April 2021

Efficacy of Intranasal Theophylline in Hyposmic Patients after a Viral-Type Infection

We have evaluated and treated 54 patients who exhibited hyposmia (smell loss) after a viral-type infection. To do so we have measured several parameters of smell function before and after treatment with intranasal theophylline, 40 μg instilled intranasally in each nostril once daily. We measured responses to four odorants, pyridine, nitrobenzene, thiophene and amyl acetate.

Compared to before treatment, after 2-4 months of treatment there was significant improvement in detection thresholds, recognition thresholds and magnitude estimation for each odorant. With respect to hedonics after treatment, pyridine was appreciated as significantly more unpleasant as was thiophene.

These results indicate that intranasal theophylline is an efficacious treatment for restoring smell function in patients with hyposmia which occurred after a viral-type infection.