Visudyne

Visudyne - General Information

Visudyne, otherwise known as benzoporphyrin derivative (trade name Visudyne®), is a medication used as a photosensitizer for photodynamic therapy to eliminate the abnormal blood vessels in the eye associated with conditions such as the wet form of macular degeneration. Visudyne accumulates in these abnormal blood vessels and, when stimulated by nonthermal red light with a wavelength of 693 nm in the presence of oxygen, produces highly reactive short-lived singlet oxygen and other reactive oxygen radicals, resulting in local damage to the endothelium and blockage of the vessels.

Pharmacology of Visudyne

Visudyne, otherwise known as benzoporphyrin derivative, is a medication used in conjunction with laser treatment to eliminate the abnormal blood vessels in the eye associated with conditions such as the wet form of macular degeneration. Visudyne accumulates in these abnormal blood vessels and, when stimulated by nonthermal red light with a wavelength of 693 nm in the presence of oxygen, produces highly reactive short-lived singlet oxygen and other reactive oxygen radicals, resulting in local damage to the endothelium and blockage of the vessels.

Visudyne for patients

Patients who receive VISUDYNE will become temporarily photosensitive after the infusion. Patients should wear a wrist band to remind them to avoid direct sunlight for 5 days. During that period, patients should avoid exposure of unprotected skin, eyes or other body organs to direct sunlight or bright indoor light. Sources of bright light include, but are not limited to, tanning salons, bright halogen lighting and high power lighting used in surgical operating rooms or dental offices. Prolonged exposure to light from light-emitting medical devices such as pulse oximeters should also be avoided for 5 days following VISUDYNE administration.

If treated patients must go outdoors in daylight during the first 5 days after treatment, they should protect all parts of their skin and their eyes by wearing protective clothing and dark sunglasses. UV sunscreens are not effective in protecting against photosensitivity reactions because photoactivation of the residual drug in the skin can be caused by visible light.

Patients should not stay in the dark and should be encouraged to expose their skin to ambient indoor light, as it will help inactivate the drug in the skin through a process called photobleaching.

Visudyne Interactions

Drug interaction studies in humans have not been conducted with VISUDYNE. Verteporfin is rapidly eliminated by the liver, mainly as unchanged drug. Metabolism is limited and occurs by liver and plasma esterases. Microsomal cytochrome P450 does not appear to play a role in verteporfin metabolism.

Based on the mechanism of action of verteporfin, many drugs used concomitantly could influence the effect of VISUDYNE therapy. Possible examples include the following: Calcium channel blockers, polymyxin B or radiation therapy could enhance the rate of VISUDYNE uptake by the vascular endothelium. Other photosensitizing agents (e.g., tetracyclines, sulfonamides, phenothiazines, sulfonylurea hypoglycemic agents, thiazide diuretics and griseofulvin) could increase the potential for skin photosensitivity reactions. Compounds that quench active oxygen species or scavenge radicals, such as dimethyl sulfoxide, b -carotene, ethanol, formate and mannitol, would be expected to decrease VISUDYNE activity. Drugs that decrease clotting, vasoconstriction or platelet aggregation, e.g., thromboxane A₂ inhibitors, could also decrease the efficacy of VISUDYNE therapy.

Visudyne Contraindications

VISUDYNE is contraindicated for patients with porphyria or a known hypersensitivity to any component of this preparation.

Additional information about Visudyne

Visudyne Indication: For the treatment of patients with predominantly classic subfoveal choroidal neovascularization due to age-related macular degeneration, pathologic myopia or presumed ocular histoplasmosis.
Mechanism Of Action: Visudyne is transported in the plasma primarily by lipoproteins. Once verteporfin is activated by light in the presence of oxygen, highly reactive, short-lived singlet oxygen and reactive oxygen radicals are generated. Light activation of verteporfin results in local damage to neovascular endothelium, resulting in vessel occlusion. Damaged endothelium is known to release procoagulant and vasoactive factors through the lipo-oxygenase (leukotriene) and cyclo-oxygenase (eicosanoids such as thromboxane) pathways, resulting in platelet aggregation, fibrin clot formation and vasoconstriction. Visudyne appears to somewhat preferentially accumulate in neovasculature, including choroidal neovasculature. However, animal models indicate that the drug is also present in the retina.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Verteporfin
Synonyms: Not Available
Drug Category: Antineoplastic Agents; Photosensitizing Agents; Antineovascularisation Agents
Drug Type: Small Molecule; Approved

Other Brand Names containing Verteporfin: Visudyne;
Absorption: Not Available
Toxicity (Overdose): Overdose of drug and/or light in the treated eye may result in nonperfusion of normal retinal vessels with the possibility of severe decrease in vision that could be permanent. An overdose of drug will also result in the prolongation of the period during which the patient remains photosensitive to bright light.
Protein Binding: Not Available
Biotransformation: Metabolized to a small extent to its diacid metabolite by liver and plasma esterases. NADPH-dependent liver enzyme systems (including the cytochrome P450 isozymes) do not appear to play a role in the metabolism of verteporfin.
Half Life: Following intravenous infusion, verteporfin exhibits a bi-exponential elimination with a terminal elimination half-life of approximately 5-6 hours. Mild hepatic insufficiency increases half-life by approximately 20%.
Dosage Forms of Visudyne: Powder, for solution Intravenous
Chemical IUPAC Name: Not Available
Chemical Formula: C41H42N4O8
Verteporfin on Wikipedia: https://en.wikipedia.org/wiki/Verteporfin
Organisms Affected: Humans and other mammals