PHOTREXA VISCOUS IN DEXTRAN 20%
Clinical safety rating: caution
Comprehensive clinical and safety monograph for PHOTREXA VISCOUS IN DEXTRAN 20% (PHOTREXA VISCOUS IN DEXTRAN 20%).
Photosensitizer activation by light to produce reactive oxygen species, causing endothelial damage in choroidal neovascularization.
| Metabolism | Eliminated by unchanged excretion in feces via biliary system; minor hepatic metabolism. |
| Excretion | Primarily renal excretion as intact drug; <5% metabolized; 90% excreted unchanged in urine within 24 hours. |
| Half-life | Terminal half-life approximately 15–20 minutes; rapid clearance due to renal elimination and tissue binding. |
| Protein binding | Approximately 90–95% bound to albumin and other serum proteins. |
| Volume of Distribution | 0.2–0.3 L/kg; confined primarily to vascular and extracellular spaces due to high protein binding and hydrophilic nature. |
| Bioavailability | Not applicable for topical ocular use; negligible systemic absorption (bioavailability <0.1% after topical application). |
| Onset of Action | Immediate upon topical application to ocular surface; clinical photodynamic effect within 5 minutes after activation with appropriate light source. |
| Duration of Action | Photodynamic effect persists for 1–2 hours post-activation; clinical effect limited to single treatment session. |
Photrexa Viscous (riboflavin 5'-phosphate) in Dextran 20% is administered topically to the cornea after epithelial removal, 1 drop every 2 minutes for 30 minutes (total 15 drops) prior to UV-A irradiation, then continued during irradiation per protocol.
| Dosage form | SOLUTION/DROPS |
| Renal impairment | No renal adjustment required; drug is not systemically absorbed. |
| Liver impairment | No hepatic adjustment required; drug is not systemically absorbed. |
| Pediatric use | Based on limited data, same dosing as adults: topical corneal application after epithelial removal, 1 drop every 2 minutes for 30 minutes prior to and during UV-A irradiation. |
| Geriatric use | No specific adjustment; same dosing as adults. Consider corneal healing delays in elderly. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for PHOTREXA VISCOUS IN DEXTRAN 20% (PHOTREXA VISCOUS IN DEXTRAN 20%).
| Breastfeeding | M/P ratio not determined; systemic absorption minimal after topical ocular use; unlikely to be excreted in breast milk in clinically significant amounts; use with caution, consider benefit vs risk. |
| Teratogenic Risk | No evidence of teratogenicity in animal studies; systemic absorption negligible following ocular administration; FDA Pregnancy Category B for components; risk to fetus in all trimesters considered minimal due to lack of systemic exposure. |
| Fetal Monitoring |
■ FDA Black Box Warning
No FDA boxed warning.
| Serious Effects |
Known hypersensitivity to verteporfin or any component; porphyria; severe hepatic impairment.
| Precautions | Anaphylaxis, chest pain, vasovagal reactions, extravasation, photosensitivity, decreased vision, hemorrhage, vitreous detachment, intraocular inflammation, retinal tear, retinal detachment; avoid extravasation. |
Loading safety data…
| No specific monitoring required due to negligible systemic absorption; standard observation for local ocular effects. |
| Fertility Effects | No adverse effects on fertility reported in animal studies; unlikely to impact human fertility due to minimal systemic absorption. |