Background

Due to high variability and rapid life cycle, influenza virus is able to develop drug resistance against direct acting antivirals. Development of novel virus-inhibiting drugs is therefore important goal. Previously, we identified camphor derivative, camphecene, as an effective anti-influenza compound. In the present study we optimize the regimen of its application to avoid high sub-toxic concentrations.

Methods

The protective activity of camphecene was assessed on the model of lethal pneumonia of mice caused by influenza viruses. Camphecene was administered either once a day or four times a day, alone or in combination with Tamiflu. Mortality and viral titer in the lungs was studied. Pharmacokinetics of camphecene was studied in rabbits.

Results

We have demonstrated that camphecene, being used every six hours at a dose of 7.5 mg/kg/day, results in anti-viral effect that was statistically equal to the effect of 100 mg/kg/day once a day, i.e. the same effect was achieved by thirteen-times lower daily dose of the drug. This effect was manifested in decrease of mortality and decrease of virus’ titer in the lungs. The studies of pharmacokinetics of camphecene have demonstrated that it does not accumulate in blood plasma and that its multiple applications with dosage interval of 65 min is safe. In addition, the results of the study demonstrate also that camphecene possesses additive effect with Tamiflu allowing to decrease the dose of the latter.

Conclusion

The results suggest that due to safety and efficacy, camphecene can be further developed as potential anti-influenza remedy.