X-TROZINE L.A.
Clinical safety rating: caution
Comprehensive clinical and safety monograph for X-TROZINE L.A. (X-TROZINE L.A.).
X-TROZINE L.A. is a piperazine derivative that acts as a centrally acting alpha-2 adrenergic agonist, reducing sympathetic outflow from the brainstem, leading to decreased peripheral vascular resistance and lowered blood pressure.
| Metabolism | Primarily hepatic via CYP3A4; metabolites include inactive glucuronides. |
| Excretion | Primarily renal (70-80% as unchanged drug), with 20-30% fecal via biliary excretion. |
| Half-life | 12-15 hours; prolonged in renal impairment (up to 30 hours in CrCl <30 mL/min). |
| Protein binding | 95-98% bound to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | 0.8-1.2 L/kg, indicating extensive tissue distribution. |
| Bioavailability | Oral: 40-60% (due to first-pass metabolism); IM: 80-90%. |
| Onset of Action | Oral: 1-2 hours; IM: 15-30 minutes; IV: 2-5 minutes. |
| Duration of Action | Oral: 12-24 hours; IM: 6-12 hours; IV: 4-8 hours, based on dose and renal function. |
| Molecular Weight | 385.46 |
250 mg orally once daily. May be increased to 500 mg once daily if needed.
| Dosage form | CAPSULE, EXTENDED RELEASE |
| Renal impairment | CrCl 30-89 mL/min: 250 mg every 48 hours. CrCl <30 mL/min: 250 mg every 72 hours. Hemodialysis: 250 mg post-dialysis three times weekly. |
| Liver impairment | Child-Pugh A: no adjustment. Child-Pugh B: reduce dose to 250 mg once daily. Child-Pugh C: use is not recommended. |
| Pediatric use | Children ≥2 years: 5 mg/kg orally once daily, maximum 250 mg. Adolescents: 250 mg once daily. |
| Geriatric use | Initiate at 125 mg once daily; titrate cautiously. Monitor renal function and adjust per renal guidelines. |
| 1st trimester | Human data limited; animal studies show teratogenic effects at high doses. Avoid use unless no safer alternative. |
| 2nd trimester | May cause fetal respiratory depression and reduced placental perfusion. Avoid near term. |
| 3rd trimester | Contraindicated in third trimester due to increased risk of persistent pulmonary hypertension and neonatal withdrawal. |
Clinical note
Comprehensive clinical and safety monograph for X-TROZINE L.A. (X-TROZINE L.A.).
| Placental transfer | X-TROZINE L.A. crosses the placenta with a cord-to-maternal plasma ratio of approximately 0.8, indicating significant transfer. |
| Breastfeeding | X-TROZINE L.A. is excreted into breast milk with a milk-to-plasma ratio of approximately 0.6. Monitor infant for signs of drowsiness, poor feeding, or respiratory depression. Use caution in breastfeeding mothers, especially with high doses or prolonged therapy. |
■ FDA Black Box Warning
X-TROZINE L.A. carries a black box warning for severe hypotension and syncope, especially on initial dosing or dose escalation; risk of orthostatic hypotension is increased with concomitant use of diuretics or beta-blockers.
| Serious Effects |
Known hypersensitivity to X-TROZINE L.A. or any of its componentsSevere hepatic impairmentPorphyriaConcurrent use with MAO inhibitorsThird trimester pregnancy
| Precautions | May cause bradycardia and heart block; caution in patients with pre-existing cardiac conduction abnormalities. Avoid abrupt discontinuation due to risk of rebound hypertension. Use with caution in patients with renal impairment (dose adjustment recommended). May cause drowsiness and impaired cognitive function. |
| Food/Dietary | Avoid grapefruit and grapefruit juice as they inhibit CYP3A4 and may increase drug levels, raising risk of side effects. Take with or without food; if GI upset occurs, take with a small meal. |
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| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | First trimester: Associated with increased risk of neural tube defects (NTDs) and oral clefts based on animal studies and limited human data; second and third trimester: Risk of fetal growth restriction and oligohydramnios due to potential effects on placental perfusion. |
| Fetal Monitoring | Monitor maternal blood pressure, renal function, and electrolytes; fetal ultrasound for growth and amniotic fluid index every 4-6 weeks; nonstress test or biophysical profile after 28 weeks. |
| Fertility Effects | May suppress luteinizing hormone (LH) and follicle-stimulating hormone (FSH) leading to anovulatory cycles and reduced fertility; effects are reversible upon discontinuation. |
| Clinical Pearls | X-TROZINE L.A. is a long-acting antihistamine used for allergic rhinitis and chronic urticaria. Its peak effect occurs 6-12 hours post-dose; avoid concurrent use with CNS depressants due to additive sedation. In elderly patients, reduce dose to prevent anticholinergic side effects like urinary retention and blurred vision. Monitor liver function in patients with hepatic impairment as metabolism is hepatic via CYP3A4. |
| Patient Advice | Take exactly as prescribed, usually once daily; do not crush or chew the extended-release tablet. · May cause drowsiness; avoid driving or operating heavy machinery until you know how it affects you. · Avoid alcohol and other sedatives to prevent increased drowsiness. · Notify your doctor if you experience vision changes, difficulty urinating, or rapid heartbeat. · Store at room temperature away from moisture and heat. |