Dosing and uses of Trandate (labetalol)
Adult dosage forms and strengths
injectable solution
- 5mg/mL
tablet
- 100mg
- 200mg
- 300mg
Hypertension
100 mg PO q12hr initially; increased by 100 mg q12hr every 2-3 days
Usual dosage range: 200-400 mg PO q12hr; not to exceed 2400 mg/day
Hypertensive Emergency
20 mg IV over 2 minutes initially, then 40-80 mg IV q10min; total dose not to exceed 300 mg
Alternative: 1-2 mg/min by continuous IV infusion; total dose of 300 mg has been used
Dosing Modifications
Renal impairment: Not studied; no supplement needed after dialysis
Hepatic impairment: Not studied; dosage reduction may be necessary
Dosing Considerations
Monitor blood pressure every 5-10 minutes
Pediatric dosage forms and strengths
injectable solution
- 5mg/mL
tablet
- 100mg
- 200mg
- 300mg
Hypertensive Emergency
0.4-1 mg/kg/hr by continuous IV infusion; not to exceed 3 mg/kg/hr
Hypertension (Off-label)
1-3 mg/kg/day PO divided q12hr; not to exceed 1200 mg/day
Alternative: 0.3-1 mg/kg intermittent IV bolus
Trandate (labetalol) adverse (side) effects
>10%
Dizziness (1-20%)
Lightheadedness (1-20%)
Nausea (≤19%)
Tingling sensation of scalp (4-12%)
Fatigue (1-11%)
1-10%
Elevated serum blood urea nitrogen (BUN) (≤8%)
Elevated serum creatinine (8%)
Congestion of nasal sinus (1-6%)
Orthostatic hypotension (1-5%)
Absence of ejaculation (<5%)
Paresthesia (<5%)
Elevated liver enzymes (4%)
Diaphoresis (≤4%)
Edema (≤2%)
Bronchospasm (1-2%)
Dyspnea (1-2%)
Pruritus (1%)
Rash (1%)
Altered taste sense (1%)
Ventricular arrhythmia (1%; IV)
Frequency not defined
Angioedema
Bradycardia
Alopecia
Cholestatic jaundice
Depression
Diabetes insipidus
Hepatitis
Raynaud syndrome
Toxic myopathy
Urinary retention
Urticaria
Raynaud phenomenon
Warnings
Contraindications
Asthma or obstructive airway disease, severe bradycardia, 2°/3° heart block (without pacemaker), cardiogenic shock, bronchial asthma, uncompensated cardiac failure, hypersensitivity, sinus bradycardia, sick sinus syndrome without permanent pacemaker; conditions associated with prolonged and severe hypotension
Cautions
Use with caution in anesthesia or surgery (myocardial depression), bronchospastic disease (not recommended), cerebrovascular insufficiency, diabetes mellitus, hyperthyroidism or thyrotoxicosis, hepatic impairment, renal impairment, peripheral vascular disease, compromised left ventricular function, advanced age, heart failure, pheochromocytoma
Increased risk of stroke after surgery
Severe hepatic injury reported with use; with prolonged use, monitor liver function tests
Sudden discontinuance can exacerbate angina and lead to myocardial infarction
Use with caution in patients taking calcium channel blockers, cardiac glycosides, or inhaled anesthetics
Intraoperative floppy iris syndrome observed during cataract surgery in some patients treated with alpha1 blockers (labetalol is both an alpha and a beta blocker)
Hypotension with or without syncope may occur; monitor
Consider pre-existing conditions, such as, sick sinus syndrome before initiating therapy
Use caution in patients with history of severe anaphylaxis to allergens; patients taking beta-blockers may become more sensitive to repeated challenges; treatment with epinephrine in patients taking beta-blockers may be ineffective or promote undesirable effects
Use with caution in patients with myasthenia gravis, psoriasis, or psychiatric illness (may cause or exacerbate CNS depression)
Pregnancy and lactation
Pregnancy category: C
Lactation: Small amounts excreted; use with caution
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Trandate (labetalol)
Mechanism of action
Nonselective beta blocker with intrinsic sympathomimetic activity; also alpha blocker
Absorption
Bioavailability: 25% (PO)
Onset: PO, 20-120 min; IV, 2.5 min
Duration: 100 mg, 8 hr; 300 mg, 12 hr
Peak plasma time: 1-2 hr (PO)
Peak effect: 15 min (IV); 1-4 hr (PO)
Distribution
Protein bound: 50%
Vd: 3-16 L/kg (adults)
Metabolism
Metabolized mainly through conjugation to glucuronide metabolites
Elimination
Half-life: 6-8 hr (PO); 5.5 hr (IV)
Excretion: Urine (55-60%), feces via bile
Administration
IV Compatibilities
Solution: Compatible with most common solvents
Y-site: Alcohol 10% in D5W, amikacin, aminophylline, amiodarone, ampicillin, bivalirudin, butorphanol, calcium gluconate, cefazolin, ceftazidime, ceftizoxime, chloramphenicol, cimetidine, clindamycin, dexmedetomidine, diltiazem, dobutamine, dopamine, enalaprilat, epinephrine, erythromycin, esmolol, famotidine, fenoldopam, fentanyl, gatifloxacin, gentamicin, heparin (incompatible at 5 mg/mL), hetastarch, hydromorphone, insulin (?), lidocaine, linezolid, lorazepam, magnesium sulfate, meperidine, metronidazole, midazolam, milrinone, morphine, nicardipine, nitroglycerin, norepinephrine, oxacillin, penicillin G, piperacillin, potassium chloride, potassium phosphates, propofol, ranitidine, sodium acetate, sodium nitroprusside, tobramycin, trimethoprim-sulfamethoxazole, vancomycin, vecuronium
IV Incompatibilities
Solution: Sodium bicarbonate 5%
Y-site: Amphotericin B cholesteryl sulfate, cefoperazone, ceftriaxone, furosemide, nafcillin, thiopental, warfarin
IV Preparation
Standard diluent: 500 mg/250 mL D5W
Minimum volume: 250 mL D5W
IV Administration
Requires infusion pump
Slow direct IV push administered over 2 minutes
Loading infusions (2 mg/min) require close monitoring of HR and BP and are terminated after response occurs or a cumulative dose of 300 mg is reached
Continuous infusions of 2-6 mg/hr have been used in some settings and should not be confused with loading infusions
Storage
Store at room temperature or under refrigeration (2-30°C [36-86°F])
Protect from light and freezing
Solution is clear to slightly yellow
