SPARINE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for SPARINE (SPARINE).
Phenothiazine antipsychotic; blocks postsynaptic mesolimbic dopaminergic D1 and D2 receptors; also blocks alpha-adrenergic receptors, and has anticholinergic and antihistaminergic effects.
| Metabolism | Primarily hepatic via CYP2D6 and other unidentified pathways; active metabolites include glucuronide conjugates. |
| Excretion | Primarily renal (70-80% as metabolites, less than 1% unchanged); biliary/fecal (15-30%) |
| Half-life | Terminal elimination half-life: 10-20 hours; clinical context: allows once or twice daily dosing; extended in elderly and hepatic impairment |
| Protein binding | 92-96% bound primarily to albumin and alpha-1 acid glycoprotein |
| Volume of Distribution | Vd: 10-15 L/kg; high value indicates extensive tissue distribution |
| Bioavailability | Oral: 30-40% due to first-pass metabolism; IM: 90-100%; IV: 100% |
| Onset of Action | Oral: 30-60 minutes; IM: 15-30 minutes; IV: 5-10 minutes |
| Duration of Action | Oral: 4-6 hours; IM: 4-6 hours; IV: 4-6 hours; clinical note: duration shorter for antipsychotic effect; longer for antiemetic effect |
Promazine hydrochloride: 25-50 mg intramuscularly or intravenously every 4-6 hours as needed; maximum 300 mg/day. Alternatively, oral: 25-200 mg every 4-6 hours; maximum 1000 mg/day. Route and frequency depend on indication and patient response.
| Dosage form | CONCENTRATE |
| Renal impairment | In patients with GFR 10-50 mL/min: administer 75% of normal dose. If GFR <10 mL/min: administer 50% of normal dose. Monitor for excessive sedation and hypotension. |
| Liver impairment | Child-Pugh Class A: no adjustment necessary. Child-Pugh Class B: reduce dose by 25-50%. Child-Pugh Class C: contraindicated or use with extreme caution; reduce dose by 75% and monitor closely. |
| Pediatric use | Children >6 months: 0.5-1 mg/kg intramuscularly or intravenously every 4-6 hours; maximum 50 mg/day for <5 years, 75 mg/day for 5-12 years. Oral: 0.5-1 mg/kg every 4-6 hours; maximum 100 mg/day. Not recommended for children <6 months due to increased risk of extrapyramidal reactions. |
| Geriatric use | Initiate at 10-25 mg orally or 12.5-25 mg intramuscularly/intravenously every 4-6 hours; increase cautiously. Monitor for orthostatic hypotension, sedation, and anticholinergic effects. Avoid use in dementia-related psychosis due to increased mortality risk. Use lowest effective dose for shortest duration. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for SPARINE (SPARINE).
| Breastfeeding | Sparine (promazine) is excreted in breast milk; M/P ratio not established. Risk of sedation and EPS in nursing infant. American Academy of Pediatrics recommends caution; avoid use during breastfeeding if possible, especially in preterm or jaundiced neonates. |
| Teratogenic Risk | FDA Pregnancy Category C. First trimester: limited human data; animal studies show embryotoxicity and delayed skeletal ossification at high doses. Second/third trimesters: risk of extrapyramidal symptoms (EPS) and withdrawal in neonates if used near term. No documented increase in major malformations. |
■ FDA Black Box Warning
Increased mortality in elderly patients with dementia-related psychosis; risk of QT prolongation and torsade de pointes with IV use.
| Serious Effects |
Comatose states, CNS depression from barbiturates or alcohol, bone marrow suppression, liver disease, severe hypotension, history of QT prolongation, hypersensitivity to phenothiazines.
| Precautions | Risk of tardive dyskinesia, neuroleptic malignant syndrome, hypotension, QT prolongation, seizures, anticholinergic effects, leukopenia, and phototoxicity. |
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| Fetal Monitoring |
| Monitor maternal blood pressure, heart rate, and ECG (QT prolongation risk). Fetal monitoring: assess for neonatal EPS, sedation, and withdrawal symptoms after delivery. In third trimester, monitor for gestational diabetes and weight gain. |
| Fertility Effects | May cause hyperprolactinemia leading to menstrual irregularities, galactorrhea, and transient infertility. In males, erectile dysfunction and decreased libido reported. Reversible upon discontinuation. |