Effect of topical naltrexone 0.3% on corneal sensitivity and tear parameters in normal brachycephalic dogs

Abstract

Naltrexone 0.3% is well tolerated and safe when applied topically to the eye once daily. Naltrexone 0.3% did not show any significant effects on corneal parameters as measured in this study. At once, daily dosing NTX is systemically absorbed; however, the degree of systemic absorption is not likely to be clinically significant.

Effect of once daily topical 0.3% naltrexone on tear parameters and corneal sensitivity in dogs with uncontrolled keratoconjunctivitis sicca: a double‐masked randomized placebo‐controlled clinical trial

“…Both the diabetic rat and normal rat studies had dosing frequencies of 4 applications over a 10‐h period per day. Pharmacokinetic evaluation of the topical 0.3% NTX seems to suggest clearance by at least 24 h after once daily topical administration . No reported side effects from the topical administration were noted in this study or the study in normal brachycephalic dogs; however, caution may be required in dogs receiving opioids .…”

“…Pharmacokinetic evaluation of the topical 0.3% NTX seems to suggest clearance by at least 24 h after once daily topical administration . No reported side effects from the topical administration were noted in this study or the study in normal brachycephalic dogs; however, caution may be required in dogs receiving opioids . If a higher concentration or more frequent administration were to be given, further study into its pharmacokinetics is warranted.…”

“…The applied eye drops were then discontinued at week 4 and a repeat of the three diagnostics were performed at week 5. Cochet–Bonnet esthesiometry was performed on week 4 to compare to week 0 values as previously described . Given the temperament of some study subjects, Cochet–Bonnet esthesiometry was performed after STT1, TFBUT, and IOP to ensure proper assessment of the main points of interest of the study, namely tear production.…”

“…Naltrexone (NTX) is an opioid antagonist which has shown some promise for increasing tear production and corneal sensitivity in diabetic rats . A previous study by Arnold et al . evaluated whether topical use could increase corneal sensitivity in brachycephalic dogs.…”

A retrospective survey of ocular abnormalities in pugs: 130 cases

“…The high prevalence of low TFBUT values in pugs is corroborated by several other studies (Arnold et al . ; Labelle et al . ).…”