RESUMO
Introduction: Valproic acid is a commonly used antiepileptic drug. Combining valproate derivatives with carbapenem antibiotics is associated with a potential drug interaction that decreases serum concentration of valproate and may expose the patient to uncontrolled seizure risk from valproate subtherapeutic concentration. Raising awareness of this drug interaction among health care providers including emergency department physicians, neurologists, and pharmacists is highly needed. The aim of this article was to review the current literature about the potential drug interaction resulting from combining valproate derivatives with carbapenem antibiotics and to establish therapeutic recommendations regarding their use together. Methods: A review of the literature was conducted using Medline (through PubMed), Ovid, Embase, Cochrane library using the following keywords: valproate, valproic acid, carbapenem, ertapenem, doripenem, meropenem, imipenem, and valproate drug interaction. In addition, a manual search through major journals for articles referenced in PubMed was performed. Related publications from January 1998 till November 2018 were included in the initial search. Relevant publications were reviewed, and data regarding patients, type of carbapenem used, valproic acid dosing and level, interaction severity, and clinical outcome were summarized. Results and Discussion: Few clinical trials and multiple case reports have shown that carbapenem antibiotics including meropenem, ertapenem, imipenem, and doripenem can decrease the serum concentration of valproate derivatives leading to a subtherapeutic serum concentration and seizures in some patients. Valproic acid serum concentration may be significantly decreased with addition of a carbapenem antibiotic but generally return toward normal shortly after discontinuation of the carbapenem antibiotic. Conclusions: Generally, the concurrent use of carbapenem antibiotics with valproate derivatives should be avoided due to the potential of drug-drug interaction that results in subtherapeutic valproate serum concentration. Other antimicrobial agents should be considered as alternatives to carbapenems but if a concurrent carbapenem is necessary, using an additional antiepileptic agent is recommended. Therapeutic drug monitoring of valproate serum concentrations is warranted when a carbapenem-valproic acid combination therapy is unavoidable.
RESUMO
We report a case of acute disseminated encephalomyelitis (ADEM) secondary to Mycoplasma pneumoniae infection that failed to improve with methylprednisolone and intravenous immunoglobulin (IVIG); who responded with plasmapheresis. A 21- year- old female with an unremarkable medical history, initially presented to an outside hospital with fever and an influenza-like illness and was subsequently intubated for worsening sensorium. Brain magnetic resonance imaging was suggestive of ADEM or vasculitis for which she received five days of pulse steroids and IVIG. She showed no signs of improvement and was transferred to our hospital for plasmapheresis. Her work up revealed an elevated IgM antibody and positive sputum for Mycoplasma pneumonia by polymerase chain reaction, suggesting the pathogen as the culprit for her ADEM. Intravenous azithromycin and daily plasmapheresis were initiated for seven consecutive days. Following commencement of her treatment, the patient experienced good recovery and was subsequently extubated. She continued to improve with physical therapy and gained mobility, with the help of a walker. Patients commonly present with ADEM following viral infection or vaccination and less frequently post bacterial infection. The current treatment of ADEM due to Mycoplasma pneumoniae is based on limited case reports. Our patient poorly responded to pulse steroids and IVIG, while she markedly improved on azithromycin and plasmapheresis. In patients presenting with encephalopathic signs and neurological manifestations following pneumonia; Mycoplasma pneumoniae infection and subsequent immune-mediated demyelination should be considered.
