Category:

• Miscellaneous

Description:

• Antiemetic, antipsychotic

Indications:

• Severe nausea and vomiting

• Psychotic disorders

Contraindications:

• Severe toxic CNS depression, coma, subcortical brain damage, bone marrow depression

• Severe liver or cardiac disease, narrow-angle glaucoma, pediatric surgery

Precautions:

• Pregnancy category C; evidence indicates safety in low doses; expect sedation in nursing infants

• Children <5 years, prolonged use, cardiovascular disease, epilepsy

• Hepatic or renal disease, glaucoma, prostatic hypertrophy, severe asthma

• Emphysema, hypocalcemia, thyrotoxicosis, tartrazine sensitivity

Adverse Reactions (Side Effects):

• CNS: agitation, anxiety, catatonic-like behavioral states, confusion, depression, drowsiness, EPS, euphoria, exacerbation of psychotic symptoms including hallucinations, headache, heat or cold intolerance, insomnia, lethargy, neuroleptic malignant syndrome, restlessness, seizures, vertigo

• CV: ECG changes, hypertension, hypotension, tachycardia

• EENT: blurred vision, cataracts, dry eyes, dry mouth, glaucoma, pigmentaion of retina or cornea, retinopathy

• GI: anorexia, constipation, diarrhea, dyspepsia, hypersalivation, nausea, vomiting

• GU: priapism, urinary retention

• HEME: agranulocytosis, anemia, aplastic anemia, hemolytic anemia, leukocytosis, transient leukopenia

• METAB: breast engorgement, gynecomastia, hyperglycemia, hyperprolactinemia, hypoglycemia, hyponatremia, impotence, increased libido, lactation, mastalgia, menstrual irregularities

• RESP: bronchospasm, increased depth of respiration, laryngospasm

• SKIN: diaphoresis, loss of hair, maculopapular and acneiform skin reactions, photosensitivity

Dosage:

Administered orally, intramuscularly, intravenously, rectally

• Adult:            

  • Antiemetic: PO 5-10mg 3-4 times daily, usual max 40mg daily; PO extended release 10mg 2 times daily or 15mg once daily; IM 5-10mg every 3-4 hours, usual max 40mg daily; IV 2.5-10mg every 3-4 hours, max 10mg per dose, 40 mg/day; PR 25mg 2 times daily

  • Psychosis: PO 5-10mg 3-4 times daily, increase dose as needed, max 150mg daily; IM 10-20mg every 4 hours as needed, convert to PO as soon as possible

• Child:            

  • Antiemetic: PO/PR 9-14kg: 2.5mg every 12 –24 hours, max 7.5mg daily; 14-18kg: 2.5mg every 8 hours or 5mg every 12 hours, max 15mg daily; IM 0.1-0.5 mg/kg/dose, convert to PO as soon as possible

  • Psychosis: PO/PR 2-12 years: 2.5mg 2-3 times daily, increase dose as needed, max 20mg daily; 2-5 years: 25mg daily; IM 6-12 years: 0.13 mg/kg/dose, convert to PO as soon as possible

Drug interactions:

·        Levodopa: inhibited effect of levodopa on Parkinson’s disease

·        Indomethacin: possible increased CNS side effects, other NSAIDs less likely to have effect

·        Narcotic analgesics: excessive CNS depression, hypotension, respiratory depression