Teriparatide-associated calciphylaxis: a case series

Calciphylaxis is a rare and potentially fatal small-vessel occlusive disease in which the tunica media becomes calcified, endothelial cells proliferate, and the tunica intima becomes thickened and fibrotic. Calciphylaxis typically occurs in the setting of end-stage renal disease with secondary hyperparathyroidism and elevated calcium-phosphorus product. The estimated incidence of calciphylaxis in dialysis or kidney transplant patients is 1 to 4%; however, the incidence of non-uremic calciphylaxis is unknown. We assessed postmarketing adverse event reports to further characterize cases of calciphylaxis associated with teriparatide. We searched for cases of teriparatide-associated calciphylaxis in the literature (EMBASE, PubMed) and those reported to FDA, including the FDA Adverse Event Reporting System, through March 31, 2021. We included calciphylaxis cases following teriparatide exposure of < 2 years. Twelve cases described teriparatide-associated calciphylaxis. The median age was 81 (range 47-86) years. Eleven cases reported confirmatory biopsy and/or imaging. The median time-to-onset of calciphylaxis following teriparatide initiation was 3.5 (range 1-20) months. Three cases reported hospitalization, of which one resulted in death due to progression of the lesions. All cases had multiple risk factors (mean (SD), 4.5 (1.0)) including concomitant medications associated with calciphylaxis (12), female sex (11), and/or underlying autoimmune disease or other inflammatory disorder (10). We believe that exposure to teriparatide, coupled with underlying risk factors, may have triggered new-onset calciphylaxis. Expedited diagnosis and management by a clinician are important because calciphylaxis may be life-threatening and early intervention may improve outcomes.