Before taking any medication, it is essential to consult with a healthcare provider. The information provided here is for general knowledge and should not be taken as medical advice.
Tesamorelin, sold under brand names like Egrifta SV and Egrifta WR, is a medication prescribed to help reduce excess abdominal fat associated with HIV-associated lipodystrophy. It is delivered as an injection, and before it can be administered, the lyophilized (freeze-dried) powder must be carefully mixed with a liquid, a process known as reconstitution. The amount and type of liquid—or diluent—required differ significantly between the Egrifta SV and Egrifta WR formulations. To ensure safety and efficacy, patients and caregivers must understand these specific reconstitution instructions and use only the diluent provided with the medication kit.
Why Different Formulations Require Different Amounts of Water
The reason for the varied reconstitution instructions lies in the different properties of the Egrifta SV and Egrifta WR formulations. While both contain tesamorelin, they are not interchangeable and have distinct preparation and storage needs. The manufacturer's instructions are tailored to create a specific concentration for each product, which in turn determines the volume of the final preparation. Any deviation from these instructions can alter the concentration of the medication.
Key differences between the two formulations include:
- Diluent Type: Egrifta SV uses Sterile Water for Injection, while Egrifta WR uses Bacteriostatic Water for Injection, which contains a preservative allowing for multi-day use after mixing.
- Reconstitution Frequency: Egrifta SV must be mixed daily just before each injection. Egrifta WR is mixed only once per week and can be stored at room temperature for up to 7 days after reconstitution.
- Packaging: The diluent, syringes, and other supplies are packaged specifically for each product, and components should not be swapped between kits.
Step-by-Step Instructions for Reconstituting Tesamorelin
For EGRIFTA SV (2 mg vial):
- Gather Supplies: Ensure you have the EGRIFTA SV vial, the 10 mL bottle of Sterile Water for Injection, the syringe, and needles from the kit.
- Add Diluent: Follow the specific volume indicated in the instructions for use for Sterile Water for Injection using the syringe. Inject the water slowly down the inside wall of the vial to avoid foaming.
- Mix Gently: Roll the vial gently between your hands for 30 seconds to mix the powder and diluent. Do not shake.
- Inspect the Solution: Check that the solution is clear, colorless, and free of particulate matter. Do not use if it is cloudy or contains solid particles.
- Prepare the Injection: Follow the instructions for the volume of the reconstituted solution to withdraw for injection immediately. Discard any unused solution and diluent, as this is a single-use preparation.
For EGRIFTA WR (11.6 mg vial):
- Gather Supplies: Use only the provided Bacteriostatic Water for Injection and equipment from the EGRIFTA WR kit.
- Add Diluent: Follow the specific volume indicated in the instructions for use for Bacteriostatic Water for Injection and inject it slowly into the vial to prevent foaming.
- Mix Gently: Swirl the vial gently to mix. Do not shake.
- Inspect the Solution: Ensure the solution is clear and colorless before using.
- Prepare the Injection: After mixing for the first time, the vial can be used for 7 consecutive daily injections. Follow the instructions for the volume of the reconstituted solution to withdraw for each daily injection.
Comparison of Tesamorelin Formulations
| Feature | Egrifta SV (2 mg/vial) | Egrifta WR (11.6 mg/vial) |
|---|---|---|
| Diluent Type | Sterile Water for Injection, USP | Bacteriostatic Water for Injection, USP |
| Reconstitution Volume | Specific volume per vial | Specific volume per vial |
| Preparation Frequency | Daily, immediately before injection | Weekly, used for 7 consecutive days |
| Volume for Injection | Specific volume of reconstituted solution | Specific volume of reconstituted solution |
| Reconstituted Vial Storage | Discard immediately | Up to 7 days at room temperature (protected from light) |
| Reconstituted Vial Freezing | Not permitted | Not permitted |
The Importance of Correct Dilution
Correct dilution is more than a procedural step; it is integral to the medication's pharmacological action. Tesamorelin is a peptide that can be easily denatured or rendered ineffective by improper handling, such as shaking vigorously during reconstitution. The correct volume of diluent ensures the final solution has the proper concentration, and administering the correct volume of that solution guarantees the patient receives the intended dose. Using an incorrect diluent or volume can impact the drug's stability and bioavailability. It is essential for patients and caregivers to consult the detailed "Instructions for Use" provided by the manufacturer with every medication box.
Conclusion
The question of how much water to use for tesamorelin depends entirely on the product version: Egrifta SV or Egrifta WR. For Egrifta SV, use the specific volume of Sterile Water for Injection indicated in the instructions for use and prepare the dose daily. For Egrifta WR, use the specific volume of Bacteriostatic Water for Injection indicated in the instructions for use once weekly. Always use the specific diluent provided in the kit and follow reconstitution instructions carefully. Never substitute diluents, and never reuse syringes or needles. For any questions or concerns regarding proper preparation, always consult with a healthcare professional or pharmacist. Adherence to these specific instructions is paramount for the safe and effective use of tesamorelin.
