Overview
11 DESCRIPTION Porfimer sodium is a photoactivated radical generator. Porfimer sodium is a mixture of oligomers formed by ether and ester linkages of up to eight porphyrin units. The structural formula below is representative of the components of porfimer sodium. PHOTOFRIN (porfimer sodium) for injection, for intravenous use, is supplied in a single-dose vial as dark red to reddish brown...
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action The cytotoxic and antitumor actions of PHOTOFRIN are light and oxygen dependent. Photodynamic therapy (PDT) with PHOTOFRIN is a two-stage process. The first stage is the intravenous administration of PHOTOFRIN. Clearance from a variety of tissues occurs over 40-72 hours, but tumors, skin, and organs of the reticuloendothelial system (including liver and spleen) retain PHOTOFRIN for a longer period. The second stage is the illumination with 630 nm wavelength laser light. Tumor selectivity in treatment occurs through a combination of selective retention of PHOTOFRIN and selective delivery of light. Cellular damage caused by PDT with PHOTOFRIN is a consequence of the propagation of radical reactions.
Indications
- 1 INDICATIONS AND USAGE PHOTOFRIN is a photoactivated radical generator indicated for: Esophageal Cancer ( 1.1 ) Palliation of patients with completely obstructing esophageal cancer, or of patients with partially obstructing esophageal cancer who, in the opinion of their physician, cannot be satisfactorily treated with Nd:YAG laser therapy Endobronchial Cancer ( 1.2 ) Treatment of microinvasive endobronchial non-small-cell lung cancer (NSCLC) in patients for whom surgery and radiotherapy are not indicated Reduction of obstruction and palliation of symptoms in patients with completely or...
Common Doses
- 2 mg
- 31.8 mL
- 2.5 mg
- 75 mg
Dosage
2 DOSAGE AND ADMINISTRATION PHOTOFRIN ( 2.1 ) PHOTOFRIN administration: 2 mg/kg intravenous Photoactivation ( 2.2 ) Esophageal Cancer Laser light dose of 300 J/cm of fiber optic diffuser length 40–50 hours following injection with PHOTOFRIN; repeated, if needed, 96-120 hours after initial injection Endobronchial Cancer Laser light dose of 200 J/cm of fiber optic diffuser length 40–50 hours following injection with PHOTOFRIN; repeated, if needed, after gentle debridement of residual tumor 96-120 hours after initial injection High-Grade Dysplasia in Barrett’s Esophagus Laser light dose of 130...
Contraindications
- 4 CONTRAINDICATIONS PHOTOFRIN is contraindicated in patients with porphyria. Photodynamic therapy (PDT) is contraindicated in patients with an existing tracheoesophageal or bronchoesophageal fistula. PDT is contraindicated in patients with tumors eroding into a major blood vessel. PDT is not suitable for emergency treatment of patients with severe acute respiratory distress caused by an obstructing endobronchial lesion because 40 to 50 hours are required between injection with PHOTOFRIN and laser light treatment.
Side Effects
- 6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling: Gastroesophageal Fistula and Perforation [see Warnings and Precautions ( 5.1 )] Pulmonary and Gastroesophageal Hemorrhage [see Warnings and Precautions ( 5.2 )] High-Grade Dysplasia (HGD) in Barrett’s Esophagus (BE) [see Warnings and Precautions ( 5.3 )] Photosensitivity [see Warnings and Precautions ( 5.4 )] Ocular Sensitivity [see Warnings and Precautions ( 5.5 )] Use Before or After Radiotherapy [see Warnings and Precautions ( 5.
Interactions
- 7 DRUG INTERACTIONS Other Photosensitizing Agents : May increase the risk of photosensitivity reaction ( 7.1 ) 7.1 Use with Other Photosensitizing Agents PHOTOFRIN can cause photosensitivity. The concomitant use of PHOTOFRIN with other photosensitizing agents (e.g., tetracyclines, sulfonamides, phenothiazines, sulfonylurea hypoglycemic agents, thiazide diuretics, griseofulvin, and fluoroquinolones) may increase the risk of a photosensitivity reaction. Avoid the concomitant use of PHOTOFRIN with other products known to cause photosensitivity.