D3.17 - Outcomes of Anti-Tuberculosis Drug Reintroduction Following Adverse Drug Reactions among Adult Patients at a Tertiary Hospital in the Philippines (2022-2024)

Tuberculosis (TB) patients who experience adverse drug reactions (ADRs) often lead to treatment interruption. This may cause drug resistance and poor patient outcome despite available treatment. Reintroduction of TB medications can be done by rechallenge, desensitization, treating through if with mild symptoms or introduction to second line treatment for severe reactions. Currently, we have limited local data describing outcomes of patients who suffer ADRs from TB medications.

A retrospective cohort study was done looking at 215 adult patients diagnosed with TB who developed ADRs to the first line treatment and was referred to the TB – DOTS or the Section of Allergy and Immunology. Demographic data, frequent reactions and implicated medications was obtained with the corresponding management approach and outcome. Statistical analysis was done to determine significance and association.

Of the 215 patients, majority were male (54.4%) with median age at 45 years old. Most patients are newly diagnosed (78.6%) pulmonary TB cases (80.9%). The most frequently encountered ADRs are mild cutaneous reactions (41.9%) followed by hepatotoxicity (32.6%). Standard first line quadruple therapy combination of isoniazid, rifampicin, pyrazinamide and ethambutol was the most frequently implicated (61.4%). Rechallenge (60.9%) was frequently applied, followed by shifting to second line treatment (20.5%), then treat trough strategy (10.7%) and with few cases of desensitization (3.3%). Overall, most patients were able to complete their treatment (81.4%) with 10.2% mortality and 7.4% loss to follow-up. There was no statistical significance among personal history of atopy, history of previous drug allergy and lifestyle factors such as smoking. Among the comorbidities, chronic kidney disease (CKD) was the only statistically significant.

Most patients were able to complete their treatment despite experiencing ADRs to first line treatment once reintroduction strategies were employed. Choosing the appropriate strategy for reintroduction should still be individualized. Early recognition of ADRs and possible contributing factors such as co-morbidities are essential for better outcomes.