Br J Clin Pharmacol. 2021 Jul 15. doi: 10.1111/bcp.14985. Online ahead of print.
ABSTRACT
AIM: The Norwegian Association for Clinical Pharmacology in their National Guidelines decreased therapeutic range (TR) of topiramate (TPM) from 5-20 mg/L to 2-10 mg/L. The objective of this study is to ascertain which TR produces better clinical outcomes.
METHODS: Data source were request forms for routine therapeutic drug monitoring of TPM. Concentration dependent adverse drug reactions (ADRs) were evaluated in 1,721 samples taken pre-dose. Seizure frequency analysis was performed in 294 samples of monotherapy.
STATISTICS: Prism 5.0, GraphPad Instatt: One-way Anova with Bonferroni correction for median plasma level (PL). χ2-test with Bonferroni correction for seizure frequency and for distribution of PL according to TR 5-20 mg/L and intervals <2, 2-5, 5-10, 10-20, >20 mg/L.
RESULTS: Better seizure control was found in children both in whole cohort (without seizure 49% vs 37% adults), as well as in monotherapy (56% vs 44%), in children with PL 5-20 mg/L vs <5 mg/L (65% vs 44%) and in children with PL 5-10 mg/L vs <2 mg/L (63 vs 14%). PL in seizure-free patients did not differ from those with seizure. Seizure control was poorer in the period 2003-2005 compared to 2006-2011. ADRs reported in 38 samples (2.8%) were without relation to PL.
CONCLUSIONS: Change of TR is not recommended.
PMID:34265104 | DOI:10.1111/bcp.14985
