanoate.

Nursing Implications

Assessment & Drug Effects

• Report immediately onset of mental depression and extrapyramidal symptoms. Both occur frequently, particularly with long-acting forms (decanoate and enanthate).
• Be alert for appearance of acute dystonia (see Appendix F). Symptoms can be controlled by reducing dosage or by adding an antiparkinsonism drug such as benztropine.
• Be alert for red, dry, hot skin; full, bounding pulse, dilated pupils, dyspnea, mental confusion, elevated BP, temperature over 40.6° C (105° F). Inform physician and institute measures to reduce body temperature rapidly. Extended exposure to high environmental temperature, to sun's rays, or to a high fever places the patient taking this drug at risk for heat stroke.
• Lab tests: Monitor kidney function in patients on long-term treatment. Withhold drug and notify physician if BUN is elevated (normal BUN: 10–20 mg/dL). Also perform WBC with differential, liver function tests, periodically.
• Monitor BP during early therapy. If systolic drop is more than 20 mm Hg, inform physician.
• Monitor I&O ratio and bowel elimination pattern. Check for abdominal distension and pain. Monitor for xerostomia and constipation.
• Monitor children with routine cardiac studies for signs and symptoms of cardiac adverse effects.
• Note: Patients on large doses who undergo surgery and those with cerebrovascular, cardiac, or renal insufficiency are especially prone to hypotensive effects.

Patient & Family Education

• Do not drive or engage in potentially hazardous activities until response to drug is known.
• Do not alter dosage regimen or stop taking drug abruptly. Do not give drug to any one else.
• Seek and obtain physician approval before taking any OTC drugs.
• Be alert for adverse effects, early detection is critical because both decanoate and enanthate have a long duration of action. Inform physician promptly if following symptoms appear: Light-colored stools, changes in vision, sore throat, fever, cellulitis, rash, any interference with your willful (volitional) movements.
• Make sure to eat and drink adequately in order to prevent constipation and dry mouth.
• Be aware that it may be difficult for you to adjust to extremes in temperature. Use caution because of this possible impaired thermoregulation.
• Avoid exposure to sun; wear protective clothing and cover exposed skin surfaces with sun screen lotion (SPF above 12).
• Avoid alcohol while on fluphenazine therapy.
• Note: Fluphenazine may discolor urine pink to red or reddish brown.
• Periodic ophthalmologic exams are recommended.

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Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug