Cost of managing severe cutaneous adverse drug reactions to first-line tuberculosis therapy in South Africa

Objective To compare the cost of managing treatment-limiting cutaneous adverse drug reactions (CADRs) to first-line anti-tuberculosis drugs to an alternative strategy of immediate treatment initiation using second-line drugs in a South African setting. Methods Clinical and cost data were retrospectively collected from patients presenting with a first-line anti-tuberculosis therapy-associated CADR. Costs (2016 US$) were estimated using an ingredient's approach from a healthcare provider perspective. The per-patient and total cost of drug rechallenge, the current management strategy for severe CADR, was calculated. Alternative strategies involving second-line treatment were derived from literature and expert clinical advice. Results Drug rechallenge costs US $5831 (95% CI: 5134-6527) per patient. Hospitalisation accounted for 62% of this cost. Alternative CADR management strategies using regimens containing rifabutin, bedaquiline and/or delamanid cost 44%-55% less than drug rechallenge (US $2651-US $3276/patient). In univariate sensitivity analyses, drug rechallenge and alternative strategies were most sensitive to hospitalisation and tuberculosis drug costs, respectively. Conclusion Cutaneous adverse drug reactions to anti-tuberculosis treatment represent a significant economic burden. An alternate strategy of outpatient-initiated second-line therapy is economically feasible but requires clinical validation to assess effectiveness.