Concomitant medication burden may impact tolerability of antifibrotic therapy in IPF

Concomitant medication burden is associated with antifibrotic medication intolerance among patients with idiopathic pulmonary fibrosis, according to research published in Annals of the American Thoracic Society.

“Concomitant medication burden is a potentially modifiable risk factor for intolerability of ILD-targeted medications and poor health outcomes in this population, as it is also a composite surrogate for the number and severity of comorbidities, although this has not been evaluated,” Yet H. Khor, MD, interstitial lung disease specialist at Austin Health, Monash University and the University of Melbourne in Australia, and colleagues wrote. “Although medication burden is often assessed using simple medication count and total daily pill burden, focusing on the number of medications may be an inadequate reflection of medication complexity and overall burden.”

Researchers analyzed 645 patients with IPF (mean age, 69 years; 76% men) who received nintedanib (Ofev, Boehringer Ingelheim) or pirfenidone and 1,255 patients with non-IPF interstitial lung disease (mean age, 59 years; 37% men) who received azathioprine or mycophenolate, all of whom were identified from two Australian and Canadian registries. Concomitant medication burden was assessed using medication count, polypharmacy and the medication regimen complexity index.

At 6 months and 1 year after initiation of ILD-targeted medication, researchers assessed medication intolerance and discontinuation. Medication intolerance was defined as dose reduction, temporary dose interruption or permanent drug discontinuation.

In the patients with IPF, 58% received nintedanib and 42% received pirfenidone as the initial antifibrotic medication. In those with non-IPF ILD, 31% received azathioprine and 69% received mycophenolate. At baseline, patients in both cohorts were taking a median of five concomitant medications.

Forty-three percent of patients with IPF experienced adverse reactions that led to antifibrotic medication intolerance within 6 months.

High baseline concomitant medication burden was consistently associated with antifibrotic medication count (P = .005), polypharmacy (P = .006) and medication regimen complexity index (P = .004).

Patients with non-IPF ILD also had a lower medication intolerance of 18%, but baseline concomitant medication burden was not independently associated with permanent discontinuation of antifibrotic (29%) and immunosuppressive medications (20%) at 1 year in these patients.

The medication regimen complexity index was the only concomitant medication burden measure linked to transplant-free survival among both patient groups (P < .01 for both), which also improved prognostication beyond common clinical factors and the ILD-GAP index (P < .001 for both).

“Assessment of concomitant medication burden before the commencement of antifibrotic medications can help identify patients at risk of therapy intolerability who may benefit from early follow-up and additional support,” the researchers wrote. “It is essential to further evaluate strategies that may reduce the impact of medication burden on health outcomes and quality of life in patients with ILD.”