Encephalopathy secondary to isoniazid in patients on hemodialysis

Extracorporeal treatments for isoniazid poisoning: Systematic review and recommendations from the EXTRIP workgroup

Isoniazid toxicity from self-poisoning or dosing errors remains common in regions of the world where tuberculosis is prevalent. Although the treatment of isoniazid poisoning is centered on supportive care and pyridoxine administration, extracorporeal treatments (ECTRs), such as hemodialysis, have been advocated to enhance elimination of isoniazid. No systematic reviews or evidence-based recommendations currently exist on the benefit of ECTRs for isoniazid poisoning. The Extracorporeal Treatments in Poisoning (EXTRIP) workgroup systematically collected and rated the available evidence on the effect of and indications for ECTRs in cases of isoniazid poisoning. We conducted a systematic review of the literature, screened studies, extracted data on study characteristics, outcomes, and measurement characteristics, summarized findings, and formulated recommendations following published EXTRIP methods. Forty-three studies (two animal studies, 34 patient reports or patient series, and seven pharmacokinetic studies) met inclusion criteria. Toxicokinetic or pharmacokinetic analysis was available for 60 patients, most treated with hemodialysis (n = 38). The workgroup assessed isoniazid as "Moderately Dialyzable" by hemodialysis for patients with normal kidney function (quality of evidence = C) and "Dialyzable" by hemodialysis for patients with impaired kidney function (quality of evidence = A). Clinical data for ECTR in isoniazid poisoning were available for 40 patients. Mortality of the cohort was 12.5%. Historical controls who received modern standard care including appropriately dosed pyridoxine generally had excellent outcomes. No benefit could be extrapolated from ECTR, although there was evidence of added costs and harms related to the double lumen catheter insertion, the extracorporeal procedure itself, and the extracorporeal removal of pyridoxine. The EXTRIP workgroup suggests against performing ECTR in addition to standard care (weak recommendation, very low quality of evidence) in patients with isoniazid poisoning. If standard dose pyridoxine cannot be administered, we suggest performing ECTR only in patients with seizures refractory to GABA_A receptor agonists (weak recommendation, very low quality of evidence).

Tolerability and Healthcare Utilization in Maintenance Hemodialysis Patients Undergoing Treatment for Tuberculosis-Related Conditions

BACKGROUND

The incidence of tuberculosis (TB) in end-stage renal disease is significantly higher than that in the general population. Among those with kidney dysfunction, anti-TB treatment is associated with increased side effects, but the effect on healthcare utilization is unknown. Methods/Aim: To assess patient-reported symptoms, adverse effects and describe changes in healthcare utilization patterns during treatment for TB, we conducted a case series (n = 12) of patients receiving maintenance hemodialysis (HD) from Mayo Clinic Dialysis Services and concurrent drug therapy for TB from January 2002 through May 2014. Healthcare utilization (hospitalizations and emergency department (ED) visits independent of hospital admission) was compared before and during treatment.

RESULTS

Patients were treated for latent (n = 7) or active (n = 5) TB. The majority of patients with latent disease were treated with isoniazid (n = 5, 71%), while active-disease patients received a 4-drug regimen. Adverse effects were reported in 83% of patients. Compared to measurements prior to drug initiation, serum albumin and dialysis weights were similar at 3 months. Commonly reported anti-TB drug toxicities were described. More than half (58%) of the patients were hospitalized at least once. No ED or hospital admissions occurred in the period prior to drug therapy, but healthcare utilization increased during treatment in the latent disease group (hospitalization rate per person-month: pre 0 vs. post 1).

CONCLUSIONS

Among HD patients, anti-TB therapy is associated with frequently reported symptoms and increased healthcare utilization. Among this subset, patients receiving treatment for latent disease may be those with greatest increase in healthcare use. Careful monitoring and early complication detection may help optimize medication adherence and minimize hospitalizations.