DOSAGE AND ADMINISTRATION
Vitrase (hyaluronidase for injection) should be administered only as discussed below, since its effects relative to absorption and dispersion of other drugs are not produced when it is administered intravenously.
Vitrase is to be reconstituted in the vial to a concentration of 1000 Units/mL of Sodium Chloride Injection, USP by adding 6.2 mL of solution to the vial. Prior to administration, the reconstituted solution should be further diluted to the desired concentration, commonly 150 Units/mL, see table below. The resulting solution should be used immediately after preparation.
A 1mL syringe and a 5-micron filter needle are supplied in the Vitrase kit. Following reconstitution of Vitrase, as described above, apply the 5-micron filter needle to the 1mL syringe. Draw the desired amount of Vitrase into the syringe, and dilute according to the table below. Remove the filter needle and apply a needle appropriate for the intended injection.
| Desired Concentration | Amount of hyaluronidase reconstituted solution
(1000 Units/mL) | Additional Saline
Chloride Injection |
| 50 Units/mL | 0.05 mL | 0.95 mL |
| 75 Units/mL | 0.075 mL | 0.925 mL |
| 150 Units/mL | 0.15 mL | 0.85 mL |
| 300 Units/mL | 0.3 mL | 0.7 mL |
Absorption and Dispersion of Injected Drugs
Absorption and dispersion of other injected drugs may be enhanced by adding 50-300 Units, most typically 150 Units of hyaluronidase to the injection solution.
It is recommended that appropriate references be consulted regarding physical or chemical incompatibilities before adding Vitrase to a solution containing another drug.
Hypodermoclysis
Insert needle with aseptic precautions. With tip lying free and movable between skin and muscle, begin clysis; fluid should start in readily without pain or lump. Then inject Vitrase (hyaluronidase for injection) into rubber tubing close to needle.
An alternate method is to inject Vitrase under skin prior to clysis. 150 Units will facilitate absorption of 1,000 mL or more of solution. As with all parenteral fluid therapy, observe effect closely, with same precautions for restoring fluid and electrolyte balance as in intravenous injections. The dose, the rate of injection, and the type of solution (saline, glucose, Ringer’s, etc.) must be adjusted carefully to the individual patient. When solutions devoid of inorganic electrolytes are given by hypodermoclysis, hypovolemia may occur. This may be prevented by using solutions containing adequate amounts of inorganic electrolytes and/or controlling the volume and speed of administration.
Vitrase may be added to small volumes of solution (up to 200 mL), such as small clysis for infants or solutions of drugs for subcutaneous injection. For infants and children less than 3 years old, the volume of a single clysis should be limited to 200 mL; and in premature infants or during the neonatal period, the daily dosage should not exceed 25 mL/kg of body weight; the rate of administration should not be greater than 2 mL per minute. For older patients, the rate and volume of administration should not exceed those employed for intravenous infusion.
Subcutaneous Urography
The subcutaneous route of administration of urographic contrast media is indicated when intravenous administration cannot be successfully accomplished, particularly in infants and small children. With the patient prone, 75 Units of Vitrase (hyaluronidase for injection) is injected subcutaneously over each scapula, followed by injection of the contrast medium at the same sites.
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.
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