Acute hypoxic respiratory failure due to Lenalidomide-induced interstitial pneumonitis in a patient with multiple myeloma.

BACKGROUND

Patients with multiple myeloma are immunosuppressed due to both the disease itself and immunosuppressive therapies. Thus, when presenting with respiratory failure and pulmonary opacities, pneumonia must be considered. However, while rare, immunomodulating medications used in the treatment of multiple myeloma can also cause potentially life-threatening respiratory failure, a distinction which has important treatment implications.

CASE PRESENTATION

An 80-year-old male with recently diagnosed multiple myeloma undergoing treatment with lenalidomide and daratumumab presented with acute, rapidly progressive hypoxic respiratory failure ultimately requiring intubation and mechanical ventilatory support. Imaging revealed bilateral pulmonary opacities, however infectious workup was negative, and he was ultimately diagnosed with lenalidomide-induced interstitial pneumonitis, a rare but serious adverse effect of this medication. He was treated with drug discontinuation and methylprednisolone, and quickly recovered.

CONCLUSION

Lenalidomide is an immunomodulating medication used in the treatment of multiple myeloma, and is associated with rare but serious cases of drug-induced interstitial pneumonitis. Thus, if a patient receiving lenalidomide develops shortness of breath and/or hypoxia, drug-induced pneumonitis must be on the differential. Permanent drug discontinuation with or without corticosteroids is the mainstay of treatment, and patients are often able to fully recover, underscoring the need for early recognition of this condition.