Objective To determine whether intranasal theophylline methylpropyl paraben can correct hyposmia and hypogeusia.
Design We performed an open-label pilot study in patients with hyposmia and hypogeusia under the following 3 conditions: (1) before treatment, (2) after oral theophylline anhydrous treatment, and (3) after intranasal theophylline treatment. Under each condition, we performed subjective evaluations of taste and smell functions, quantitative measurements of taste (gustometry) and smell (olfactometry), and measurements of serum theophylline level and body weight.
Setting The Taste and Smell Clinic in Washington, DC.
Patients Ten patients with hyposmia and hypogeusia clinically related to the effects of viral illness, allergic rhinitis, traumatic brain injury, congenital hyposmia, and other chronic disease processes were selected.
Interventions Oral theophylline anhydrous, 200 to 800 mg/d for 2 to 12 months, was administered to each patient. This treatment was discontinued for 3 weeks to 4 months when intranasal theophylline methylpropyl paraben, 20 μg/d in each naris, was administered for 4 weeks.
Main Outcome Measures At termination of each condition, taste and smell function was determined subjectively, by means of gustometry and olfactometry, with measurement of serum theophylline levels and body weight.
Results Oral theophylline treatment improved taste and smell acuity in 6 patients after 2 to 12 months of treatment. Intranasal theophylline treatment improved taste and smell acuity in 8 patients after 4 weeks, with improvement greater than after oral administration. No adverse effects accompanied intranasal drug use. Body weight increased with each treatment but was greater after intranasal than after oral administration.
Conclusions Intranasal theophylline treatment is safer and more effective in improving hyposmia and hypogeusia than oral theophylline anhydrous treatment.