Risk factors for sodium valproate-induced renal tubular dysfunction

Valproic acid as an adjuvant analgesic: adult Fanconi syndrome

We report an 80-year-old woman who developed severe hypophosphataemia and elevated urinary phosphate levels while started on valproic acid. This occurred within 1-2 days of starting valproic acid. There are rare single-patient reports of the association of valproic acid with adult Fanconi syndrome. This generally occurs after long-term exposure to valproate. This is the first reported experience of Fanconi's syndrome in an adult with acute exposure to valproic acid. Clinicians should be aware of the possible association.

Kidney tubular injury induced by valproic acid: systematic literature review

BACKGROUND

Valproic acid is prescribed for epilepsy and as prophylaxis for bipolar disorder and migraine headaches. It has also been implicated as a cause of a kidney tubular injury.

METHODS

We undertook a review of the literature to characterize the biochemical and histopathological features of the overt kidney tubular injury and to evaluate the possible existence of a pauci-symptomatic injury. The pre-registered review (CRD42022360357) was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. Searches were conducted in Excerpta Medica, the National Library of Medicine, and Web of Science. The gray literature was also considered.

RESULTS

For the final analysis, we retained 36 articles: 28 case reports documented 48 individuals with epilepsy on valproic acid for 7 months or more and presenting with features consistent with an overt kidney tubular injury. The following disturbances were noted: hypophosphatemia (N = 46), normoglycemic glycosuria (N = 46), total proteinuria (N = 45), metabolic acidosis (N = 36), hypouricemia (N = 27), tubular proteinuria (N = 27), hypokalemia (N = 23), and hypocalcemia (N = 8). A biopsy, obtained in six cases, disclosed altered proximal tubular cells with giant and dysmorphic mitochondria. Eight case series addressed the existence of a pauci- or even asymptomatic kidney injury. In the reported 285 subjects on valproic acid for 7 months or more, an isolated tubular proteinuria, mostly N-acetyl-β-glucosaminidase, was often noted.

CONCLUSIONS

Valproic acid may induce an overt kidney tubular injury, which is associated with a proximal tubular mitochondrial toxicity. Treatment for 7 months or more is often associated with a pauci- or oligosymptomatic kidney tubular injury. A higher resolution version of the Graphical abstract is available as Supplementary information.

Sex differences in side effects of antiseizure medications in pediatric patients with epilepsy: A systematic review

PURPOSE

To perform a systematic review searching for differences in the side effects of antiseizure medications (ASMs) with respect to sex in pediatric patients with epilepsy.

METHODS

We carried out a comprehensive literature search of the PubMed database and all results up to April 2020 were included. Titles, abstracts, and full texts of the articles were screened by two independent reviewers. We included all studies evaluating the side effects of ASMs in patients with epilepsy younger than 18 years, with reference to the two sexes. Studies on ASMs used for indications other than epilepsy were excluded.

RESULTS

A total of 5164 studies were identified. Sixty-seven studies were finally included, 5 of them also including adult patients in the sample. Sixteen studies revealed sex-related differences in side effects of ASMs, disclosing a higher frequency of general side effects in girls: a higher risk of overweight, hyperammonaemia, high leptin levels, and carnitine deficiency in girls on valproic acid; a lower height increase, an increased risk of weight loss, the anecdotical occurrence of acute psychosis in girls on topiramate; a higher risk of retinal toxicity in boys on vigabatrin.

CONCLUSION

The effect of sex on susceptibility to side effects of ASMs is poorly investigated with sparse results, and it could be underestimated. The findings of our study point to the presence of sex differences which should be thoroughly investigated to be confirmed, highlighting the need for a systematic evaluation of sex as a determinant variable influencing the response to medications in clinical research.

Valproate attenuates hypertonic glycerol-induced rhabdomyolysis and acute kidney injury

BACKGROUND AND AIM

The current study investigated the effects of treatment with 300 mg/kg valproic acid on rhabdomyolysis and acute kidney injury induced by intramuscular injection of hypertonic glycerol in rats.

METHODS

Four groups of male wistar rats: control and hypertonic glycerol, valproic acid and valproic acid + hypertonic glycerol treated groups were used. Blood urea nitrogen, serum creatinine, creatinine kinase (CK) and CK MB, myoglobin and renal reduced glutathione (GSH) levels were measured. Histopathological examination of the kidneys was carried out to evaluate the degree of renal injury in each group. The expression of interleukin-1 beta "IL-1β" in renal tissue was detected using immunohistochemistry.

RESULTS

Hypertonic glycerol administration led to severe renal tubular damage with a significant elevation of blood urea nitrogen, serum creatinine, creatinine kinase, CK MB and myoglobin levels and overexpression of IL-1β compared to control group. Valproic acid administration attenuated both the muscle injury and the acute kidney injury induced by hypertonic glycerol, estimated through a significant reduction of creatinine kinase, myoglobin, and serum creatinine. Valproic acid administration caused a significant increase in GSH in the hypertonic glycerol + valproic acid group compared to the hypertonic glycerol group. A significant decrease in tubular necrosis grade, and expression of IL-1β in hypertonic glycerol + valproic acid group compared to the hypertonic glycerol group was observed.

CONCLUSION

This study demonstrates, for the first time to the best of our knowledge, that valproic acid could ameliorate the rhabdomyolysis and the related acute kidney injury in rats.