Zylet vs Tobradex

Zylet (loteprednol/tobramycin) is a combination steroid/antibiotic eye drop like Tobradex. After difficulties with insurance reimbursement and an ultimate switch to tobramycin/dexamethasone, the question came up as to whether or not there was a substantial difference in efficacy/safety between these two products. I have summarized my findings from multiple trials below:

Title	Study Type	Results
Comparison of the safety and efficacy of loteprednol 0.5%/tobramycin 0.3% with dexamethasone 0.1%/tobramycin 0.3% in the treatment of blepharokeratoconjunctivitis2	Multicenter, randomized, investigator-masked, parallel group study	·  Loteprednol/tobramycin determined to be non-inferior to DM/T      ·   Pts treated with DM/T experienced a significant increase in intraocular pressure compared to those treated with LE/T
A randomized controlled trial comparing dexamethasone with loteprednol etabonate on postoperative photorefractive keractectomy3	Prospective, randomized, double-masked controlled study	·  Corneal epithelium healed one day sooner in patients treated with loteprednol       · 1/16 patients treated with lot. experienced significant increase in IOP (>5mmHg) whereas 3/16 patients treated with DM did.
Tolerability of loteprednol/tobramycin versus dexamethasone/tobramycin in healthy volunteers: results of a 4-week, randomized, double-masked, parallel-group study4	Multicenter, randomized, double-masked, parallel-group study	·  Loteprednol/tobramycin satisfied non-inferiority requirements       ·  Significant, but small, differences favored loteprednol for comfort/tolerability (tears, burning, itching, etc)
Effects of loteprednol/tobramycin versus dexamethasone/tobramycin on intraocular pressure in healthy volunteers.5	Randomized,       double-masked, multicenter, parallel-group trial	·  Significantly lower number of patients experienced IOP increase > 10mmHg when treated with loteprednol/tobramycin compared to tobramycin/dexamethasone (1.95% vs 7.48%)      · Both medications well tolerated

Conclusions

Zylet appears to be non-inferior to Tobradex. There may be a small difference in tolerability favoring Zylet, but both medications were well-tolerated overall.  However, tobramycin/dexamethasone was significantly more likely to cause significant increases in intraocular pressure in multiple studies, which may make Zylet a more favorable option for patients for whom intraocular pressure is a concern (glaucoma, etc).

References

1.   1.  White EM, Macy JI, Bateman KM, Comstock TL. Comparison of the safety and efficacy of loteprednol 0.5%/tobramycin 0.3% with dexamethasone 0.1%/tobramycin 0.3% in the treatment of blepharokeratoconjunctivitis. Curr Med Res Opin. 2008;24:(1)287-96. [pubmed]

3.   2. Thanathanee O, Sriphon P, Anutarapongpan O, et al. A randomized controlled trial comparing dexamethasone with loteprednol etabonate on postoperative photorefractive keratectomy. J Ocul Pharmacol Ther. 2015;31:(3)165-8. [pubmed]

4.   3. Bartlett JD, Holland EJ, Usner DW, Paterno MR, Comstock TL. Tolerability of loteprednol/tobramycin versus dexamethasone/tobramycin in healthy volunteers: results of a 4-week, randomized, double-masked, parallel-group study. Curr Med Res Opin. 2008;24:(8)2219-27. [pubmed]

5.   4. Holland EJ, Bartlett JD, Paterno MR, Usner DW, Comstock TL. Effects of loteprednol/tobramycin versus dexamethasone/tobramycin on intraocular pressure in healthy volunteers. Cornea. 2008;27:(1)50-5. [pubmed]