Teriparatide and parathyroid hormone Parathyroid hormone is naturally produced to regulate calcium levels. Teriparatide is very similar. Learn how they’re used, risks and side-effects. Tocilizumab Tocilizumab is a biological therapy for rheumatoid arthritis and juvenile idiopathic arthritis (JIA). Learn how it’s used, risks and side-effects. Tofacitinib Tofacitinib is used to treat rheumatoid arthritis and psoriatic arthritis. Find out how long it takes to work, how it’s taken and possible side effects.