Porfimer sodium, also known by its brand name Photofrin, is a medication used in photodynamic therapy (PDT) for the treatment of certain types of cancer and other medical conditions. Photodynamic therapy is a medical treatment that involves the use of a photosensitizing agent (in this case, porfimer sodium) and a specific type of light to selectively destroy abnormal or cancerous cells.

Porfimer Sodium (Photofrin) is used in photodynamic therapy because of its photosensitizing properties. It is used in the ablation of Barrett's esophagus and esophageal cancer.

Porfimer Sodium Uses:

• Endobronchial cancer (photodynamic therapy):
  • Porfirmer is the key component of treatments for patients with micro-invasive endobronchial non-small cell lung cancer who do not benefit from surgery or radiation.
  • Additionally, it might be utilized in palliative operations to lessen the blockage brought on by NSLC.
• Barrett esophagus dysplasia (photodynamic therapy):
  • For high-grade dysplasia in conditions like Barrett's esophagus, porfirmer is utilized as an ablative substance (in patients who cannot undergo esophagectomy)
• Esophageal cancer (photodynamic therapy):
  • In esophageal carcinomas porfirmer can also be used in the palliation of complete or partial obstruction in patients who are not eligible for Nd: YAG laser therapy.

Porfimer Sodium (Photofrin) Dose in Adults

Porfimer Sodium (Photofrin) Dose in the therapy of Esophageal cancer as well as endobronchial non-small cell lung cancer (photodynamic therapy):

• The medicine is given through an intravenous (IV) injection.
• The dose is calculated based on the person's weight, at a rate of 2 milligrams of porfimer sodium per kilogram of their body weight.
• After receiving the injection, a special laser light is directed at the affected area using an endoscope.
• The laser light activates the porfimer sodium to treat the cancer.
• If necessary, the doctor may also remove damaged tissue during the procedure.
• This treatment can be repeated, but each course of treatment should be at least 30 days apart to allow time for the body to heal.
• A maximum of three courses of treatment may be given for the same condition.

This therapy is used for esophageal cancer and non-small cell lung cancer

Porfimer Sodium (Photofrin) Dose in the therapy of Barrett esophagus dysplasia (photodynamic therapy):

• The medicine is given through an intravenous (IV) injection.
• The dose is calculated based on the person's weight, at a rate of 2 milligrams of porfimer sodium per kilogram of their body weight.
• After receiving the injection, a special laser light is directed at the affected area using an endoscope.
• The laser light activates the porfimer sodium to treat the dysplasia in the esophagus.
• This treatment can be repeated, but each course of treatment should be at least 90 days apart to allow time for the body to heal.
• A maximum of three courses of treatment may be given for the same condition.

Use in Children:

Not indicated.   

Pregnancy Risk Factor C

• In studies with animals, they found some negative effects on reproduction.

Porfimer use during breastfeeding:

• We're not sure if porfimer passes into breast milk. Because it could harm the nursing baby, a decision should be made, considering how important the treatment is for the mother, whether to stop breastfeeding while receiving porfimer treatment or not to use porfimer at all.

Dose in Kidney disease:

• The manufacturer's instructions do not give specific dose adjustments for people with kidney problems because it hasn't been studied in this group.
• However, be cautious when using porfimer if you have kidney issues, as it might take longer for your body to get rid of it.

Dose in Liver disease:

• The manufacturer's instructions don't include specific dose adjustments for individuals with liver problems since it hasn't been studied in this context.
• Nevertheless, it's important to be cautious when using porfimer if you have liver issues because it may take longer for your body to eliminate the medication.

Common Side Effects of Porfimer Sodium (Photofrin):

• Cardiovascular:
  • Chest Pain
• Dermatologic:
  • Skin Photosensitivity
• Central Nervous System:
  • Insomnia
  • Confusion
  • Pain
• Gastrointestinal:
  • Constipation
  • Abdominal Pain
  • Vomiting
  • Esophageal Stenosis
  • Nausea
  • Dysphagia
• Hematologic & Oncologic:
  • Anemia
• Neuromuscular & Skeletal:
  • Back Pain
• Respiratory:
  • Pleural Effusion
  • Dyspnea
  • Bronchial Obstruction
  • Bronchial Plugs
  • Pneumonia
  • Hemoptysis
  • Cough
  • Bronchoconstriction
  • Pharyngitis
• Miscellaneous:
  • Fever
  • Serous Drainage

Less Common Side Effects Of Porfimer Sodium (Photofrin):

• Cardiovascular:
  • Atrial Fibrillation
  • Hypotension
  • Peripheral Edema
  • Cardiac Failure
  • Hypertension
  • Tachycardia
  • Edema
  • Substernal Pain
  • Angina Pectoris
  • Bradycardia
  • Myocardial Infarction
  • Pulmonary Embolism
  • Sick Sinus Syndrome
  • Supraventricular Tachycardia
  • Thrombosis
• Central Nervous System:
  • Anxiety
  • Voice Disorder
• Endocrine & Metabolic:
  • Weight Loss
  • Dehydration
• Gastrointestinal:
  • Anorexia
  • Disease Of Esophagus
  • Hematemesis
  • Tracheoesophageal Fistula
  • Esophageal Perforation
  • Gastric Ulcer
  • Eructation
  • Esophagitis
  • Dyspepsia
  • Diarrhea
  • Melena
  • Intestinal Obstruction
  • Peritonitis
• Genitourinary:
  • Urinary Tract Infection
• Hematologic & Oncologic:
  • Tumor Hemorrhage
  • Pulmonary Hemorrhage
• Hepatic:
  • Jaundice
• Infection:
  • Candidiasis
  • Abscess
• Neuromuscular & Skeletal:
  • Weakness
• Ophthalmic:
  • Diplopia
  • Eye Pain
  • Photophobia
  • Visual Disturbance
• Respiratory:
  • Bronchitis
  • Respiratory Insufficiency
  • Airway Obstruction
  • Bronchospasm
  • Pneumonitis
  • Pulmonary Edema
  • Respiratory Failure
  • Stridor
• Miscellaneous:
  • Ulcer
  • Postoperative Complication

Contraindications to Porfimer Sodium (Photofrin):

Photodynamic therapy (PDT) is not recommended for patients with certain medical conditions, including:

• Current tracheoesophageal or bronchoesophageal fistula: This is an abnormal connection between the trachea (windpipe) or bronchi (airways) and the esophagus, and PDT is not suitable for these patients.
• Tumors eroding into a major blood vessel: PDT may not be safe if the tumor has invaded a major blood vessel.
• Emergency treatment of severe acute respiratory distress caused by an endobronchial lesion: PDT is not appropriate for immediate treatment of severe breathing problems in such cases.
• Esophageal or gastric varices: These are swollen and twisted veins in the esophagus or stomach, and PDT is not recommended if these are present.
• Esophageal ulcers larger than 1 cm in diameter: PDT is not used for treating ulcers of this size.

Additionally, in Canadian labeling, there are additional contraindications, which are not present in U.S. labeling:

• Hypersensitivity to porphyrins: If a person is highly allergic to porphyrins (a group of compounds that includes porfimer sodium), PDT is not recommended.
• For patients with papillary bladder cancer: PDT is contraindicated for those who have previously undergone total bladder radiation or have a bladder with a capacity of less than 200 mL and for patients with advanced bladder tumors greater than stage 1 (T1) with invasive cancer.

Warnings and precautions

Obstructing the airway:

• In the course of treatment, there's a risk of inflammation that could potentially block the airway.
• This is particularly important to be cautious about in patients with endobronchial tumors, especially if they are located in areas where they might block the main airway or if the tumors are large.
• Additionally, the treatment may lead to the formation of necrotic (dead) tissue or mucositis (inflammation of the mucous membranes), which can also contribute to airway obstruction.
• It's crucial to closely monitor patients between the laser therapy and debridement (removal of damaged tissue) stages for signs of respiratory distress.
• In some cases, an urgent bronchoscopy (a procedure to look inside the airways) may be necessary to clear any obstructions like secretions or debris and ensure proper airflow.

Chest pain:

• During the treatment, the body's inflammatory responses to the therapy in the chest area can lead to chest pain that is felt just below the breastbone (substernal chest pain).

Esophageal strictures:

• Esophageal strictures, which are narrowings or tightening of the esophagus, may develop, typically within six months following treatment.
• These strictures might require multiple dilations (stretching) to alleviate them.
• The risk of developing these strictures is higher when there were nodules treated previously in the same area or when the same area is treated again.
• Careful monitoring and management are necessary in such cases to address any esophageal strictures that may arise as a result of the treatment.

Extravasation:

• It's important to prevent extravasation, which is when medicine leaks out of the vein into the surrounding tissue.
• If this happens, keep the affected area away from light.
• However, it's uncertain if antidotes can help in this situation.

Gastroesophageal fistula/perforation:

• There is a serious and potentially life-threatening risk of damage to the gastrointestinal and esophageal tissues, including necrosis (tissue death) and perforation (holes) after treatment.
• For this reason, it's essential to avoid using this treatment in patients with esophageal tumors that are growing into the trachea or bronchial wall.
• Also, it's not recommended for patients who already have a tracheoesophageal or bronchoesophageal fistula, which is an abnormal connection between the trachea or bronchial airways and the esophagus.
• Using the treatment in these cases is not safe.

Hemorrhage:

• Patients who have esophageal varices or tumors that are invading the blood vessels in the lungs are at a higher risk of bleeding, which can sometimes be severe and even fatal, as seen in massive pulmonary hemoptysis (FMH).
• Other factors that increase the risk of FMH include having large tumors located centrally, tumors that form cavities, or tumors that are extensively surrounding the bronchus.
• These patients need close monitoring and appropriate medical care to manage and minimize the risk of bleeding.

Ocular photosensitivity

• People who undergo this treatment might experience discomfort in their eyes when exposed to sunlight or bright lights.
• To protect their eyes, it's recommended that for at least 30 days after the treatment (and until the sensitivity in their eyes gets better), they should wear dark sunglasses that allow less than 4% of white light to pass through, especially when they are outdoors.
• This can help prevent eye discomfort and potential damage from exposure to bright light.

Photosensitivity

• Patients who undergo this treatment often become sensitive to light, both sunlight and bright indoor light (such as fluorescent bulbs and unshaded light bulbs).
• Regular sunscreen that protects against ultraviolet (UV) light won't shield them from light sensitivity reactions caused by visible light.
• This light sensitivity can last for 30 to 90 days or even longer.
• To help with recovery, it's advisable for patients to gradually expose themselves to normal indoor lighting, which helps the body adjust to the treatment.
• They should be educated to test for any remaining light sensitivity before going back out in the sun.
• When resuming exposure to sunlight, it's best to do it gradually, by exposing a small area of skin (but not the face) for 10 minutes.
• If there are no signs of light sensitivity like swelling, redness, or blistering after 24 hours, they can slowly return to their regular outdoor activities.
• If there is light sensitivity, they should wait for two weeks and then try again.

Thromboembolism

• Thromboembolic events, which involve blood clots that can travel through the bloodstream and block blood vessels, might happen, especially in patients who have other risk factors for these events.
• These risk factors can include having advanced cancer, being immobile for a long time, having cardiovascular disease, or recently undergoing major surgery.
• It's essential to be aware of these risks and take appropriate measures to prevent blood clots in such cases.

Barrett's esophagus

• For patients with Barrett esophagus, a rigorous surveillance plan is recommended, which includes conducting an endoscopic biopsy every three months until four consecutive results show no signs of high-grade dysplasia.
• After achieving four negative results, further follow-up should be determined by the physician's judgment.
• It's important to note that the long-term effects of photodynamic therapy in patients with Barrett esophagus are not well understood.
• One common adverse event associated with photodynamic therapy for Barrett esophagus is the development of esophageal strictures, which are narrowings of the esophagus.
• These strictures may require esophageal dilation (stretching) to address them.

Varieties for the esophageal/gastric system:

• This treatment is not suitable for patients who have esophageal or gastric varices because there is a high risk of bleeding in these cases.

Hepatic impairment

• In people with liver problems (hepatic impairment), it may take longer for the body to eliminate the treatment, which can increase the risk of side effects.
• Photosensitivity, the sensitivity to light, might also last longer than 90 days in patients with mild-to-severe liver issues.
• This means they should take extra precautions regarding light exposure and be closely monitored for potential complications.

Renal impairment

• In individuals with kidney problems (renal impairment), the elimination of the treatment might take longer, potentially leading to an increased risk of side effects.
• In cases of severe renal impairment, photosensitivity (sensitivity to light) could last longer than 90 days.
• It's important to take extra precautions regarding light exposure and closely monitor these patients for potential complications.

Monitoring Parameters:

• Extravasation: Watch the injection site carefully during the treatment to catch any medicine leaking into the surrounding tissue.
• Respiratory Distress: Keep an eye on patients with endobronchial tumors, especially between the laser therapy and debridement stages, for signs of breathing problems.
• Photosensitivity: Look for any signs or symptoms of increased sensitivity to light.
• Hemorrhage: Monitor for any signs of bleeding.
• Thromboembolic Events: Pay attention to signs of blood clots, especially in patients with additional risk factors.
• Gastroesophageal Fistulas/Perforation: Watch for any signs of damage to the gastrointestinal and esophageal tissues, such as fistulas or perforations.
• Esophageal Strictures: Keep an eye out for the development of narrowings in the esophagus.

How to administer Porfimer Sodium (Photofrin)?

IV Administration

• Administer slowly as an IV injection over 3 to 5 minutes.
• Be careful to avoid extravasation (medicine leaking into the surrounding tissue). If extravasation happens, protect the affected area from light and sunlight.

Photosensitivity Precautions

• Due to the potential for photosensitivity reactions (sensitivity to light), wear rubber gloves and eye protection while administering the treatment.
• Avoid skin and eye contact during administration. If overexposure occurs, protect the patient from bright light.
• In case of spills, clean them up with a damp cloth, and dispose of contaminated materials correctly.

Mechanism of action of Porfimer Sodium (Photofrin):

• Porfimer's ability to kill cells is linked to both light and oxygen.
• When given, the drug tends to accumulate more in cancerous tissues.
• When these tissues are exposed to laser light at wavelengths greater than 630 nm, it triggers the creation of oxygen free radicals, which can damage and kill cells.
• Additionally, it may lead to the release of thromboxane A, potentially causing blood vessel blockage and tissue death due to a lack of blood supply (ischemic necrosis).

Distribution Volume:

• Approximately 0.49 liters per kilogram (L/kg), as reported in a study by Pereira in 2010. This value gives an idea of how the drug spreads throughout the body.

Protein Binding:

• Porfimer is approximately 90% bound to proteins in the plasma (the liquid part of blood).

Half-life Elimination:

• The half-life is a measure of how long it takes for half of the drug to be removed from the body. For porfimer:
  • After the first dose, the half-life is about 17 days.
  • After the second dose, the half-life is longer, at about 30 days. This means it takes more time for the drug to be eliminated from the body after the second dose.

International Brand Names of Porfimer:

• Photofrin
• Photobarr

Porfimer sodium Brand Names in Pakistan:

Not Available.