Trepar Dosage/Direction for Use

Dactinomycin is toxic and the severity of toxicity is dependent on the dosage employed. Therefore, the drug must be given in short courses.
Intravenous Use: The dosage of Dactinomycin varies depending on the tolerance of the patient, the size and location of the neoplasm and the use of other forms of therapy. It may be necessary to decrease the usual dosages suggested below when other chemotherapy or x-ray therapy is used concomitantly or has been used previously.
The dosage for adults or children should not exceed 15 μg (potency)/kg or 0.4-0.6 mg (potency)/m² of body surface daily intravenously for five days. Calculation of the dosage for obese or edematous patients should be on the basis of surface area in an effect to relate dosage to lean body mass.
Adults: The usual adult dosage is 0.5 mg (potency) daily intravenously for a maximum of five days.
Children: In children 15 μg (potency) per kg of body weight is given intravenously daily for five days. An alternative schedule is a total dosage of 2.5 mg (potency) per m² of body surface given intravenously over a one-week period.
In both adults and children, a second course may be given after at least three weeks have lapsed, provided all signs of toxicity have disappeared.
Reconstitution: Reconstitute Dactinomycin by adding 1.1 mL of Sterile Water for Injection (without preservative) under aseptic conditions. The resulting solution of Dactinomycin will contain approximately 0.5 mg/mL.
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit (When reconstituted, Dactinomycin is a clear, gold-colored solution).
Once reconstituted, the solution of Dactinomycin can be added to infusion solutions of 5% Dextrose Injection or Sodium Chloride Injection either directly or to the tubing of a running intravenous infusion.
Although reconstituted, Dactinomycin is chemically stable. The product does not contain a preservative, and thus, care must be taken to assure the sterility of prepared solutions. Any unused portion should be discarded. Use of water which contains any preservative (benzyl alcohol or parabens) to reconstitute Dactinomycin for Injection results in the formation of a precipitate.
Partial removal of Dactinomycin from intravenous solutions by cellulose ester membrane filters used in some intravenous in-line filters has been reported.
If the drug is given directly into the vein without the use of an infusion, the "two-needle technique" should be used. Reconstitute and withdraw the calculated dose from the vial with one sterile needle. Use another sterile needle for direct injection into the vein. Discard any unused portion of the Dactinomycin solution.
The reconstituted solution is stable at room temperature; however, this solution contains no preservative so it has been suggested that unused portions of the injection be discarded.
Isolation-Perfusion Technique: The dosage schedules and the technique itself are as follows: 50 μg (potency) per kg of body weight for lower extremity or pelvis.
35 μg (potency) per kg of body weight for upper extremity.
It may be advisable to use lower doses in obese patients, or when previous chemotherapy or radiation therapy has been employed.
Complications of the perfusion technique are related mainly to the amount of drug that escapes into the systemic circulation and may consist of hemopoietic depression, absorption of toxic products from massive destruction of neoplastic tissue, increased susceptibility to infection, impaired wound healing, and superficial ulceration of the gastric mucosa. Other side effects may include edema of the extremity involved, damage to soft tissues of the perfused area, and (potentially) venous thrombosis.