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Porfimer Sodium

Pronunciation: PORE-fih-muhr SO-dee-uhm
Class: Antineoplastic

Trade Names

Photofrin
- Cake or Powder for Injection (freeze-dried) 75 mg

Pharmacology

Porfimer is a photosensitizing agent used in the photodynamic therapy (PDT) of tumors. Cellular damage caused by porfimer PDT is a consequence of the propagation of radical reactions. Tumor death also occurs through ischemic necrosis secondary to vascular occlusion that appears to be partly mediated by thromboxane A 2 release. The laser treatment induces a photochemical, not a thermal, effect.

Slideshow: Flashback: FDA Drug Approvals 2013

Pharmacokinetics

Absorption

C max is 15 mcg/mL.

Distribution

Vd is 0.49 L/kg. Protein binding is approximately 90%. Distributed through a variety of tissues and retained mostly in tumors, skin, liver, and spleen.

Elimination

The t ½ is 250 h. Total plasma Cl is 0.051 mL/min/kg.

Indications and Usage

Esophageal cancer; endobronchial non-small cell lung cancer; Barrett esophagus.

Contraindications

PDT

Existing tracheoesophageal or bronchoesophageal fistula; tumors eroding into a major blood vessel.

Porfimer

Porphyria or in patients with known allergies to porphyrins.

Dosage and Administration

Barrett Esophagus
Adults

IV 2 mg/kg as a single slow injection over 3 to 5 min. Patients may receive a second course of PDT a minimum of 90 days after the initial therapy; up to 3 courses of PDT, each separated by a minimum of 90 days can be given to previously treated segment that still show high-grade dysplasia.

Esophageal and Endobronchial Non-Small Cell Lung Cancer
Adults

IV 2 mg/kg as a single slow IV injection over 3 to 5 min. Patients may receive a second course of PDT a minimum of 30 days after the initial therapy; no more than 3 courses of PDT (each separated by a minimum of 30 days) can be given.

General Advice

  • Photodynamic therapy with porfimer is a 2-stage process requiring administration of drug and laser light by trained practitioners. The first stage is the IV injection of porfimer, followed 40 to 50 h later by illumination with laser lights constituting the second stage of therapy. A second laser light application may be given 96 to 120 h after injection, preceded by gentle debridement of residual tumor
  • For IV administration only. Not for intradermal, SC, IM, or intra-arterial administration.
  • Avoid skin and eye contact during reconstitution. Use rubber gloves and eye protection. If accidental skin or eye exposure occurs, protect the exposed area from bright light.
  • Reconstitute powder for injection following manufacturer's guidelines using D5W or sodium chloride 0.9% injection. Shake well until dissolved.
  • Do not reconstitute with other diluents or mix with other medications in same vial.
  • Protect reconstituted solution from light and administer immediately after reconstitution.
  • Administer prescribed dose as a single slow IV injection over 3 to 5 min.
  • Take precautions to prevent extravasation at injection site. If extravasation occurs protect the area from exposure to light.
  • If injection solution is accidentally spilled, wipe up with damp cloth and dispose of in polyethylene bag following institutional guidelines.

Storage/Stability

Store powder for injection at controlled room temperature (68° to 77°F).

Drug Interactions

Compounds that quench active oxygen species or scavenge radicals (eg, dimethyl sulfoxide, beta-carotene, ethanol, mannitol)

Would be expected to decrease PDT activity.

Drugs that decrease clotting, vasoconstriction, or platelet aggregation (eg, thromboxane A 2 inhibitors)

Could decrease the efficacy of PDT.

Glucocorticoid hormones

Given before or concomitantly with PDT, may decrease the efficacy of the treatment.

Photosensitizing agents

Concomitant use of other photosensitizing agents (eg, tetracyclines, sulfonamides, phenothiazines, hypoglycemic agents, thiazide diuretics, griseofulvin) could increase photosensitivity reaction.

Tissue ischemia, allopurinol, calcium channel blockers, and some prostaglandin synthesis inhibitors

Preclinical data also suggest that these could interfere with porfimer.

Laboratory Test Interactions

None well documented.

Adverse Reactions

Adverse reactions reported represent those occurring with porfimer with PDT as a 2-stage process. Adverse reactions listed were reported in at least 5% of patients treated with porfimer-PDT.

Cardiovascular

Atrial fibrillation; cardiac failure; hypotension; tachycardia; hypertension.

CNS

Insomnia; confusion; anxiety; headache; fatigue; depression.

Dermatologic

Photosensitivity; rash; pruritus; sunburn.

EENT

Sinusitis; bronchitis.

GI

Constipation; nausea; abdominal pain; vomiting; dysphagia; esophageal edema; tumor bleeding; hematemesis; dyspepsia; esophageal stricture; diarrhea; eructation; esophagitis; melena; esophageal narrowing; esophageal pain; hiccup; odynophagia.

Metabolic-Nutritional

Weight decrease; dehydration; anorexia.

Respiratory

Pleural effusion; dyspnea; pneumonia; pharyngitis; respiratory insufficiency; cough; tracheoesophageal fistula.

Miscellaneous

Anemia; fever; chest pain; pain; back pain; moniliasis; UTI; peripheral edema; asthenia; substernal chest pain; generalized edema; exudate; obstruction; stricture; ulceration; arthralgia.

Precautions

Pregnancy

Category C .

Lactation

Undetermined.

Children

Safety and efficacy in children have not been established.

Photosensitivity

All patients who receive porfimer sodium will be photosensitive and must observe precautions to avoid exposure of skin and eyes to direct sunlight or bright indoor light for at least 30 days. Exposure of the skin to ambient indoor light is beneficial because the remaining drug will be inactivated gradually and safely through a photobleaching reaction. Therefore, advise patients not to stay in a darkened room during this period and encourage them to expose their skin to ambient indoor light. Ultraviolet (UV) sunscreens are of no value in protecting against photosensitivity reactions.

Chest pain

Patients may complain of substernal chest pain because of inflammatory responses within the area of treatment.

Esophageal strictures

Esophageal strictures as a result of PDT of high-grade dysplasia in Barrett esophagus are common adverse events.

Esophageal varices

Treat patients with esophageal varices with extreme caution. Do not administer light directly to the variceal area because of a high risk of bleeding.

Extravasation risk

Local irritation or phlebitis may occur; in these cases, protect area from light. Refer to your institution-specific protocol.

Fistula

PDT is not recommended if the esophageal tumor is eroding into the trachea or bronchial tree and the likelihood of tracheoesophageal or bronchoesophageal fistula resulting from treatment is sufficiently high.

Ocular sensitivity

Ocular discomfort, commonly described as sensitivity to sun, bright lights, or car headlights has been reported. For 30 days, when outdoors, patients should wear dark sunglasses that have an average white light transmittance of less than 4%.

Respiratory distress

Closely monitor patients with endobronchial lesions between the laser light therapy and the mandatory debridement bronchoscopy for any evidence of respiratory distress.

Treatment-induced inflammation

Use PDT with extreme caution for endobronchial tumors in locations where treatment-induced inflammation could obstruct the main airway.

Use with radiotherapy

Allot sufficient time between the 2 therapies to ensure that the inflammatory response produced by the first treatment has subsided before commencing the second treatment. Allow 2 to 4 wk after PDT before commencing radiotherapy. Similarly, allow 4 wk after completing radiotherapy before giving PDT. Patients with obstructing lung cancer who have received prior radiation therapy have a higher incidence of fatal hemoptysis after PDT.

Patient Information

  • Advise patient, family, or caregiver that medication will be prepared and administered by health care provider in a health care setting and that laser light treatment will be administered 40 to 50 h after porfimer administration has been completed.
  • Advise patient, family, or caregiver that a second laser light treatment may be administered 96 to 120 h after the porfimer has been administered.
  • Caution patient that therapy will make them extremely sensitive to light (photosensitivity) for up to 30 days and to avoid exposure of skin and eyes to direct sunlight (including skylights and undraped windows) or bright indoor light (eg, examination lamps, dental lamps, unshaded light bulbs at close range).
  • Advise patient to cover the skin as much as possible during daylight hours (eg, long-sleeved shirts, slacks, gloves, socks) even on cloudy days or when in a car.
  • Advise patient to wear dark sunglasses when exposed to sunlight, bright lights, or car headlights to prevent eye discomfort. Advise patient that sunglasses should have an average white light transmittance of less than 4% and to check with an eye doctor if unsure.
  • Caution patient that OTC sunscreens will not protect them against photosensitivity reactions.
  • Advise patient not to stay in darkened room but to expose the skin to soft indoor light (eg, shaded lamps).
  • Instruct patient how to check for residual photosensitivity after 30 days (eg, expose small area of skin other than face to sunlight for 10 min and note degree of redness, swelling, or blistering that occurs over the next 24 h).
  • Advise patient, family, or caregiver to immediately report any of the following to health care provider: shortness of breath or difficulty breathing; severe sunburn reaction.
  • Advise patient, family, or caregiver to report persistent chest pain to health care provider.
  • Advise women of childbearing potential to avoid becoming pregnant during therapy by using effective contraception.

Copyright © 2009 Wolters Kluwer Health.

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