e CLINICAL PHARMACOLOGY section.)
Potential interactions between paclitaxel, a substrate of CYP3A4, and protease inhibitors (ritonavir, saquinavir, indinavir, and nelfinavir), which are substrates and/or inhibitors of CYP3A4, have not been eva luated in clinical trials.
Reports in the literature suggest that plasma levels of doxorubicin (and its active metabolite doxorubicinol) may be increased when paclitaxel and doxorubicin are used in combination.
Hematology: Paclitaxel therapy should not be administered to patients with baseline neutrophil counts of less than 1,500 cells/mm3. In order to monitor the occurrence of myelotoxicity, it is recommended that frequent peripheral blood cell counts be performed on all patients receiving paclitaxel. Patients should not be retreated with subsequent cycles of paclitaxel until neutrophils recover to a level >1,500 cells/mm3 and platelets recover to a level >100,000 cells/mm3. In the case of severe neutropenia (<500 cells/mm3 for seven days or more) during a course of paclitaxel therapy, a 20% reduction in dose for subsequent courses of therapy is recommended.
Hypersensitivity Reactions: Patients with a history of severe hypersensitivity reactions to products containing Cremophor® EL* (Polyoxyl 35 Castor Oil, NF) (e.g., cyclosporin for injection concentrate and teniposide for injection concentrate) should not be treated with paclitaxel. In order to avoid the occurrence of severe hypersensitivity reactions, all patients treated with paclitaxel should be premedicated with corticosteroids (such as dexamethasone), diphenhydramine and H2 antagonists (such as cimetidine or ranitidine). Minor symptoms such as flushing, skin reactions, dyspnea, hypotension, or tachycardia do not require interruption of therapy. However, severe reactions, such as hypotension requiring treatment, dyspnea requiring bronchodilators, angioedema, or generalized urticaria require immediate discontinuation of paclitaxel and aggressive symptomatic therapy. Patients who have developed severe hypersensitivity reactions should not be rechallenged with paclitaxel.
Cardiovascular: Hypotension, bradycardia, and hypertension have been observed during administration of Paclitaxel Injection, but generally do not require treatment. Occasionally paclitaxel infusions must be interrupted or discontinued because of initial or recurrent hypertension. Frequent vital sign monitoring, particularly during the first hour of paclitaxel infusion, is recommended. Continuous cardiac monitoring is not required except for patients with serious conduction abnormalities. (See WARNINGS section.)
Nervous System: Although the occurrence of peripheral neuropathy is frequent, the development of severe symptomatology is unusual and requires a dose reduction of 20% for all subsequent courses of paclitaxel.
Paclitaxel contains Dehydrated Alcohol USP, 396 mg/mL; consideration should be given to possible CNS and other effects of alcohol. (See PRECAUTIONS: Pediatric Use section.)
Hepatic: There is evidence that the toxicity of paclitaxel is enhanced in patients with elevated liver enzymes. Caution should be exercised when administering paclitaxel to patients with moderate to severe hepatic impairment and dose adjustments should be considered.
Injection Site Reaction: Injection site reactions, including reactions secondary to extravasation, were usually mild and consisted of e