Verteporfin is a medication used in photodynamic therapy to treat certain eye conditions, notably age-related macular degeneration (AMD). It's specifically indicated for the treatment of predominantly classic subfoveal choroidal neovascularization (CNV) due to AMD.

Photodynamic therapy (PDT) involves administering a light-sensitive drug, in this case, verteporfin, followed by exposure to a specific wavelength of light. When activated by light, verteporfin produces a reaction that selectively damages abnormal blood vessels in the eye, such as those associated with AMD. This helps to slow the progression of the disease and prevent further vision loss.

For the following reasons, verteporfin (visudyne) is prescribed to treat conventional subfoveal choroidal neovascularization:

• Age-related macular degeneration
• Pathologic myopia
• Presumed ocular histoplasmosis.

Limitations of use:

• Verteporfin should not be used to treat subfoveal choroidal neovascularization that is mostly occult, according to available research.

Verteporfin dose in adult

• Verteporfin therapy is carried out in two main steps.
• First, the drug verteporfin is given through an infusion, which means it’s administered directly into the bloodstream.
• Then, the infused drug is activated using a special type of light from a nonthermal diode laser.
• This activation helps the drug target and treat abnormal blood vessels in the eye.

Verteporfin Dose in the treatment of Subfoveal choroidal neovascularization:

• Verteporfin is dosed at 6 mg per square meter of body surface area. It is administered intravenously.
• The treatment can be repeated at 3-month intervals if there is evidence of ongoing choroidal neovascular leakage, based on medical assessments.
• This dosing schedule allows for periodic reevaluation and treatment adjustment to effectively manage the condition.

Note:

• When treating patients with subfoveal choroidal neovascularization who have eligible lesions in both eyes, the more aggressive lesion should be targeted first.
• After a successful and safe initial treatment, the second eye can be treated one week later.
• For patients who have previously undergone verteporfin therapy and have demonstrated a good safety profile, both eyes may be treated at the same time, approximately 3 months after the initial treatment.
• In such concurrent treatments, the more aggressive lesion should be addressed first, followed immediately by the second eye.
• It’s crucial that the light treatment for the second eye starts no later than 20 minutes from the beginning of the verteporfin infusion.

Verteporfin Dose in Children

Not applicable

Pregnancy Risk Factor C

• Verteporfin is classified as Pregnancy Risk Factor C.
• This classification means that adverse effects have been observed in animal reproduction studies when verteporfin was administered to pregnant animals.

Verteporfin use during breastfeeding:

• Verteporfin and its metabolite have been found to be excreted in breast milk, with milk concentrations reaching up to 66% of the plasma levels in one reported case following infusion.
• Furthermore, the metabolite was detectable in breast milk even 48 hours after the infusion.
• Given the potential for serious adverse reactions in a nursing infant, the manufacturer advises that breastfeeding should either be discontinued or the treatment with verteporfin should be postponed.

Verteporfin Dose in Renal Disease:

• Verteporfin does not require dosage adjustments according to the manufacturer's labeling, even for patients with renal impairment.
• This is primarily because verteporfin is eliminated from the body mostly through the feces, not the kidneys.

Verteporfin Dose in Liver Disease:

• For patients with mild hepatic impairment, there are no specific dosage adjustments recommended for verteporfin according to the manufacturer's labeling.
• In cases of moderate-to-severe hepatic impairment, the manufacturer’s labeling does not provide specific dosage adjustments either. This is primarily because verteporfin has not been studied extensively in patients with moderate-to-severe liver function impairment.

Common Side Effects of Verteporfin Include:

• Ophthalmic:
  • Blurred Vision
  • Photopsia
  • Decreased Visual Acuity
  • Visual Field Defect (Including Scotoma)
• Local:
  • Injection Site Reaction Including
    • Pain At Injection Site
    • Rash At Injection Site
    • Local Discoloration
    • Local Edema
    • Extravasation
    • Inflammation At Injection Site
    • Local Hemorrhage

Less Common Side Effects of Verteporfin Include:

• Genitourinary:
  • Prostatic Disease
• Cardiovascular:
  • Peripheral Vascular Disease
  • Varicose Veins
  • Atrial Fibrillation
  • Hypertension
• Endocrine & Metabolic:
  • Albuminuria
• Central Nervous System:
  • Disturbed Sleep
  • Vertigo
  • Hypoesthesia
  • Myasthenia
• Dermatologic:
  • Eczema
  • Skin Photosensitivity
• Gastrointestinal:
  • Constipation
  • Nausea
• Hepatic:
  • Increased Liver Enzymes
• Neuromuscular & Skeletal:
  • Back Pain (Primarily During Infusion)
  • Weakness
  • Arthralgia
  • Arthropathy
• Miscellaneous:
  • Fever
• Ophthalmic:
  • Severe Vision Loss
  • Xerophthalmia
  • Cataract
  • Conjunctivitis
  • Conjunctival Injection
  • Diplopia
  • Abnormal Lacrimation
  • Blepharitis
  • Eye Pruritus
• Respiratory:
  • Cough
  • Pneumonia
  • Flu-Like Symptoms
  • Pharyngitis
• Otic:
  • Hearing Loss
• Hematologic & Oncologic:
  • Anemia
  • Gastrointestinal Carcinoma
  • Leukocytosis
  • Leukopenia
• Renal:
  • Increased Serum Creatinine

Frequency Not Defined:

• Cardiovascular:
  • Chest Pain
  • Vasodepressor Syncope
• Hypersensitivity:
  • Hypersensitivity Reaction
• Neuromuscular & Skeletal:
  • Musculoskeletal Pain (During Infusion)
• Ophthalmic:
  • Retinal Detachment
  • Retinal Ischemia
  • Retinal Pigment Epithelium Tear

Contraindication to Verteporfin Include:

• If someone is allergic to verteporfin or any part of the treatment, or if they have porphyria (a rare blood disorder), they shouldn’t use verteporfin.
• In Canada, there's an extra rule: if someone has severe liver problems, they shouldn't use it either. These are important rules to follow to make sure the treatment is safe and effective for everyone.

Warnings and Precautions

Extravasation:

• If verteporfin leaks from the vein during injection, it can cause severe pain, swelling, inflammation, or a change in skin color at the injection site, especially if the area is exposed to light.
• To prevent this, doctors should use standard precautions like making sure the IV line is flowing freely and using the largest arm vein available, preferably in the elbow area.
• It's best to avoid smaller veins, like those on the back of the hand.
• If leakage happens, the infusion should be stopped right away, and the area should be kept away from direct light until the swelling and discoloration go away.
• Cold compresses and pain medication can help manage any discomfort.

Infusion reactions

• Rarely, during the infusion of verteporfin, some people might experience infusion reactions. These reactions can include symptoms like chest pain, difficulty breathing (dyspnea), flushing, fainting (syncope), or a sudden drop in heart rate (vasovagal reaction).

Ophthalmic effects

• Verteporfin can sometimes cause vision problems like unusual vision, reduced vision, or changes in the visual field. These effects might make it difficult for someone to drive or operate machinery safely. It's essential for individuals experiencing such visual disturbances to avoid activities requiring full attention and coordination until their vision returns to normal.

Photosensitivity

• After receiving verteporfin treatment, it's crucial to avoid exposing your skin or eyes directly to sunlight or bright indoor light for five days.
• However, it's okay to be in regular indoor lighting.
• If emergency surgery is needed within 48 hours after treatment, try to shield as much internal tissue as possible from intense light.
• Additionally, for five days after treatment, it's best to steer clear of prolonged exposure to light from medical devices like pulse oximeters.
• These precautions help prevent potential reactions to light and ensure the treatment's effectiveness.

Verteporfin: Drug Interaction

Monitor:

During Infusion:

• Keep an eye on the intravenous site to prevent leakage.
• Make sure the infusion is going smoothly to avoid any spills.

Monitoring Choroidal Neovascular Leakage:

• Have a fluorescein angiography done every 3 months.
• If any leakage is found, repeat the therapy to keep it in check.

How to administer Verteporfin?

IV Administration:

• Infuse at a rate of 3 mL/minute over 10 minutes using a syringe pump and an in-line filter.
• Ensure a free-flowing IV line before starting the infusion.
• Use the largest arm vein, especially in elderly patients, and avoid small veins in the back of the hand to prevent extravasation.
• If extravasation occurs, protect the site from light and stop the infusion immediately.

Extravasation Management:

• Stop the infusion and protect the area from direct light until swelling and discoloration fade.
• Apply cold compresses to the injection site to decrease the chance of severe burns.

Safety Precautions:

• Avoid skin and eye contact during preparation and administration.
• If contact occurs, shield the area from bright light and wipe any spills with a damp cloth.
• Use rubber gloves and dispose of all materials properly.

Light Administration:

• After IV infusion, activate verteporfin using a nonthermal diode laser.
• Ensure the laser system provides stable power output at 689 ± 3 nm wavelength.
• Start light delivery 15 minutes after the start of the infusion.
• Administer a light dose of 50 J/cm² of neovascular lesion over 83 seconds at an intensity of 600 mW/cm².
• Refer to the manufacturer's package insert for approved laser systems and detailed instructions on determining lesion size, treatment spot size, and light administration.

Mechanism of action of Verteporfin:

• After being administered intravenously, verteporfin is carried by lipoproteins to the abnormal blood vessels in the affected eye(s), such as those in the choroidal neovasculature and retina.
• To become effective, verteporfin requires activation by nonthermal red light.
• This light activation causes localized damage to the endothelial cells lining the blood vessels, leading to temporary blockage of the vessels in the choroid layer of the eye.
• This process helps to control and manage conditions like choroidal neovascularization by limiting the blood supply to abnormal vessels, thereby reducing their growth and associated complications.

Metabolism:

• Verteporfin is primarily metabolized in the liver and by plasma esterases.
• This metabolism results in the formation of a diacid metabolite.

Half-life Elimination:

• The terminal half-life of verteporfin ranges from 5 to 6 hours.
• Its elimination follows a biexponential pattern.

Excretion:

• Verteporfin is predominantly excreted in the feces.
• Less than 0.01% of the drug is excreted in urine.

International Brands of Verteporfin:

• Visudine
• Visudyne

Verteporfin Brands in Pakistan: