| Options for therapy | Diagnosis of definite IPF | Diagnosis of probable IPF | Diagnosis of fibrotic NSIP with IPF profile | ||
| Requires: | Requires: | Requires: | |||
| 1. Clinical features consistent with IPF | 1. Clinical features consistent with IPF | 1. Clinical features consistent with IPF | |||
| 2. Diagnostic HRCT scan or UIP on biopsy and HRCT scan consistent with IPF | 2. HRCT scan consistent with but not diagnostic of IPF3. Absence of lung biopsy | 2. HRCT scan consistent with but not diagnostic of IPF3. Histological pattern of fibrotic NSIP | |||
| No specific drug therapy: patient co-morbidity, concerns of side effects, patient wishes, mild disease without evidence of progression, etc may preclude specific drug therapy | No specific therapy may be appropriate for some patients [D] | No specific therapy may be appropriate for some patients [D] | No specific therapy may be appropriate for some patients [D] | ||
| Trial of high-dose steroid monotherapy (eg, 0.5–1 mg/kg for up to 3 months followed by dose reduction). Maintenance dose and length of treatment dependent on objective response (improvement or lack of progression) in lung function and/or radiology | No – strong recommendation [C] | No – strong recommendation [D] | No –weak recommendation [D] | ||
| Prednisolone and azathioprine as per ATS/ERS guidelines (prednisolone 0.5 mg/kg/day tapering over 3 months to 0.125 mg/kg/day and azathioprine 2–3 mg/kg/day to a a maximum of 150 mg/day) | Not recommended without N-acetylcysteine (NAC) pending further evidence | ||||
| Prednisolone and azathioprine as per ATS guidelines + NAC 600 mg three times daily* | Yes – weak recommendation [C] | Yes – weak recommendation [D] | Yes – weak recommendation [D] | ||
| Interferon-γ-1b | Not recommended pending further evidence | ||||
| Pirfenidone | |||||
| Bosentan | |||||
| Other therapeutic options | There are insufficient data to make evidence-based recommendations on therapeutic regimes other than those described above. Combination or single drug regimes that include low dose prednisolone (20 mg/day or less) and/or azathioprine and/or NAC may be better tolerated than the suggested alternatives but are without evidence base. | ||||
| When to start drug therapy if decision to treat is made: | There are no data on which to make evidence-based recommendations for when to start treatment. It is therefore suggested that treatment, if started, could equally reasonably be initiated at diagnosis or following objective evidence of disease progression or in moderate/severe disease [D] | ||||
*Currently unlicensed for this indication in the UK.