Vyzulta, otherwise known as latanoprostene bunod, is the latest glaucoma innovation since the introduction of prostaglandin analogues.
The structure of Vyzulta is interesting because it is a prodrug medication which is hydrolyzed into two components: latanoprost acid (prostaglandin - you may recognize this as Xalatan from Pfizer) and butanediol mononitrate.
Latanoprost acid increases aqueous humour flow via uveoscleral pathway.
Butanediol mononitrate is hypothesized to be broken down further into nitric oxide, relaxing the trabecular meshwork and increasing aqueous humour flow.
With two mechanisms of action, greater reductions of intraocular pressure could be achieved. This is the theoretical advantage that Bausch and Lomb use to market Vyzulta.
Role in Therapy
Vyzulta can be considered as one of the first line options for glaucoma along with prostaglandin analogues. Its additional mechanism of action using nitric oxide may be attractive; however, word of caution, nitric oxide was discovered in vitro but not confirmed in vivo (so we don’t know if there is nitric oxide at all in ocular tissues!). Furthermore, its benefit has not been clearly shown because the Phase 3 non-inferiority trials compared once daily Vyzulta versus twice daily beta blocker timolol 0.5%. Current Canadian glaucoma guidelines would recommend prostaglandins as first line comparators.
Vyzulta is administered once daily in the evening. Remember to space apart from other eye drops by 5 minutes and wait 15 minutes before inserting contact lenses.
Adverse effects are very similar to that of Xalatan, including nasopharyngitis, eyelash lengthening, iris or eyelid colour change, ocular redness, irritation and pain.
Vyzulta should be kept in the fridge until usage, then it can be stored at room temperature for 8 weeks.