ROCHESTER, MINN—Intranasal application of amphotericin B improved symptoms of chronic rhinosinusitis (CRS) in 75% of patients in a pilot study, and it resulted in few side effects.[1] With few options available to control CRS, this surprising finding could change disease management choices in the future. Currently, glucocorticoids are often prescribed because the disorder includes sinus mucosal inflammation. However, their long-term use is associated with adverse side effects.

What prompted Jens Ponikau, MD, and colleagues to use an antifungal to combat CRS? Two other Mayo Clinic findings. The first confirmed the presence of both sinus tissue eosinophilia and fungal organisms in the sinus mucus of 96% of patients with CRS.[2] More recently, Hirohito Kita, MD, another study author, discovered that exposure of mononuclear cells to fungal antigens in vitro led to the production of high levels of interleukin 5 (IL-5) and IL-13 in patients with CRS. This suggests that an immunologic response to certain intranasal fungi may play a part in the pathophysiology of CRS.

Thus, investigators enrolled 51 patients with CRS resistant to treatment to test the antifungal drug. The diagnosis of CRS was based on patient history, endoscopic examination, and computed tomography (CT) scans. Symptoms had to have been present for at least three months and had to include nasal obstruction, blockage, or discharge; facial pain, pressure, congestion, or fullness; and hyposmia or anosmia. Inflammation of the nasal mucosa was confirmed with endoscopy.

Patients were given amphotericin B for three months at a dosage of 20 mL of the solution per nostril twice daily. Treatment efficacy was measured using subjective assessment of symptoms by the patient and objective measurement of endoscopic changes.

According to patient reports, about 75% (38/51) had an improvement in both nasal obstruction and nasal discharge and 25% showed no improvement; no one reported that symptoms worsened. About half (25) of the patients reported that their symptoms were completely gone after treatment. Patients generally showed improvement after one month to three months.

Follow-up was done for at least three months. The intranasal administration of amphotericin B was linked with only one reported side effect: a burning on application that occurred in 20% of patients. The sensation was not severe enough to cause anyone to withdraw from the study.

Endoscopic findings confirmed patient reports. The number of patients who had polyps filling the nasal cavity decreased from 36 to eight, and 18 patients showed no evidence of disease on follow-up endoscopy. There was no evidence of improvement in 13 patients, however.

Possible weaknesses of the study include the lack of a placebo group and the fact that inflammatory parameters in the sinus mucus were not analyzed. Thus, double-blind placebo-controlled studies are necessary to further prove the efficacy of the treatment, as well as to establish optimal dosing and clarify the role of fungal organisms in CRS.

—Lisa Pallatroni