Tuberculosis (TB) remains one of the world’s deadliest infectious diseases, with over 3,300 deaths and more than 29,000 new cases daily. While much attention focuses on the disease itself, a critical pharmacovigilance concern involves two interconnected safety issues: drug-induced TB (the development of active TB triggered by immunosuppressive medications) and adverse drug reactions (ADRs) from anti-TB medications.
This comprehensive review examines the mechanisms, risk factors, and clinical presentations of drug-induced TB, with detailed analysis of the safety profiles of first-line and second-line anti-TB drugs. Drawing on data from the FDA Adverse Event Reporting System (FAERS), WHO global TB reports, and regulatory communications from EMA and other authorities, this article provides evidence-based guidance for healthcare professionals managing patients at risk for drug-induced TB and those receiving TB treatment. The review concludes with WHO’s latest recommendations for new diagnostic tools released on World TB Day 2026, marking a transformative step toward ending the TB epidemic.
1. Introduction: The Dual Pharmacovigilance Challenge of Tuberculosis
Tuberculosis remains a global health emergency. Since 2000, global efforts have saved an estimated 83 million lives, yet the disease continues to claim over 3,300 lives daily. World TB Day 2026, observed under the theme “Yes! We Can End TB: Led by Countries, Powered by People,” represents both a call to action and a recognition that ending TB requires not only new tools but also vigilant monitoring of existing treatments.
From a pharmacovigilance perspective, TB presents two distinct challenges:
- Drug-Induced TB: Immunosuppressive medications—particularly biologics used in autoimmune diseases—can reactivate latent TB infection or predispose to new active TB.
- Anti-TB Drug Adverse Reactions: First-line and second-line anti-TB drugs carry significant toxicity profiles that can lead to treatment discontinuation, drug resistance, and patient harm.
This review addresses both challenges, providing a comprehensive safety analysis for healthcare professionals managing patients across these intersecting domains.
2. Drug-Induced Tuberculosis: Mechanisms and Risk Factors
2.1 Definition and Epidemiology
Drug-induced TB refers to the development of active tuberculosis disease triggered by medications that suppress the immune system, thereby reactivating latent TB infection (LTBI) or facilitating progression from recent infection to active disease. This phenomenon is most commonly associated with tumor necrosis factor-alpha (TNF-α) inhibitors, but other immunosuppressive agents also confer risk.
The global burden of drug-induced TB is substantial. A 2024 systematic review estimated that patients receiving TNF-α inhibitors have a 2- to 5-fold increased risk of developing active TB compared to the general population, with the highest risk occurring within the first year of treatment.
2.2 Mechanisms of Drug-Induced TB
| Mechanism | Description | Drugs Implicated |
|---|---|---|
| TNF-α Inhibition | TNF-α is critical for granuloma formation and maintenance; blocking it disrupts containment of M. tuberculosis | Infliximab, adalimumab, etanercept, certolizumab, golimumab |
| T-cell Suppression | Reduced T-cell function impairs cell-mediated immunity essential for TB control | Corticosteroids, calcineurin inhibitors, methotrexate |
| Macrophage Dysfunction | Impaired macrophage phagocytosis and killing of mycobacteria | Corticosteroids, TNF-α inhibitors |
| Granuloma Disruption | Compromise of granuloma integrity allows bacterial spread | TNF-α inhibitors |
2.3 Drugs Most Commonly Associated with TB Reactivation
2.3.1 TNF-α Inhibitors
The association between TNF-α inhibitors and TB reactivation is well-established. A 2023 meta-analysis of observational studies reported:
| TNF-α Inhibitor | Relative Risk of Active TB (vs. General Population) |
|---|---|
| Infliximab | 4.0–6.0 |
| Adalimumab | 3.0–5.0 |
| Etanercept | 1.5–2.5 |
| Golimumab | 3.0–4.0 |
| Certolizumab | 2.5–3.5 |
Regulatory Actions:
- FDA (2008): Added black box warning to all TNF-α inhibitors regarding TB risk, requiring screening for LTBI before initiation.
- EMA (2016): Strengthened warnings and emphasized the need for continued monitoring during treatment.
2.3.2 Corticosteroids
Chronic corticosteroid use is a well-recognized risk factor for TB reactivation. A 2022 FAERS analysis identified over 1,200 reports of active TB in patients receiving systemic corticosteroids, with risk increasing with dose and duration.
Risk Thresholds:
- Prednisone equivalent ≥15 mg/day for ≥4 weeks significantly increases risk
- Inhaled corticosteroids confer minimal risk
2.3.3 Other Immunosuppressants
| Drug Class | Examples | TB Risk |
|---|---|---|
| Janus kinase (JAK) inhibitors | Tofacitinib, baricitinib, upadacitinib | Moderate (comparable to TNF-α inhibitors) |
| Calcineurin inhibitors | Tacrolimus, cyclosporine | Low to moderate (often in combination) |
| Antimetabolites | Methotrexate, azathioprine | Low (except when combined with corticosteroids) |
| mTOR inhibitors | Sirolimus, everolimus | Low |
| Anti-CD20 antibodies | Rituximab | Low (delayed onset; may occur months after therapy) |
2.4 Screening and Prevention
WHO Guidelines (2025 Update): All patients being considered for immunosuppressive therapy (especially TNF-α inhibitors) should undergo screening for LTBI, including:
- Tuberculin skin test (TST) or interferon-gamma release assay (IGRA)
- Chest X-ray (to rule out active disease)
- Evaluation for symptoms of active TB
LTBI Treatment: For patients with positive screening results, treatment for LTBI should be completed before initiating immunosuppressive therapy. Recommended regimens include:
- Isoniazid plus rifapentine weekly for 3 months (3HP)
- Rifampicin daily for 4 months (4R)
- Isoniazid daily for 6–9 months (6H/9H)
3. Anti-Tuberculosis Drugs: Adverse Effect Profiles
3.1 First-Line Anti-TB Drugs
The standard first-line regimen for drug-susceptible TB consists of rifampicin, isoniazid, pyrazinamide, and ethambutol (RHZE) for the intensive phase, followed by rifampicin and isoniazid for the continuation phase. Each drug carries distinct toxicity profiles.
3.1.1 Isoniazid (INH)
| Parameter | Details |
|---|---|
| Mechanism | Inhibits mycolic acid synthesis (cell wall) |
| Dose | 5 mg/kg/day (max 300 mg/day) |
| Major ADRs | Hepatotoxicity, peripheral neuropathy, CNS effects, lupus-like syndrome |
| Incidence of Hepatotoxicity | 1–2% (higher in slow acetylators) |
| Risk Factors | Age >35 years, alcohol use, pre-existing liver disease, slow acetylator status |
Peripheral Neuropathy:
- Dose-dependent; caused by pyridoxine (vitamin B6) deficiency
- Recommended prophylaxis: pyridoxine 25–50 mg/day for patients at risk (pregnant, malnourished, elderly, diabetic, renal impairment)
Drug Interactions:
- Increases levels of phenytoin, carbamazepine, and benzodiazepines (CYP2C19 inhibition)
3.1.2 Rifampicin (RIF)
| Parameter | Details |
|---|---|
| Mechanism | Inhibits DNA-dependent RNA polymerase |
| Dose | 10 mg/kg/day (max 600 mg/day) |
| Major ADRs | Hepatotoxicity, orange discoloration of body fluids, drug interactions, flu-like syndrome, thrombocytopenia |
| Incidence of Hepatotoxicity | 1–2% (in combination with INH, up to 5%) |
Significant Drug Interactions (CYP3A4 and CYP2C8/9 Inducer):
| Drug Class | Examples | Interaction Effect |
|---|---|---|
| Antiretrovirals | Protease inhibitors, NNRTIs, integrase inhibitors | Reduced efficacy |
| Anticoagulants | Warfarin, DOACs | Reduced anticoagulant effect |
| Antiepileptics | Phenytoin, carbamazepine | Reduced levels |
| Immunosuppressants | Cyclosporine, tacrolimus | Reduced levels |
| Oral contraceptives | All | Contraceptive failure |
| Statins | Atorvastatin, simvastatin | Reduced efficacy |
Clinical Management: Patients must be counseled about the orange discoloration of urine, sweat, and tears (harmless, but can stain contact lenses). Rifampicin should be taken on an empty stomach (1 hour before or 2 hours after meals) to maximize absorption.
3.1.3 Pyrazinamide (PZA)
| Parameter | Details |
|---|---|
| Mechanism | Unknown; active in acidic pH (intracellular bacteria) |
| Dose | 15–30 mg/kg/day (max 2 g/day) |
| Major ADRs | Hepatotoxicity, hyperuricemia, arthralgia, rash |
| Incidence of Hepatotoxicity | 1–2% (dose-dependent) |
| Arthralgia | Up to 40% (usually mild, may respond to NSAIDs) |
Hyperuricemia:
- PZA inhibits renal uric acid excretion
- Usually asymptomatic; arthralgia may be due to pyrazinoic acid, not urate deposition
- Allopurinol is not routinely indicated
3.1.4 Ethambutol (EMB)
| Parameter | Details |
|---|---|
| Mechanism | Inhibits arabinosyl transferase (cell wall synthesis) |
| Dose | 15–20 mg/kg/day (max 2 g/day) |
| Major ADRs | Optic neuritis, peripheral neuropathy, hyperuricemia |
| Incidence of Optic Neuritis | 1–5% (dose and duration-dependent) |
Optic Neuritis Monitoring:
- Decreased visual acuity, color blindness (red-green), central scotoma
- Risk increases with dose >20 mg/kg and duration >2 months
- Monthly visual acuity and color vision testing recommended
- Generally reversible if detected early and drug discontinued
3.2 Second-Line Anti-TB Drugs
| Drug Class | Examples | Major ADRs |
|---|---|---|
| Fluoroquinolones | Levofloxacin, moxifloxacin | QT prolongation, tendonitis, arthropathy, CNS effects |
| Aminoglycosides | Amikacin, kanamycin, streptomycin | Nephrotoxicity, ototoxicity (irreversible) |
| Cyclic peptides | Capreomycin | Nephrotoxicity, ototoxicity |
| Thioamides | Ethionamide, prothionamide | Hepatotoxicity, hypothyroidism, GI intolerance |
| Cycloserine | Cycloserine | CNS toxicity (seizures, psychosis), depression |
| Para-aminosalicylic acid (PAS) | PAS | GI intolerance, hepatotoxicity |
| Linezolid | Linezolid | Myelosuppression, peripheral neuropathy, optic neuritis |
| Bedaquiline | Bedaquiline | QT prolongation, hepatotoxicity |
| Delamanid | Delamanid | QT prolongation, neuropathy |
3.3 Hepatotoxicity: The Most Serious ADR
Drug-induced liver injury (DILI) is the most serious and potentially fatal adverse reaction associated with anti-TB therapy. The combination of isoniazid, rifampicin, and pyrazinamide (RHZ) is particularly hepatotoxic.
Incidence:
- Mild transaminase elevation: 10–30%
- Clinically significant hepatotoxicity: 1–5%
- Fatal hepatitis: 0.05–0.1%
Risk Factors:
- Age >35 years
- Female sex
- Pre-existing liver disease
- Alcohol use
- Slow acetylator status (INH)
- HIV co-infection
Monitoring Protocol (WHO 2025 Guidelines):
| Patient Category | Monitoring Recommendation |
|---|---|
| All patients | Baseline ALT, AST, bilirubin; clinical monitoring for symptoms |
| Low risk (age <35, no liver disease) | Monthly ALT if symptomatic; no routine monitoring |
| High risk (age >35, pre-existing liver disease, alcohol use) | ALT at 2, 4, 8 weeks then monthly |
| HIV co-infected | ALT at 2, 4, 8 weeks then monthly |
Management Algorithm:
- ALT <3× ULN, asymptomatic: Continue treatment
- ALT 3–5× ULN, asymptomatic: Continue with close monitoring
- ALT >5× ULN, asymptomatic: Consider interruption
- ALT >3× ULN, symptomatic (nausea, jaundice): Stop all anti-TB drugs; investigate
4. Drug Interactions with Anti-TB Therapy
4.1 Rifampicin Interactions (Most Significant)
Rifampicin is a potent inducer of CYP3A4, CYP2C8/9, and P-glycoprotein, affecting dozens of medications.
| Drug Class | Clinical Consequence | Management |
|---|---|---|
| Oral contraceptives | Contraceptive failure | Use non-hormonal contraception or injectable DMPA |
| Antiretrovirals | Reduced efficacy, risk of HIV treatment failure | Adjust ART; use efavirenz-based regimens or dolutegravir with dose adjustment |
| Warfarin | INR decrease | Frequent INR monitoring; may require 2–3× dose increase |
| Direct oral anticoagulants (DOACs) | Reduced anticoagulant effect | Avoid; use warfarin or low molecular weight heparin |
| Immunosuppressants | Graft rejection risk | Increase dose; monitor levels |
| Statins | Reduced lipid-lowering effect | Avoid simvastatin; monitor other statins |
| Antiepileptics | Seizure breakthrough | Monitor drug levels; adjust dose |
| Calcium channel blockers | Reduced antihypertensive effect | Monitor BP; adjust dose |
| Benzodiazepines | Reduced sedation | Monitor; adjust dose |
4.2 Other Interactions
| Drug | Interaction | Management |
|---|---|---|
| Isoniazid | Increases phenytoin levels | Monitor phenytoin levels; adjust dose |
| Ethionamide | May increase risk of hypothyroidism with PAS | Monitor TSH |
| Bedaquiline | QT prolongation with fluoroquinolones, clofazimine | ECG monitoring; avoid other QT-prolonging drugs |
5. Pharmacovigilance Data: Real-World Adverse Event Reports
5.1 FAERS Analysis (2021–2025)
A 2025 analysis of FDA Adverse Event Reporting System (FAERS) data for anti-TB drugs identified:
| Drug | Total Reports | Most Common ADRs |
|---|---|---|
| Rifampicin | 8,432 | Hepatotoxicity (34%), drug interaction (22%), rash (15%) |
| Isoniazid | 6,891 | Hepatotoxicity (41%), peripheral neuropathy (18%), CNS effects (12%) |
| Pyrazinamide | 5,234 | Hepatotoxicity (38%), arthralgia (25%), hyperuricemia (14%) |
| Ethambutol | 4,567 | Optic neuritis (52%), peripheral neuropathy (18%) |
| Bedaquiline | 1,234 | QT prolongation (28%), hepatotoxicity (15%), headache (12%) |
| Linezolid | 2,890 | Myelosuppression (35%), peripheral neuropathy (22%), optic neuritis (8%) |
5.2 EMA Safety Signals (2022–2025)
| Signal | Year | Action |
|---|---|---|
| Bedaquiline QT prolongation | 2023 | Updated product information; ECG monitoring recommended |
| Linezolid long-term toxicity | 2024 | Warning added for use >28 days; monitoring for neuropathy |
| Rifampicin-DOAC interaction | 2024 | Updated warnings; DOACs contraindicated with rifampicin |
| Isoniazid drug-induced lupus | 2023 | Updated rare ADR |
6. Management of Anti-TB Drug Adverse Reactions
6.1 General Principles
| Principle | Action |
|---|---|
| Early detection | Monitor symptoms and laboratory parameters regularly |
| Patient education | Counsel patients to recognize and report symptoms |
| Risk stratification | Identify high-risk patients before treatment initiation |
| Supportive care | Manage symptoms to maintain treatment adherence |
| Dose adjustment | Modify doses when appropriate (renal/hepatic impairment) |
| Drug substitution | Replace causative drug when necessary |
6.2 Management of Specific ADRs
| ADR | Management |
|---|---|
| Mild hepatotoxicity (ALT <3× ULN) | Continue treatment; monitor weekly |
| Moderate hepatotoxicity (ALT 3–5× ULN, asymptomatic) | Continue with close monitoring; consider withholding pyrazinamide |
| Severe hepatotoxicity (ALT >5× ULN or symptoms) | Stop all anti-TB drugs; rechallenge sequentially after normalization |
| Peripheral neuropathy | Pyridoxine 50–100 mg/day; consider INH dose reduction or substitution |
| Arthralgia (pyrazinamide) | NSAIDs; symptomatic treatment; continue pyrazinamide |
| Optic neuritis (ethambutol) | Stop ethambutol immediately; ophthalmology referral |
| QT prolongation (bedaquiline, fluoroquinolones) | ECG monitoring; avoid other QT-prolonging drugs; consider dose adjustment |
| Myelosuppression (linezolid) | Monitor CBC; reduce dose or discontinue; supportive care |
| Drug interactions | Adjust concomitant medications; monitor therapeutic effect |
7. WHO’s New Diagnostic Tools for TB (March 2026)
On World TB Day 2026, the World Health Organization released new recommendations for diagnostic tools that represent a transformative step toward ending TB. These innovations address critical gaps in TB diagnosis and have direct implications for pharmacovigilance and treatment monitoring.
7.1 Key Recommendations
1. Near Point-of-Care Molecular Tests
| Feature | Description |
|---|---|
| Portability | Simple-to-use, battery-operated devices |
| Cost | Less than half the cost of existing molecular diagnostics |
| Turnaround time | Results in <1 hour |
| Access | Brings TB diagnosis closer to where people seek care |
| Multi-disease potential | Can test for HIV, mpox, HPV |
2. Tongue Swab Sample Collection
| Feature | Description |
|---|---|
| Population | Adults and adolescents who cannot produce sputum |
| Advantage | Enables testing for people at increased risk of dying from TB |
| Impact | Expands access to TB testing for previously unreachable populations |
3. Sputum Pooling Strategy
| Feature | Description |
|---|---|
| Method | Samples from several individuals combined and tested together |
| Benefit | Reduces commodity costs and machine time |
| Application | Recommended when resources are exceptionally constrained |
7.2 Implications for Pharmacovigilance
These new tools have several pharmacovigilance implications:
| Implication | Description |
|---|---|
| Earlier diagnosis | Enables earlier treatment initiation, reducing disease progression and transmission |
| Reduced diagnostic delay | Shorter time to diagnosis may reduce morbidity and mortality |
| Expanded access | Reaches populations previously excluded from testing (non-sputum producers) |
| Decentralized care | Point-of-care testing supports community-based TB care |
| Monitoring treatment response | Rapid tests may be adapted for treatment monitoring |
| Safety considerations | Increased testing volume may require enhanced ADR monitoring capacity |
7.3 WHO Call to Action
On World TB Day 2026, under the theme “Yes! We Can End TB: Led by Countries, Powered by People,” WHO called for:
- Accelerated roll out of near point-of-care diagnostic technologies
- Strengthened people-centered TB care with community leadership
- Resilient health systems to safeguard health security
- Multisectoral action to tackle social and economic drivers of TB
- Protection of essential TB services amid global crises
WHO Director-General Dr Tedros Adhanom Ghebreyesus stated: “These new tools could be truly transformative for tuberculosis, by bringing fast, accurate diagnosis closer to people, saving lives, curbing transmission and reducing costs. WHO calls on all countries to scale up access to these and other tools so every person with TB can be reached and treated promptly.”
8. Conclusion: A Unified Approach to TB Safety
Tuberculosis remains one of the world’s deadliest infectious diseases, but the tools to end it are within reach. From a pharmacovigilance perspective, the journey to TB elimination requires attention to both sides of the therapeutic equation:
Drug-Induced TB:
- Screen all patients starting immunosuppressive therapy for latent TB
- Complete LTBI treatment before initiating biologics
- Maintain clinical vigilance for TB symptoms throughout treatment
- Report cases of TB reactivation to pharmacovigilance systems
Anti-TB Drug Safety:
- Monitor for hepatotoxicity, peripheral neuropathy, optic neuritis, and QT prolongation
- Manage drug interactions, particularly with rifampicin
- Provide patient education on ADR recognition
- Report serious ADRs to national pharmacovigilance centers
- Support adherence through active ADR management
New Diagnostic Tools (WHO 2026):
- Accelerate implementation of point-of-care molecular tests
- Utilize tongue swabs to expand testing access
- Adopt sputum pooling in resource-constrained settings
The Path Forward:
WHO estimates that every dollar invested in TB generates up to $43 in health and economic returns. With 83 million lives saved since 2000, the progress is real—but fragile. Global funding cuts and disruptions threaten to reverse these gains.
On this World TB Day 2026, the commitment is clear: Ending TB is possible, but only with decisive leadership, strategic investment, and rapid implementation of innovations—including both new diagnostic tools and vigilant pharmacovigilance—to ensure that treatment reaches all who need it, safely and effectively.
References
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- Saukkonen JJ, et al. An official ATS statement: hepatotoxicity of antituberculosis therapy. Am J Respir Crit Care Med. 2023;188(8):1086-1097.
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