Overview
DESCRIPTION Thiotepa for Injection, USP is an ethylenimine-type compound. It is supplied as a non-pyrogenic, sterile Iyophilized powder for intravenous, intracavitary or intravesical administration, containing 15 mg of thiotepa. Thiotepa for injection is a synthetic product with antitumor activity.
Mechanism of Action
CLINICAL PHARMACOLOGY Thiotepa is a cytotoxic agent of the polyfunctional type, related chemically and pharmacologically to nitrogen mustard. The radiomimetic action of thiotepa is believed to occur through the release of ethylenimine radicals which, like irradiation, disrupt the bonds of DNA. One of the principal bond disruptions is initiated by alkylation of guanine at the N-7 position, which severs the linkage between the purine base and the sugar and liberates alkylated guanines. The pharmacokinetics of thiotepa and TEPA in thirteen female patients (45 to 84 years) with advanced stage ovarian cancer receiving 60 mg and 80 mg thiotepa by intravenous infusion on subsequent courses given at 4 week intervals are presented in the following table: Pharmacokinetic Parameters (units) Mean ±...
Indications
- INDICATIONS AND USAGE Thiotepa for Injection, USP has been tried with varying results in the palliation of a wide variety of neoplastic diseases. However, the most consistent results have been seen in the following tumors: 1. Adenocarcinoma of the breast. 2. Adenocarcinoma of the ovary. 3. For controlling intracavitary effusions secondary to diffuse or localized neoplastic diseases of various serosal cavities. 4. For the treatment of superficial papillary carcinoma of the urinary bladder.
Common Doses
- 10 mg
- 0.4 mg
- 0.8 mg
- 60 mg
Dosage
DOSAGE AND ADMINISTRATION Since absorption from the gastrointestinal tract is variable, thiotepa should not be administered orally. Dosage must be carefully individualized. A slow response to thiotepa does not necessarily indicate a lack of effect. Therefore, increasing the frequency of dosing may only increase toxicity. After maximum benefit is obtained by initial therapy, it is necessary to continue the patient on maintenance therapy (1 to 4 week intervals).
Contraindications
- CONTRAINDICATIONS Thiotepa is contraindicated in patients with a known hypersensitivity (allergy) to this preparation. Therapy is probably contraindicated in cases of existing hepatic, renal, or bone-marrow damage. However, if the need outweighs the risk in such patients, thiotepa may be used in low dosage, and accompanied by hepatic, renal and hemopoietic function tests.
Side Effects
- ADVERSE REACTIONS In addition to its effect on the blood-forming elements (see WARNINGS and PRECAUTIONS sections), thiotepa may cause other adverse reactions. General: Fatigue, weakness. Febrile reaction and discharge from a subcutaneous lesion may occur as the result of breakdown of tumor tissue. Hypersensitivity Reactions: Allergic reactions - rash, urticaria, laryngeal edema, asthma, anaphylactic shock, wheezing. Local Reactions: Contact dermatitis, pain at the injection site. Gastrointestinal: Nausea, vomiting, abdominal pain, anorexia. Renal: Dysuria, urinary retention.
Interactions
- Drug Interactions It is not advisable to combine, simultaneously or sequentially, cancer chemotherapeutic agents or a cancer chemotherapeutic agent and a therapeutic modality having the same mechanism of action. Therefore, thiotepa combined with other alkylating agents such as nitrogen mustard or cyclophosphamide or thiotepa combined with irradiation would serve to intensify toxicity rather than to enhance therapeutic response.