From the Guidelines
Labetalol infusion should be administered at a dose of 0.25–0.5 mg/kg i.v. bolus, followed by a continuous infusion of 2–4 mg/min until the goal blood pressure is reached, and thereafter 5–20 mg/h, as recommended by the most recent guidelines 1. The preparation of labetalol infusion typically involves creating a dilution of 1 mg/mL or 2 mg/mL concentration.
- The standard preparation involves adding 200 mg of labetalol to 160 mL of compatible IV fluid (such as D5W or normal saline) to create a 1 mg/mL solution, or adding 200 mg to 80 mL of IV fluid for a 2 mg/mL concentration.
- For administration, the initial infusion rate is usually based on the patient's weight and blood pressure response, with close monitoring of blood pressure and heart rate during administration.
- The diluted solution should be used within 24 hours, and the infusion should be administered via an infusion pump for precise control.
- Labetalol works by blocking both alpha and beta adrenergic receptors, providing rapid blood pressure reduction while maintaining cardiac output, making it particularly useful for hypertensive emergencies, as outlined in the European Heart Journal 1. Key considerations for labetalol infusion include:
- Contraindications such as history of 2nd or 3rd degree AV block, systolic heart failure, asthma, and bradycardia.
- Potential adverse effects like bronchoconstriction and fetal bradycardia.
- The need for close monitoring of blood pressure and heart rate during administration, with vital signs typically checked every 5-15 minutes initially.
From the FDA Drug Label
Labetalol HCl Injection is prepared for continuous intravenous infusion by diluting the vial contents with commonly used intravenous fluids (see below) Examples of two methods of preparing the infusion solution are: The contents of either two 20-mL vials (40 mL), or one 40-mL vial, are added to 160 mL of a commonly used intravenous fluid such that the resultant 200 mL of solution contains 200 mg of labetalol HCl, 1 mg/mL. Alternatively, the contents of either two 20-mL vials (40 mL), or one 40-mL vial, of labetalol HCl injection are added to 250 mL of a commonly used intravenous fluid. The resultant solution will contain 200 mg of labetalol HCl, approximately 2 mg/3 mL.
The dilution for Labetalol infusion can be either:
- 200 mg of labetalol HCl in 200 mL of solution, which is 1 mg/mL 2
- 200 mg of labetalol HCl in 250 mL of solution, which is approximately 2 mg/3 mL or 0.67 mg/mL 2
From the Research
Labetalol Infusion Dilution
- The provided studies do not directly mention the dilution for Labetalol infusion 3, 4, 5, 6, 7.
- However, it is known that Labetalol is often administered as an intravenous infusion for the management of hypertension, particularly in acute settings such as stroke or preeclampsia 6, 7.
- The studies focus on the comparison of Labetalol with other antihypertensive agents, its pharmacokinetics, and its efficacy in various clinical scenarios, but do not provide specific guidance on the dilution of Labetalol for infusion purposes.
- In clinical practice, the dilution of Labetalol for infusion is typically guided by hospital protocols or manufacturer recommendations, which may vary depending on the specific product and clinical context.