Abstract
Objectives - The aim of the study was to identify any unexpected clinical events associated with starting the new CFC-free formulation of Atrovent® MDI in general practice in England.
Methods - An active surveillance cohort study was conducted with a focus on selected clinical events, including respiratory symptoms, in past users of Atrovent® CFC MDI (‘switchers’) and Atrovent® naïve users. Incidence density rate ratios (with 99% confidence intervals) for events occurring in the first three months of exposure (risk period-ID1-3) compared to three months prior to starting treatment (reference period-IDR) were calculated.
Results - The cohort consisted of 13,211 patients (median age 70 years, 50.1% female; 63.5% prior users of Atrovent® CFC MDI (‘switchers’)). Common respiratory events occurred at higher rates after starting treatment than before for switchers e.g Lower respiratory tract infection (LRTI) [ID1/IDR=1.45 (99%CI: 1.17, 1.81)] and worsening asthma [ID1/IDR= 1.58 (99%CI: 1.00, 2.51)]. Of these events only LRTI was significant for Atrovent® naïve patients [ID1/IDR= 1.42 (99%CI: 1.04, 1.95)].
Conclusions - The results of this study suggest effect modification of risk as a result of prior Atrovent® CFC MDI use. Overall, Atrovent® CFC-free MDI appeared to be reasonably well tolerated in the immediate post-marketing period and the safety profile appeared similar to that of the CFC formulation.
Methods - An active surveillance cohort study was conducted with a focus on selected clinical events, including respiratory symptoms, in past users of Atrovent® CFC MDI (‘switchers’) and Atrovent® naïve users. Incidence density rate ratios (with 99% confidence intervals) for events occurring in the first three months of exposure (risk period-ID1-3) compared to three months prior to starting treatment (reference period-IDR) were calculated.
Results - The cohort consisted of 13,211 patients (median age 70 years, 50.1% female; 63.5% prior users of Atrovent® CFC MDI (‘switchers’)). Common respiratory events occurred at higher rates after starting treatment than before for switchers e.g Lower respiratory tract infection (LRTI) [ID1/IDR=1.45 (99%CI: 1.17, 1.81)] and worsening asthma [ID1/IDR= 1.58 (99%CI: 1.00, 2.51)]. Of these events only LRTI was significant for Atrovent® naïve patients [ID1/IDR= 1.42 (99%CI: 1.04, 1.95)].
Conclusions - The results of this study suggest effect modification of risk as a result of prior Atrovent® CFC MDI use. Overall, Atrovent® CFC-free MDI appeared to be reasonably well tolerated in the immediate post-marketing period and the safety profile appeared similar to that of the CFC formulation.
| Original language | English |
|---|---|
| Journal | International Journal of Pharmacy Practice |
| Early online date | 9 Oct 2017 |
| DOIs | |
| Publication status | Early online - 9 Oct 2017 |