Mivacron Dosage

Initial Doses

Doses of 0.15 mg/kg administered over 5 to 15 seconds, 0.2 mg/kg administered over 30 seconds, or 0.25 mg/kg administered in divided doses (0.15 mg/kg followed in 30 seconds by 0.1 mg/kg) are recommended for facilitation of tracheal intubation for most patients (see Table 7).

The purpose of slowed or divided dosing of MIVACRON at doses above 0.15 mg/kg is to minimize the transient decreases in blood pressure observed in some patients given these doses over 5 to 15 seconds (see CLINICAL PHARMACOLOGY, PRECAUTIONS, and ADVERSE REACTIONS). The quality of intubation conditions does not significantly differ for the times and doses of MIVACRON recommended in Table 7, but the onset of suitable intubation conditions may be reached earlier with higher doses. The choice of a particular dose and regimen should be based on individual circumstances and patient requirements (see CLINICAL PHARMACOLOGY - Individualization of Dosages).

In patients with clinically significant cardiovascular disease and in patients with any history suggesting a greater sensitivity to the release of histamine or other mediators (e.g., asthma), the dose of MIVACRON should be 0.15 mg/kg or less, administered over 60 seconds (see PRECAUTIONS). No data are available on the use of doses of MIVACRON above 0.15 mg/kg in patients with clinically significant kidney or liver disease.

Clinically effective neuromuscular block may be expected to last for 15 to 20 minutes (range: 9 to 38 minutes) and spontaneous recovery may be expected to be 95% complete in 25 to 30 minutes (range: 16 to 41 minutes) following 0.15 mg/kg MIVACRON administered to patients receiving opioid/nitrous oxide/oxygen anesthesia. The expected duration of clinically effective block and time to 95% spontaneous recovery following 0.2 mg/kg MIVACRON are approximately 20 and 30 minutes, respectively, and following 0.25 mg/kg MIVACRON are approximately 25 and 35 minutes. Initiation of maintenance dosing during opioid/nitrous oxide/oxygen anesthesia is generally required approximately 15, 20 and 25 minutes following initial doses of 0.15 mg/kg, 0.2 mg/kg, and 0.25 mg/kg MIVACRON, respectively (see Table 1). Maintenance doses of 0.1 mg/kg each provide approximately 15 minutes of additional clinically effective block. For shorter or longer durations of action, smaller or larger maintenance doses may be administered.

The neuromuscular blocking action of MIVACRON is potentiated by isoflurane or enflurane anesthesia. Recommended initial doses of MIVACRON may be used to facilitate tracheal intubation prior to the administration of these agents; however, if MIVACRON is first administered after establishment of stable-state isoflurane or enflurane anesthesia (administered with nitrous oxide/oxygen to achieve 1.25 MAC), the initial dose of MIVACRON may be reduced by as much as 25%. Greater reductions in the dose of MIVACRON may be required with higher concentrations of enflurane or isoflurane. With halothane, which has only a minimal potentiating effect on MIVACRON, a smaller dosage reduction may be considered.

Continuous Infusion

Continuous infusion of MIVACRON may be used to maintain neuromuscular block. Upon early evidence of spontaneous recovery from an initial dose, an initial infusion rate of 9 to 10 mcg/kg/min is recommended. If continuous infusion is initiated simultaneously with the administration of an initial dose, a lower initial infusion rate should be used (e.g., 4 mcg/kg/min). In either case, the initial infusion rate should be adjusted according to the response to peripheral nerve stimulation and to clinical criteria. On average, an infusion rate of 5 to 7 mcg/kg/min (range: 1 to 15 mcg/kg/min) may be expected to maintain neuromuscular block within the range of 89% to 99% for extended periods in adults receiving opioid/nitrous oxide/oxygen anesthesia. In some patients, particularly those with higher infusion requirements (greater than 8 mcg/kg/min) during the first 30 minutes, the infusion rate required to maintain 89% to 99% T1 suppression may decrease gradually (by greater than or equal to 30%) with time over a 4- to 6-hour period of infusion (see CLINICAL PHARMACOLOGY - Pharmacodynamics). Reduction of the infusion rate by up to 35% to 40% should be considered when MIVACRON is administered during stable-state conditions of isoflurane or enflurane anesthesia (administered with nitrous oxide/oxygen to achieve 1.25 MAC). Greater reductions in the infusion rate of MIVACRON may be required with greater concentrations of enflurane or isoflurane. With halothane, smaller reductions in infusion rate may be required.

Initial Doses

Dosage requirements for MIVACRON on a mg/kg basis are higher in children than in adults. Onset and recovery of neuromuscular block occur more rapidly in children than in adults (see CLINICAL PHARMACOLOGY).

The recommended dose of MIVACRON for facilitating tracheal intubation in children 2 to 12 years of age is 0.2 mg/kg administered over 5 to 15 seconds. When administered during stable opioid/nitrous oxide/oxygen anesthesia, 0.2 mg/kg of MIVACRON produces maximum neuromuscular block in an average of 1.9 minutes (range: 1.3 to 3.3 minutes) and clinically effective block for 10 minutes (range: 6 to 15 minutes). Maintenance doses are generally required more frequently in children than in adults. Administration of doses of MIVACRON above the recommended range (greater than 0.2 mg/kg) is associated with transient decreases in MAP in some children (see CLINICAL PHARMACOLOGY - Hemodynamics). MIVACRON has not been studied in pediatric patients below the age of 2 years.

Continuous Infusion

Children require higher infusion rates of MIVACRON than adults. During opioid/nitrous oxide/oxygen anesthesia, the infusion rate required to maintain 89% to 99% neuromuscular block averages 14 mcg/kg/min (range: 5 to 31 mcg/kg/min). The principles for infusion of MIVACRON in adults are also applicable to children (see above).

Y-site Administration

MIVACRON Injection may not be compatible with alkaline solutions having a pH greater than 8.5 (e.g., barbiturate solutions).

Studies have shown that MIVACRON Injection is compatible with:

• 5% Dextrose Injection, USP
• 0.9% Sodium Chloride Injection, USP
• 5% Dextrose and 0.9% Sodium Chloride Injection, USP
• Lactated Ringer's Injection, USP
• 5% Dextrose in Lactated Ringer's Injection
• Sufenta® (sufentanil citrate) Injection, diluted as directed
• Alfenta® (alfentanil hydrochloride) Injection, diluted as directed
• Sublimaze® (fentanyl citrate) Injection, diluted as directed
• Versed® (midazolam hydrochloride) Injection, diluted as directed
• Inapsine® (droperidol) Injection, diluted as directed

Compatibility studies with other parenteral products have not been conducted.

Dilution Stability

MIVACRON Injection diluted to 0.5 mg mivacurium per mL in 5% Dextrose Injection, USP, 5% Dextrose and 0.9% Sodium Chloride Injection, USP, 0.9% Sodium Chloride Injection, USP, Lactated Ringer's Injection, USP, or 5% Dextrose in Lactated Ringer's Injection is physically and chemically stable when stored in PVC (polyvinylchloride) bags at 5° to 25°C (41° to 77°F) for up to 24 hours. Aseptic techniques should be used to prepare the diluted product. Admixtures of MIVACRON should be prepared for single patient use only and used within 24 hours of preparation. The unused portion of diluted MIVACRON should be discarded after each case.

NOTE: Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration whenever solution and container permit. Solutions which are not clear and colorless should not be used.