Classifications: psychotherapeutic; phenothiazine antipsychotic; Therapeutic: antipsychotic
Pregnancy Category: C
1 mg, 2 mg, 5 mg, 10 mg, 20 mg capsules; 5 mg/mL solution
Xanthene derivative and a phenothiazine. Mechanism of antipsychotic effects is thought to be related to blockade of postsynaptic
dopamine receptors in the brain.
Possesses antipsychotic, sedative, adrenolytic, and antiemetic activity.
Manifestations of psychotic disorders.
Hypersensitivity to thioxanthenes and phenothiazines; children <12 y; comatose states; CNS depression; circulatory collapse;
blood dyscrasias; pregnancy (category C), lactation.
History of convulsive disorders; alcohol withdrawal; glaucoma; prostatic hypertrophy; cardiovascular disease; patients who
might be exposed to organophosphorus insecticides or to extreme heat; concomitant use of atropine or related drugs or ototoxic
medications (especially ototoxic antibiotics); previously diagnosed breast cancer.
Route & Dosage
Adult: PO 2 mg t.i.d., may increase up to 15 mg/d as needed or tolerated (max: 60 mg/d) IM 4 mg b.i.d. to q.i.d. (max: 30 mg/d)
Geriatric: PO 12 mg 12 times/d, may increase q47d (max: 30 mg/d in divided doses)
- Avoid contact between oral concentrate and skin or clothing to prevent contact dermatitis. If concentrate spills, wash skin
promptly with water.
- Give oral concentrate (contains 7% alcohol) diluted in a cupful of water, fruit juice, carbonated beverage, milk, or
- Empty capsule and give with water or mix with food; useful if patient unable or unwilling to swallow the capsule.
- Give IM injection deep into upper outer quadrant of buttock. Aspirate carefully before injection. Rotate injection sites.
- Do not permit access to more than one dose of medication if patient has suicidal tendency; supervise ingestion to prevent
- Store at 15°30° C (59°86° F) in light-resistant containers unless otherwise indicated.
Adverse Effects (≥1%)CNS: Drowsiness, insomnia
, dizziness, cerebral edema, convulsions, extrapyramidal symptoms (dose related),
paradoxical exaggeration of psychotic symptoms; sudden death, neuroleptic malignant syndrome,
tardive dyskinesia, depressed cough reflex. GI:
Tachycardia, orthostatic hypotension
(especially with IM). Urogenital:
Impotence, gynecomastia, galactorrhea, amenorrhea. Skin:
Rash, contact dermatitis, photosensitivity. Special Senses:
Blurred vision, pigmentary retinopathy. Metabolic:
Decreased serum uric acid levels.
InteractionsDrug: Alcohol, anxiolytics
, other cns depressants
add to CNS depression; additive adverse effects with other phenothiazines
; Herbal: Kava
may increase risk and severity of dystonic reactions.
Slowly absorbed from GI tract. Onset:
Days to weeks PO; 16 h IM. Duration:
Up to 12 h. Distribution:
May remain in body for several weeks; crosses placenta. Metabolism:
In liver. Elimination:
In bile and feces. Half-Life:
Assessment & Drug Effects
- Monitor for therapeutic response. Although therapeutic response can be observed 16 h following IM injection, it may
be days or several weeks before there is a response with oral drug.
- Keep patient recumbent for at least 1 h following IM because of possibility of orthostatic hypotension. Check BP periodically.
- Monitor BP for excessive hypotensive response when thiothixene is added to drug regimen of patient on hypertensive treatment
until therapy is stabilized.
- Monitor response when patient is changed from IM to PO forms (capsules, concentrate). Dosage adjustment may be necessary.
- Monitor infants delivered from mothers who have received thiothixene. Hyperreflexia has been reported.
- Lab tests: Periodic blood chemistry and liver function tests with prolonged therapy.
- Report extrapyramidal effects (pseudoparkinsonism, akathisia, dystonia) to physician; dose adjustment or short-term therapy
with an antiparkinsonism agent may provide relief.
- Be alert to first symptoms of tardive dyskinesia (see Appendix F). Discontinue drug immediately and inform physician.
Patient & Family Education
- Make position changes slowly, particularly from lying down to upright because of danger of light-headedness; sit a few minutes
- Do not drive or engage in potentially hazardous activities until response to drug is known.
- Avoid alcohol and other depressants during therapy.
- Take drug as prescribed; do not alter dosing regimen or stop medication without consulting physician. Abrupt discontinuation
can cause delirium.
- Do not use any OTC drugs without approval of physician.
- Note: Hyperhidrosis, while an uncomfortable adverse effect, does not indicate need to terminate therapy.
- Avoid excessive exposure to sunlight to prevent a photosensitivity reaction. If sun exposure is expected, protect skin with
sunscreen lotion (SPF 12 or above).
- Schedule periodic eye exams and report blurred vision to physician.