Teriparatide (Forteo, Forsteo)

Safety Summary

In the two principal osteoporosis trials (N=1382), the overall safety profile was favorable with 7% discontinuation due to adverse events in the teriparatide group vs 6% in placebo. All-cause mortality was 1% in both groups. Serious adverse events occurred in 16% (teriparatide) vs 19% (placebo). The most clinically significant adverse effects are: (1) Transient hypercalcemia occurring 4-6 hours post-dose (11% women, 6% men had at least one episode; returns to baseline by 16-24 hours; consecutive confirmed elevations in only 3% of women and 1% of men; serum calcium peaked at ~4.25 h post-dose and remained below 11 mg/dL in >99% of women per visit) -- FDA label Section 6.1; PMC2978887; (2) Orthostatic hypotension occurring mainly with initial doses, typically within 4 hours, resolving within minutes to hours -- FDA label Section 5.4; (3) The rodent osteosarcoma signal that prompted a 2-year lifetime treatment duration limit, though a 15-year post-marketing surveillance study and two large US claims-based surveillance studies (379,283 and 153,316 users) found 3 and 0 osteosarcoma cases respectively, suggesting similar risk to general population (PMC8037129; FDA label Section 6.2). The boxed warning was revised (narrowed) in 2020. In the glucocorticoid-induced osteoporosis trial (n=428), nausea was more common (14% vs 7% active control). Post-marketing pharmacovigilance (FAERS analysis) confirmed the known safety profile with nausea and GI disorders as the most commonly reported events (.3389/fphar.2024.1391356 via). Immunogenicity: antibodies to teriparatide detected in ~3% of women; no impact on efficacy or safety reported (FDA label). No CYP-mediated drug interactions. Real-world reports from patient forums confirm transient nausea, bone/joint pain, dizziness, and fatigue as the most common complaints (; Mayo Clinic Connect; HealthUnlocked via).