HYLOREL
Clinical safety rating: caution
Comprehensive clinical and safety monograph for HYLOREL (HYLOREL).
Selective alpha-1 adrenergic receptor antagonist; inhibits sympathetic vasoconstriction, reducing peripheral vascular resistance and blood pressure.
| Metabolism | Extensively metabolized in the liver via O-demethylation and conjugation; CYP450 enzymes involved (CYP2D6, CYP3A4). |
| Excretion | Primarily renal (50-60% unchanged) and biliary/fecal (40-50%). |
| Half-life | Approximately 12-15 hours; clinically, steady-state achieved in 2-3 days. |
| Protein binding | 90-95% bound to plasma proteins (albumin and alpha-1-acid glycoprotein). |
| Volume of Distribution | 0.5-0.7 L/kg; indicates distribution into total body water. |
| Bioavailability | 85-90% after oral administration. |
| Onset of Action | 2-4 hours after oral dosing. |
| Duration of Action | 24-48 hours; may require dose adjustment in renal impairment. |
10 mg orally twice daily, titrated to 20-40 mg twice daily based on blood pressure response.
| Dosage form | TABLET |
| Renal impairment | No adjustment needed for mild to moderate renal impairment (GFR 30-89 mL/min). For severe renal impairment (GFR <30 mL/min), reduce dose by 50% and monitor blood pressure closely. |
| Liver impairment | For Child-Pugh Class A: no adjustment. For Class B: reduce starting dose to 5 mg twice daily, titrate cautiously. For Class C: avoid use due to lack of safety data. |
| Pediatric use | Not recommended in pediatric patients due to lack of safety and efficacy data. |
| Geriatric use | Start at 5 mg twice daily, titrate slowly; monitor for orthostatic hypotension and electrolyte imbalances due to age-related changes in renal function and sympathetic response. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for HYLOREL (HYLOREL).
| Breastfeeding | Excreted in human milk in small amounts; M/P ratio unknown. Use caution in nursing mothers, especially in preterm neonates due to potential for hypotension and bradycardia. Monitor infant for sedation, poor feeding, and hypotonia. |
| Teratogenic Risk | Pregnancy Category C. First trimester: No adequate studies, but potential for fetal harm based on animal data (skeletal abnormalities, reduced fetal weight at high doses). Second and third trimesters: May cause fetal bradycardia, hypotension, and reduced placental perfusion; avoid use due to risk of oligohydramnios and fetal renal impairment. |
■ FDA Black Box Warning
None
| Common Effects | Limited data available |
| Serious Effects |
["Hypersensitivity to guanadrel or similar drugs","Concomitant use with MAO inhibitors"]
| Precautions | ["Syncope and orthostatic hypotension","Priapism","Intraoperative floppy iris syndrome","Use in patients with impaired hepatic function"] |
Loading safety data…
| Fetal Monitoring | Maternal: Blood pressure, heart rate, signs of hypotension (dizziness, syncope), fluid status. Fetal: Ultrasound for amniotic fluid index if used in second/third trimester; fetal heart rate monitoring. Neonatal: Apgar scores, blood pressure, and heart rate for 24-48 hours postpartum if exposed near term. |
| Fertility Effects | Reproductive toxicity studies in animals showed no impairment of fertility at therapeutic doses. In humans, no specific studies; however, alpha2-agonists may theoretically affect libido or erectile function but no conclusive evidence of fertility impairment. |