Pulmonary & Respiratory Medicine

Longitudinal Follow-Up Data on Cotrimoxazole Treatment in Idiopathic Pulmonary Fibrosis and Fibrotic Non-Specific Interstitial Pneumonia

Abstract

Veronica Varney*, Helen Parnell1, Ginny Quirke, Siva Ratnatheepan, David Salisbury, Ford Brian and Alaa Witwit

Introduction: Studies suggest that cotrimoxazole may have use in patients with idiopathic pulmonary fibrosis
(IPF). We present longitudinal data from our current on-going study, looking at safety and stability of lung function,
oxygen saturations and walking tests out to 6 years.
Methods: Randomization was (double-blind) to cotrimoxazole or placebo for 12 weeks in patients who desaturate
<90% on a shuttle walking test (SWT). At 12 weeks all commence active treatment with out-of-study follow-up and
continued measurement of FVC (forced vital capacity), oxygen saturations and SWT. Data is presented on the first
53 patients.
Results: Tolerance to study drugs was good. Lab based Lung function at 1 year showed significant improvement
from individual baseline entry values for total lung capacity (+600 mls, p=0.0025), residual volume (+723 mls,
p=0.0004) and functional residual capacity (+528 mls, p=0.005). Absolute FVC (+0.5%), vital capacity (+1.5%) and
transfer factor TLCO (-2.0%) showed no significant change, remaining stable at 1 year.
Arterial PO2, SWT and oxygen saturations improved at 12 weeks along with MRC dyspnoea scores. The SGHQIPF
symptom scores improved at 1 year. Mixed effects analyses have shown that relative FVC levels are associated
with a decline by 0.005litres (0.002-0.009) per month on average, Oxygen saturations on air decrease by 0.06%
(0.03-0.09) per month and SWT by 2.3metres (1.10-3.48) per month.
Conclusion: Cotrimoxazole was well tolerated. Total lung capacity improved by a mean of + 10.7% at 1
year along with residual volume +25.6%. Symptom scores significantly improved but there was no reduction in
radiographic changes. This data has fulfilled 2 of the 3 required criteria by the ATS/ERS statement (2000) for a
favourable response. Cotrimoxazole may be a useful alternative in patients intolerant of the anti-fibrotic drugs.