Dosing and uses of Photrexa, Photrexa Viscous (riboflavin 5´phosphate ophthalmic)
Adult dosage forms and strengths
topical ophthalmic solution in 3mL glass syringe
- 0.146% (ie, 1.46mg/mL) in 20% dextran (Photrexa Viscous)
- 0.146% (Photrexa)
Keratoconus or Corneal Ectasia
Indicated for use in corneal collagen cross-linking in combination with the KXL System for the treatment of progressive keratoconus or for corneal ectasia following refractive surgery
Using topical anesthesia, debride the epithelium to a diameter of ~9 mm using standard aseptic technique
NOTE: Both Photrexa and Photrexa Viscous are used topically during the procedure
Post epithelial debridement, instill 1 drop of Photrexa Viscous topically on the eye q2minutes for 30 minutes
At the end of the 30-minute soaking period, examine the eye under the slit lamp for the presence of a yellow flare in the anterior chamber; if the yellow flare is not detected, instill 1 drop of Photrexa Viscous q2minutes for an additional 2-3 drops and recheck for the presence of a yellow flare; this process can be repeated as necessary
Once the yellow flare is observed, perform ultrasound pachymetry
If corneal thickness is <400 micrometers, instill 2 drops of Photrexa q5-10 seconds until the corneal thickness increases to at least 400 micrometers
Irradiation should not be performed unless this 400-micrometer threshold is met and the yellow flare is seen
Irradiate the eye for 30 continuous minutes at 3mW/cm² at a wavelength of 365 nm, centered over the cornea, using the KXL System as per the instructions in the manuaL
During irradiation, continue topical instillation of Photrexa Viscous onto the eye q2minutes for the 30-minute irradiation period
Pediatric dosage forms and strengths
topical ophthalmic solution in 3mL glass syringe
- 0.146% (ie, 1.46mg/mL) in 20% dextran (Photrexa Viscous)
- 0.146% (Photrexa)
Keratoconus
Indicated for use in corneal collagen cross-linking in combination with the KXL System for the treatment of progressive keratoconus
<14 years: Safety and efficacy not established
Using topical anesthesia, debride the epithelium to a diameter of ~9 mm using standard aseptic technique
NOTE: Both Photrexa and Photrexa Viscous are used topically during the procedure
Post epithelial debridement, instill 1 drop of Photrexa Viscous topically on the eye q2minutes for 30 minutes
At the end of the 30-minute soaking period, examine the eye under the slit lamp for the presence of a yellow flare in the anterior chamber; if the yellow flare is not detected, instill 1 drop of Photrexa Viscous q2minutes for an additional 2-3 drops and recheck for the presence of a yellow flare; this process can be repeated as necessary
Once the yellow flare is observed, perform ultrasound pachymetry
If corneal thickness is <400 micrometers, instill 2 drops of Photrexa q5-10 seconds until the corneal thickness increases to at least 400 micrometers
Irradiation should not be performed unless this 400-micrometer threshold is met and the yellow flare is seen
Irradiate the eye for 30 continuous minutes at 3mW/cm² at a wavelength of 365 nm, centered over the cornea, using the KXL System as per the instructions in the manuaL
During irradiation, continue topical instillation of Photrexa Viscous onto the eye q2minutes for the 30-minute irradiation period
Photrexa, Photrexa Viscous (riboflavin 5´phosphate ophthalmic) adverse (side) effects
>10%
Corneal opacity (64%)
Punctate keratitis (25%)
Corneal striae (24%)
Corneal epithelium defect (24%)
Eye pain (17%)
Vision blurred (16%)
Foreign body sensation in eyes (15%)
Ocular hyperemia (14%)
Photophobia (11%)
Visual acuity reduced (10%)
1-10%
Headache (4-8%)
Dry eye (6%)
Eyelid edema (5%)
Lacrimation increased (5%)
Anterior chamber flare (4%)
Glare (4%)
Visual impairment (3%)
Corneal disorder (3%)
Corneal edema (3%)
Vitreous detachment (2%)
Anterior chamber cell (2%)
Diplopia (2%)
Eye complication associated with device (2%)
Eye discharge (2%)
Eye edema (2%)
Eye pruritus (2%)
Asthenopia (1%)
Corneal thinning (1%)
Halo vision (1%)
Keratitis (1%)
Meibomian gland dysfunction (1%)
Warnings
Contraindications
None
Cautions
Ulcerative keratitis can occur; monitor for resolution of epithelial defects
Pregnancy
Pregnancy
Animal development and reproduction studies have not been conducted
Since it is not known whether the corneal collagen cross-linking procedure can cause fetal harm or affect reproduction capacity, it should not be performed on pregnant women
Lactation
Unknown if distributed in human breast milk; weigh benefits against risks
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Photrexa, Photrexa Viscous (riboflavin 5´phosphate ophthalmic)
Mechanism of action
Riboflavin 5´-phosphate sodium (vitamin B-2) is the precursor of 2 coenzymes, flavin adenine dinucleotide and flavin mononucleotide, which catalyze oxidation/reduction reactions involved in a number of metabolic pathways
Under the conditions used for corneal collagen cross-linking, riboflavin 5´-phosphate functions as a photoenhancer and generates singlet oxygen, which is responsible for the cross-linking
Riboflavin and ultraviolet (UV) A collagen cross-linking (CXL) of the cornea elicits a stiffening effect on the corneal stroma, which increases its biomechanical strength, thus enabling the arrest of the progression of the disease
Administration
Topical Ophthalmic Administration
For topical ophthalmic use only; do not inject
See Dosage for detailed instructions
Storage
The entire bulk pack should be stored at 15-25°C (59-77°F)
Minimize exposure of the syringe to light once removed from its protective packaging
For single use only; discard syringe after use
