What is the proper dilution method for tigecycline (Tygacil) for antibiotic therapy?

From the Guidelines

To dilute tigecycline for antibiotic therapy, first reconstitute the 50 mg vial with 5.3 mL of 0.9% sodium chloride or 5% dextrose solution to achieve a concentration of 10 mg/mL, as recommended by recent guidelines 1. The standard adult dosing is a 100 mg loading dose followed by 50 mg every 12 hours, with each dose administered over 30-60 minutes.

Key Considerations

• Gently swirl the vial until the powder dissolves completely; avoid shaking.
• Immediately withdraw the required dose and further dilute in 100 mL of 0.9% sodium chloride or 5% dextrose solution for intravenous infusion.
• The diluted solution should appear yellow to orange in color and should be used within 24 hours if stored at room temperature or within 48 hours if refrigerated.
• Tigecycline is a glycylcycline antibiotic that works by binding to the 30S ribosomal subunit, inhibiting bacterial protein synthesis.
• It's essential to monitor patients for infusion reactions and be aware that tigecycline should not be administered through the same intravenous line as other medications unless compatibility has been established.

Clinical Context

The provided guidelines 1 focus on the treatment of infections due to multidrug-resistant organisms, including the use of tigecycline for intra-abdominal infections due to VRE.

• The recommended treatment duration is based on the clinical response and the site of infection.
• Combination therapy with tigecycline and other antibiotics may be suggested in clinically unstable patients.

Evidence Quality

The recommendations are based on weak evidence (2D) due to the limited availability of high-quality studies on the use of tigecycline for these specific indications.

• However, the guidelines provide a consensus-based approach to treatment, taking into account the current knowledge and clinical experience.
• As new evidence emerges, the recommendations may be updated to reflect the latest findings.

From the FDA Drug Label

2.4 Preparation and Administration Each vial of tigecycline for injection should be reconstituted with 5.3 mL of 0. 9% Sodium Chloride Injection, USP, 5% Dextrose Injection, USP, or Lactated Ringer's Injection, USP to achieve a concentration of 10 mg/mL of tigecycline. (Note: Each vial contains a 6% overage. Thus, 5 mL of reconstituted solution is equivalent to 50 mg of the drug.) The vial should be gently swirled until the drug dissolves. Reconstituted solution must be transferred and further diluted for intravenous infusion. Withdraw 5 mL of the reconstituted solution from the vial and add to a 100 mL intravenous bag for infusion (for a 100 mg dose, reconstitute two vials; for a 50 mg dose, reconstitute one vial) The maximum concentration in the intravenous bag should be 1 mg/mL.

The proper dilution method for tigecycline (Tygacil) for antibiotic therapy is to reconstitute each vial with 5.3 mL of 0.9% Sodium Chloride Injection, USP, 5% Dextrose Injection, USP, or Lactated Ringer's Injection, USP to achieve a concentration of 10 mg/mL of tigecycline, and then further dilute the reconstituted solution in a 100 mL intravenous bag to a maximum concentration of 1 mg/mL. 2

From the Research

Preparation and Administration of Tigecycline

• Tigecycline is administered intravenously, with a recommended dosage regimen of 100 mg initially, followed by 50 mg every 12 hours for 5-14 days 3.
• The drug is available as a lyophilized powder for injection, which must be reconstituted and diluted before administration.
• Tigecycline can be diluted in 0.9% sodium chloride solution or 5% glucose solution to obtain a concentration of 0.5 mg/ml 4.

Compatibility with Other Solutions

• Tigecycline has been shown to be physically compatible with selected multichamber bag parenteral nutrition (MCB-PN) solutions, allowing for co-administration through the same infusion line 4.
• The compatibility of tigecycline with other solutions should be evaluated on a case-by-case basis to ensure safety and efficacy.

Analytical Methods for Tigecycline

• Various analytical methods have been developed for the quantification and characterization of tigecycline, including UV-visible spectrophotometry, spectrofluorimetric methods, RP-HPLC, and FT-IR 5, 6.
• These methods can be used to evaluate the quality and stability of tigecycline in pharmaceutical products and clinical samples.

Antibiotic Activity and Resistance

• Tigecycline has been shown to exhibit broad-spectrum antibiotic activity against a range of clinical pathogens, including Gram-positive and Gram-negative bacteria 3, 7.
• The drug has been found to be effective against certain antibiotic-resistant organisms, making it a valuable treatment option for complicated skin and skin structure infections and intra-abdominal infections 3, 7.