porfimer

REMS

Part of photodynamic therapy for:
- Esophageal cancer that has completely or partially obstructed the esophagus and cannot be treated with Nd:YAG laser therapy,
- Reduction of obstruction and palliation of symptoms in patients with completely or partially obstructive endobronchial non-small lung cancer,
- Microinvasive endobronchial non-small cell lung cancer when surgery or radiation are not options,
- High grade dysplasia due to Barrett's esophagus in patients who are unable to have esophagectomy.

Action ⬆ ⬇

Porfimer is retained by the tumor, which is then treated with a laser light. When porfimer absorbs the light, a photochemical reaction occurs, causing cellular damage.
Thromboxane A is also produced, causing additional local tumor necrosis.

Therapeutic effects:

Shrinkage of esophageal or endobronchial tumors.

Pharmacokinetics ⬆ ⬇

Absorption: IV administration results in complete bioavailability.

Distribution: Retained for a longer period by tumors, skin, and reticuloendothelial tissue.

Protein Binding: 90%.

Metabolism/Excretion: Unknown.

Half-Life: 410 hr (first dose); 725 hr (2nd dose).

Time/Action Profile ⬆ ⬇

(antitumor effect)

ROUTE	ONSET	PEAK	DURATION
IV	rapid‡	unknown	unknown

‡After laser light treatment.

Contraind./Precautions ⬆ ⬇

Contraindicated in:

History of porphyria or hypersensitivity to porphyrins;
Tracheobronchial or bronchoesophageal fistulas or tumors with potential to erode into a major blood vessel or the trachea;
Not suitable for acute treatment of patients with severe respiratory distress due to obstructive endotrachial lesion;
Tumors eroding into a major blood vessel;
Esophageal or gastric varices, or esophageal ulcers >1 cm in diameter;
Should not be used within 4 wk of radiation therapy.
OB: Pregnancy;
Lactation: Lactation.

Use Cautiously in:

Direct sunlight or bright indoor light (photosensitivity will occur);
Hepatic or renal impairment (may require more than 90 days of precautionary photosensitivity measures);
Rep: Women of reproductive potential and men with female partners of reproductive potential;
Pedi: Safety and effectiveness not established.

Adv. Reactions/Side Effects ⬆ ⬇

CV: chest pain, HF, atrial fibrillation, edema, hypertension, hypotension, tachycardia, THROMBOEMBOLIC EVENTS

Derm: photosensitivity

F and E: dehydration

GI: abdominal pain, constipation, esophageal stricture, nausea, vomiting, GI BLEEDING, GI/ESOPHAGEAL PERFORATION, anorexia, diarrhea, dyspepsia, eructation, esophageal tumor bleeding

GU: moniliasis, urinary tract infection

Hemat: anemia

Metab: ↓weight

Neuro: insomnia, anxiety, confusion, weakness

Resp: mucositis reaction, dyspnea, pharyngitis, pleural effusion, pneumonia, cough, PULMONARY BLEEDING, RESPIRATORY DISTRESS, tracheoesophageal fistula

Misc: fever, pain

Interactions ⬆ ⬇

Drug-drug:

Photosensitizing effect may be ↑ by concurrent use of tetracyclines, sulfonamides, phenothiazines, sulfonylureas, or thiazide diuretics.
The effects of photodynamic therapy may be altered by calcium channel blockers, corticosteroids, ethanol, mannitol, dimethyl sulfoxide, beta carotene, vasoconstrictors, or agents that affect clotting.

Route/Dosage ⬆ ⬇

IV (Adults ): 2 mg/kg followed 40–50 hr later by laser light therapy. A second session of laser light therapy may be given 96–120 hr after porfimer and may be preceded by gentle tumor debridement. Up to three treatments may be given, with a 30–day minimum interval between treatments.

Availability ⬆ ⬇

Powder for injection: 75 mg/vial

Assessment ⬆ ⬇

Assess patient for substernal chest pain after therapy. May result from an inflammatory response in the treatment area. May require opioid analgesics to relieve symptoms.
Before each new course of therapy, the patient should be examined for either bronchoesophageal or tracheoesophageal fistula.

Lab Test Considerations:

Verify negative pregnancy test before starting therapy.May cause ↓ in hemoglobin and hematocrit as a result of tumor bleeding induced by photodynamic therapy.

Implementation ⬆ ⬇

Avoid contact with skin and eyes during preparation. Use of disposable gloves and eye covering is recommended. If exposure occurs, follow directions for preventing a photosensitivity reaction (see Patient/Family Teaching).
- Porfimer spills may be wiped up with a damp cloth. Contaminated materials should be disposed in a polyethylene bag, following regulations for handling hazardous waste.

IV Administration:

IV Push: Diluent: Dilute 75–mg vial with 31.8 mL of D5W or 0.9% NaCl. Protect reconstituted solution from bright light and use immediately.Concentration: 2.5 mg/mL.
Rate: Administer over 3–5 min. If solution extravasates, protect injection site from bright light for 30 days.

Patient/Family Teaching ⬆ ⬇

Instruct patient in precautions to prevent photosensitivity reactions. Precautions should be used for 30 days (90 days if patient has liver impairment). Avoid exposure of skin and eyes to direct sunlight and bright indoor light (dental or operating room lights, unshaded light bulbs at close proximity).
Porfimer is slowly and safely inactivated by ambient indoor light. Patients should avoid spending long periods in darkened rooms and should expose themselves to ambient indoor light.
Patients may test themselves for residual photosensitivity by exposing a small portion of skin to sunlight for 10 min. If erythema, blistering, or edema does not occur within 24 hr, patients may gradually increase their exposure to bright lights or sunlight. If a photosensitivity reaction occurs, patient should avoid exposure for an additional 2 wk, then retest skin. Do not use face for photosensitivity testing because skin around eyes may be more sensitive. Before traveling to geographic areas that have increased light, patients should retest their photosensitivity level.
Ultraviolet sunscreens offer no protection against a photosensitivity reaction because porfimer is activated by visible light.
Ocular sensitivity to sunlight, bright lights, or car headlights may occur. Patients should wear dark glasses that transmit <4% of white light when outside for approximately 30 days after administration of porfimer.
Advise patient to notify health care professional if ocular sensitivity, chest pain, respiratory distress, or esophageal strictures occur.
Rep: May cause fetal harm. Advise females of reproductive potential and males with female partners of reproductive potential to use effective contraception during therapy and to avoid breastfeeding for 5 mos after final dose.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇