S. Morris et al., AN EVALUATION OF NASAL RESPONSE FOLLOWING DIFFERENT TREATMENT REGIMESOF OXYMETAZOLINE WITH REFERENCE TO REBOUND CONGESTION, American journal of rhinology, 11(2), 1997, pp. 109-115
This was a randomized double-blind vehicle controlled study aimed at i
nvestigating the effects on nasal function of 7 days treatment with th
e topical decongestant oxymetazoline (0.05% w/v). Fifty healthy volunt
eers took part in the study and these were randomly allocated to three
treatment groups (i) daily oxymetazoline (b.i.d. 150 mu l per nostril
) (ii) intermittent oxymetazoline, with oxymetazoline being substitute
d for vehicle at the morning doses on days 1, 3, and 7; and (iii) dail
y vehicle (b.i.d. 150 mu l per nostril). The nasal airway was assessed
by measurement of nasal airway resistance (NAR) using posterior rhino
manometry, subjective scaling of nasal patency by means of a visual an
alogue scale (VAS), and clinical visual examination. On days 1, 2, 3,
and 7, NAR and VAS measurements were obtained before the morning dose
and up to 6 hours after dosing; clinical visual examinations were also
performed before dosing on these days. NAR and VAS measurements were
also made following withdrawal of treatment on Days 8 and 9. Nonparame
tric analysis of the results showed that therapeutic tolerance to oxym
etazoline did not develop over the 7-day treatment period, and visual
examination of the nasal mucosa failed to find significant evidence of
rhinitis. Evidence of rebound nasal congestion was found following 3
days of oxymetazoline treatment, with baseline NAR within the daily an
d intermittent oxymetazoline groups being significantly greater on Day
3 compared to Day 1 (p < 0.05). However, there was a trend toward inc
reasing baseline NAR in the vehicle group over the course of the study
, suggesting that the vehicle may have contributed to the rebound cong
estion. Following the withdrawal of treatments, only the intermittent
oxymetazoline group had significantly higher NAR on Days 8 and 9 compa
red to Day 1 (p < 0.05). Subjective VAS measurements generally followe
d trends in NAR.