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 |
| Molecular Weight | 462.58 |
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 | Avoid due to potential teratogenicity; limited human data but animal studies suggest risk. |
| 2nd trimester | Use only if clearly needed; may cause maternal hypotension and fetal hypoxia. |
| 3rd trimester | Avoid near term; risk of neonatal respiratory depression, extrapyramidal signs, and prolonged QT interval. |
Clinical note
Comprehensive clinical and safety monograph for SPARINE (SPARINE).
| Placental transfer | Crosses placenta; documented in human studies. |
| Breastfeeding | Interindividual variability; small amounts excreted into breastmilk. Monitor infant for sedation, poor feeding, and extrapyramidal symptoms. |
| Lactation Rating |
■ 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 |
Hypersensitivity to promazine or any phenothiazineSevere CNS depressionComatose statesConcurrent use of high-dose CNS depressantsBone marrow suppressionPheochromocytoma
| Precautions | Risk of tardive dyskinesia, neuroleptic malignant syndrome, hypotension, QT prolongation, seizures, anticholinergic effects, leukopenia, and phototoxicity. |
| Food/Dietary | Avoid alcohol and products containing alcohol (e.g., some mouthwashes, cough syrups) due to additive CNS depression. Grapefruit juice may increase the risk of QT prolongation by inhibiting CYP3A4 metabolism of promazine; limit or avoid grapefruit products. Caffeine-containing beverages may exacerbate anxiety or insomnia. |
Loading safety data…
| L3 - Moderately Safe |
| 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. |
| 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. |
| Clinical Pearls | SPARINE (promazine) is a phenothiazine antipsychotic with strong anticholinergic effects; use with caution in elderly due to risk of sedation and falls. Monitor for QT prolongation, especially in patients with electrolyte imbalances or concurrent use of QT-prolonging drugs. Extrapyramidal symptoms (EPS) are less common than with high-potency agents but may occur. Avoid in patients with narrow-angle glaucoma, prostate hypertrophy, or seizure disorders. Taper gradually to avoid withdrawal dyskinesia. |
| Patient Advice | Take exactly as prescribed; do not stop abruptly without consulting your healthcare provider. · Do not drink alcohol or use other central nervous system depressants while taking SPARINE. · Avoid activities requiring mental alertness, such as driving, until you know how this medicine affects you. · Report any muscle stiffness, tremors, restlessness, or unusual movements to your doctor promptly. · Rise slowly from sitting or lying positions to minimize dizziness and fainting. · Protect your skin from sun exposure; use sunscreen and wear protective clothing as SPARINE may increase sensitivity to sunlight. · Store at room temperature away from moisture and heat. |