DRESS characteristics according to the causative medication.

BACKGROUND: To date, no study has identified a clear relationship between drug and a specific clinical presentation of DRESS. OBJECTIVES: To investigate the particularities of DRESS and analyze the variation of DRESS pattern according to culprit drugs. METHODS: We analyzed cases of DRESS notified to the Department of Clinical Pharmacology at the University Hospital of Monastir over a 15-year period. The statistical study was performed using the comparative and multivariate analysis. RESULTS: DRESS was mostly induced by anticonvulsive agents (27%) followed by allopurinol (26.3%) and antibiotics (24%): For anticonvulsive agents, the occurrence of lymphadenopathy was higher, renal involvement was rare and mild, and positive skin tests were more frequent. The allopurinol group was associated with the patient's older age and a lower incidence of lymphadenopathy and kidney injury. For antibiotics, eosinophilia rate was lower, time to recovery was shorter, and RegiSCAR score was low. The multivariate analysis showed a link of allopurinol with severe renal impairment, antibiotics with short latency period and low RegiSCAR score, and anticonvulsants with high propensity of positive skin test. CONCLUSION: We report the largest African and south Mediterranean cohort of DRESS and evaluated the usefulness of skin tests in identifying the culprit drug. The prominent finding was that latency period and renal involvement may independently differ according to culprit drugs.

Population pharmacokinetic model of isoniazid in patients with tuberculosis in Tunisia.

AIMS: To develop a pharmacokinetic model of isoniazid (INH) concentration taking into account demographic factors and genetic variables [N-acetyltransferase 2 (NAT2) genotype], and to propose an initial INH dosage that could maximize the probability of achieving the desired INH concentration. METHODS: A retrospective analysis was undertaken of INH concentration data collected from patients with tuberculosis in Tunisia. RESULTS: In total, 118 patients were included in this study. The one-compartment model [volume of distribution (V), elimination rate (Ke)] was found to have good predictive performance. Multi-variate analysis showed that NAT2 affected both V and Ke significantly, but age, gender and weight did not. Internal validation of the final model showed correlation of 0.95 between individual predicted INH concentration 3 h after drug intake (C3) and observed C3. External validation showed that percentage mean absolute prediction error and percentage root mean squared error were 9.11% (range 0.62-35.8%) and 11.6%, respectively. Monte-Carlo simulation showed that doses of at least 225 mg/24 h and at least 450 mg/24 h attained a therapeutic concentration in >80% of patients in the NAT2 slow acetylator group and the NAT2 rapid/intermediate acetylator group, respectively. CONCLUSION: The pharmacokinetic model allowed optimization of individual dosing regimens of INH in patients with tuberculosis in Tunisia. This tool may facilitate improved efficacy of INH and prevent its toxicity in this population.