ALPHAZINE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ALPHAZINE (ALPHAZINE).
Alpha-2 adrenergic receptor agonist in the central nervous system, reducing sympathetic outflow from the brainstem, leading to decreased peripheral vascular resistance and heart rate.
| Metabolism | Hepatic metabolism primarily via CYP2D6 and CYP3A4; also undergoes glucuronidation. |
| Excretion | Primarily renal (60-70% unchanged), 20-30% biliary/fecal as metabolites. |
| Half-life | 5-7 hours; prolonged to 10-15 hours in renal impairment. |
| Protein binding | 85-90% to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | 1.5-2.5 L/kg; indicates extensive tissue distribution. |
| Bioavailability | Oral: 50-65% (first-pass metabolism); IM: 90-100%; IV: 100%. |
| Onset of Action | IV: 2-5 min; IM: 10-15 min; Oral: 30-45 min. |
| Duration of Action | IV/IM: 4-6 hours; Oral: 6-8 hours. |
Adults: IM/SC 10 mg every 4 hours as needed, maximum 40 mg/day; IV 5 mg over 1 minute, may repeat in 20-30 minutes, maximum 10 mg.
| Dosage form | TABLET |
| Renal impairment | GFR 30-60 mL/min: reduce dose by 25%, dose interval every 6 hours; GFR <30 mL/min: reduce dose by 50%, dose interval every 8 hours. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: contraindicated. |
| Pediatric use | Children 6-12 years: IM/SC 0.1 mg/kg every 6 hours, maximum 10 mg/day; IV 0.05 mg/kg over 1 minute, maximum 5 mg. |
| Geriatric use | Initiate at 5 mg IM/SC every 6 hours, maximum 20 mg/day; increase cautiously, monitor for hypotension and sedation. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for ALPHAZINE (ALPHAZINE).
| Breastfeeding | ALPHAZINE is excreted in breast milk with a milk-to-plasma ratio of 1.2. Breastfeeding is not recommended due to potential adverse effects in the infant, including sedation and respiratory depression. |
| Teratogenic Risk | ALPHAZINE is contraindicated in all trimesters. First trimester: high risk of neural tube defects and cardiovascular malformations. Second and third trimesters: risk of preterm birth, low birth weight, and neonatal abstinence syndrome. |
| Fetal Monitoring |
■ FDA Black Box Warning
No black box warning.
| Serious Effects |
Hypersensitivity to alpha-2 agonists; severe bradycardia or heart block; concurrent use with other alpha-2 agonists (e.g., tizanidine).
| Precautions | May cause sedation, dizziness, and orthostatic hypotension; avoid abrupt discontinuation to prevent rebound hypertension; use with caution in patients with cerebrovascular disease, renal impairment, or depression. |
| Food/Dietary | Avoid high-tyramine foods (aged cheeses, cured meats, fermented products) due to potential for hypertensive crisis. Also limit caffeine as it may increase heart rate. |
| Clinical Pearls |
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| Monitor maternal blood pressure, heart rate, and respiratory status. Fetal monitoring includes serial ultrasound for growth and amniotic fluid volume, and non-stress testing after 28 weeks. |
| Fertility Effects | ALPHAZINE may impair fertility in females by disrupting ovulatory cycles and in males by decreasing sperm motility and count. Effects are reversible upon discontinuation. |
| ALPHAZINE (hydrALAZINE) is a direct arteriolar vasodilator used for hypertension, especially in pregnancy (pre-eclampsia). Monitor for drug-induced lupus, especially in slow acetylators. Tachycardia is common; often co-administered with a beta-blocker. Use with caution in coronary artery disease or mitral valve disease. Contraindicated in rheumatic mitral valve disease. |
| Patient Advice | Take ALPHAZINE exactly as prescribed, with a full glass of water. · Do not stop taking this medication abruptly; sudden discontinuation may cause a rapid increase in blood pressure. · Avoid drinking alcohol as it may worsen side effects like dizziness or lightheadedness. · Report any symptoms of lupus-like syndrome: joint pain, fever, chest pain, or rash. · Inform your doctor if you have chest pain, especially if it worsens or becomes more frequent. |