Possible removal of topiramate by continuous renal replacement therapy

Topiramate intoxications & hemodialysis - Literature review and the first case report of a massive suicidal intoxication treated with hemodialysis

Background

Topiramate is an anticonvulsant from sulfamate-substituted monosaccharides that is increasingly used to treat migraines. Serious topiramate intoxications have been described. Unfortunately, indications for and the effect of interventions, including hemodialysis, in severe intoxications seem expert-based and lack empirical evidence. We aim to review the literature on topiramate intoxication cases and to describe the first topiramate intoxication with toxicokinetic data following treatment with hemodialysis.

Methods

A literature review was conducted using the PubMed database. Included articles were reviewed for symptoms; management, including acute hemodialysis; toxicokinetic data; and outcomes.

Results

We found 61 hits in the PubMed database and checked 392 references in the snowball search; 22 were included for data extraction, reporting 29 cases. The majority of the patients were female (n = 23/29, 79%), ranging in age from 2 to 44 years (median 21). The ingested topiramate amount ranged from 175 to 40,000 mg (usual maintenance dose of 50 mg BID and a general maximum of 500 mg BID). Topiramate concentrations were reported in eight cases, ranging from 3.7 to 356.6 mg/L (for reference, the therapeutic range is 2-30 mg/L). Serious topiramate intoxications can result in seizures, coma, hemodynamic instability and severe metabolic acidosis. In no single case was hemodialysis used.

Conclusion

Serious symptoms of topiramate intoxications exist, and hemodialysis is used infrequently. If symptoms are refractory to symptomatic treatment, hemodialysis can reduce topiramate concentrations and symptomatology.

A Clinician's Guide to Dosing Analgesics, Anticonvulsants, and Psychotropic Medications in Continuous Renal Replacement Therapy

Acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT) is a common complication in critical illness and has a significant impact on pharmacokinetic factors determining drug exposure, including absorption, distribution, transport, metabolism, and clearance. In this review, we provide a practical guide to drug dosing considerations in critically ill patients undergoing CRRT, focusing on the most commonly used analgesic, anticonvulsant, and psychotropic medications in the clinical care of critically ill patients. A literature search was conducted to identify articles in which drug dosing was evaluated in adult patients receiving CRRT between the years 1980 and 2020. We included articles with pharmacokinetic/pharmacodynamic analyses and those that described medication clearance via CRRT. A summary of the data focused on practical pharmacokinetic and pharmacodynamic principles is presented, with recommendations for drug dosing of analgesics, anticonvulsants, and psychotropic medications. Pharmacokinetic and pharmacodynamic studies to guide drug dosing of analgesics, anticonvulsants, and psychotropic medications in critically ill patients receiving CRRT are sparse. Considering the widespread use of these medications, narrow therapeutic index of these drug classes, and risks of over- and underdosing, additional studies in patients receiving CRRT are needed to inform drug dosing.

Considerations for Medication Management and Anticoagulation During Continuous Renal Replacement Therapy

Providing safe and high-quality care to critically ill patients receiving continuous renal replacement therapy (CRRT) includes adequate drug dosing and evaluation of patients' response to medications during therapy. Pharmacokinetic drug studies in acute kidney injury and CRRT are limited, considering the number of medications used in critical care. Therefore, it is important to understand the basic principles of drug clearance during CRRT by evaluating drug properties, CRRT modalities, and how they affect medication clearance. Few published studies have addressed drug disposition and clinical response during CRRT. Additionally, clotting in the CRRT circuit is a concern, so a few options for anticoagulation strategies are presented. This article reviews (1) the CRRT system and drug property factors that affect medication management, (2) the evidence available to guide drug dosing, and (3) anticoagulation strategies for critically ill patients receiving CRRT.

Antiepileptic Drug Removal by Continuous Renal Replacement Therapy: A Review of the Literature

Continuous renal replacement therapy (CRRT) is used for managing acute kidney injury in critically ill patients. Removal of antiepileptic drugs (AEDs) by CRRT could be significant and may complicate patients' intensive care unit stay. The objective of the current review was to summarize the available evidence for AED removal by CRRT. An electronic literature search of PubMed (1946 to May 2016), Medline (1946 to May 2016), and Embase (1974 to May 2016) databases for studies discussing AED removal by CRRT was conducted. A total of 31 case reports discussing 32 patients were found. AEDs reported were levetiracetam (n = 3), valproic acid (n = 9), carbamazepine (n = 10), phenytoin (n = 3), phenobarbital (n = 4), lacosamide (n = 1), gabapentin (n = 1), and topiramate (n = 1). Two-thirds of the reports were about using CRRT in drug overdose and one-third was about AED removal by CRRT during therapy. Based on the current limited evidence and pharmacokinetic characteristics of AEDs, renally eliminated AEDs and/or AEDs with limited protein binding such as levetiracetam are more likely to be removed by CRRT than AEDs that are mainly metabolized and extensively protein bound such as carbamazepine. In conclusion, there is not enough evidence to provide robust dosing recommendations for AEDs in patients undergoing CRRT. Further studies are needed.

Antiepileptic dosing for critically ill adult patients receiving renal replacement therapy

OBJECTIVES

The aim of this review was to evaluate current literature for dosing recommendations for the use of antiepileptic medications in patients receiving renal replacement therapy (RRT).

DATA SOURCES

With the assistance of an experienced medical librarian specialized in pharmacy and toxicology, we searched MEDLINE, EMBASE, CINAHL, Web of Science, WorldCat, and Scopus through May 2016.

STUDY SELECTION AND DATA EXTRACTION

Four hundred three articles were screened for inclusion, of which 130 were identified as potentially relevant. Micromedex® DRUGDEX as well as package inserts were used to obtain known pharmacokinetic properties and dosage adjustment recommendations in RRT if known.

DATA SYNTHESIS

Data regarding antiepileptic drug use in RRT are limited and mostly consist of case reports limiting our proposed dosing recommendations. Known pharmacokinetic parameters should guide dosing, and recommendations are provided where possible.

CONCLUSION

Additional studies are necessary before specific dosing recommendations can be made for most antiepileptic drugs in critically ill patients receiving RRT, specifically with newer agents.