Idiopathic Pulmonary Fibrosis: What Can a General Practitioner Do?
When a previously healthy patient becomes breathless, it's never good news. Among the particularly serious issues that breathlessness can signal is idiopathic pulmonary fibrosis (IPF). However, its prognosis no longer has to be as unfavorable as before, especially if diagnosed early.
The Key is Early Detection − How to Assist?
Idiopathic pulmonary fibrosis is the most common interstitial lung disease, and even though its course is variable, exacerbations are not rare. During exacerbations, the patient typically experiences a decline in lung function, manifested by breathlessness, reduced exercise tolerance, and generally lower quality of life. In these situations, hospitalization with a high risk of a fatal outcome sometimes cannot be avoided.
It's also one of the most common indications for lung transplantation. Before the advent of effective treatments, the median survival for patients at the time of diagnosis was 3–5 years. Early detection of the disease is thus a critical factor, and for it, conducting HRCT scanning is essential, without which the diagnosis cannot be made. Spirometry can remain normal for a long time, and a chest X-ray cannot identify this disease.
Are We Ready for Treatment?
Until 2014, care for these patients was limited to immunosuppressants and supportive treatment, but the PANTHER-IPF study showed that the popular combination of prednisone, azathioprine, and N-acetylcysteine was ineffective and even increased the risk of hospitalization and death. Immunosuppressants are no longer administered for IPF, except for corticosteroids in the case of acute breathlessness. Acetylcysteine by itself, according to the cited study, practically has no effect on IPF.
The clear goal was to identify key signaling pathways that promote the development of idiopathic pulmonary fibrosis and target them pharmacologically. Antifibrotic drugs, pirfenidone and nintedanib, approved for IPF treatment in 2011 and 2015 respectively, most likely have this capability.
Nintedanib is an intracellular inhibitor of various tyrosine kinases, including the fibroblast growth factor receptor, vascular endothelial growth factor receptor, and others. It demonstrated its antifibrotic properties in animal models. The exact mechanism of action of pirfenidone is not entirely known, but it likely exerts both antifibrotic and anti-inflammatory properties. Both drugs have shown clinical benefits in clinical trials for IPF. Considering the prognosis of untreated IPF, it is clear that therapy must begin as early as possible to provide any clinical benefit to the patient.
Therapy Risks − and How to Avoid Them?
When treating with these drugs, liver tests must be monitored because there can be rises in aminotransferases or bilirubin. Therefore, in patients with mild liver injury (Child-Pugh A), a reduced dose is recommended, and in cases of more severe damage, the drugs are not recommended at all. Otherwise, the treatment is well tolerated, with side effects depending on the specific medication; the most common for nintedanib is diarrhea, and for pirfenidone, photosensitivity reactions.
Given nintedanib's mechanism of action, arterial thromboembolic events and an increased risk of bleeding have been noted, hence it is recommended to prescribe this drug cautiously for patients with elevated cardiovascular risk and those on anticoagulants.
Part of the treatment should also include respiratory rehabilitation and smoking cessation, which is very important, although challenging at the age when these patients typically present.
Caring for Patients with IPF
In daily care, cooperation focused on good adherence to treatment and limiting interactions or undesired interferences with the treatment is crucial. Adherence generally depends on the dosing schedule, side effects, and motivation for diligence. Clinical pharmacists can significantly aid in enhancing adherence by optimizing pharmacotherapy to prevent interactions. The regimen also needs optimization not only for IPF but also for possible comorbidities such as tobacco dependence, COPD, or gastroesophageal reflux (GER).
Education and emotional support are crucial components of care for patients with interstitial lung fibrosis. Patients often try to find information online, but the content they find is rarely up-to-date and can cause unnecessary anxiety. It's important to recommend suitable sources.
If it becomes necessary to proceed to palliative care, oxygen therapy, or the administration of medications indicated for terminal states, it is essential to strictly follow the patient's needs.
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Source: Pleasants R., Tighe R. M. Management of idiopathic pulmonary fibrosis. Ann Pharmacother 2019; 53 (12): 1238–1248, doi: 10.1177/1060028019862497.
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