Metabolic Acidosis is not Associated with Clinical Adverse Effects in Acetazolamide Use for Idiopathic Intracranial Hypertension in Children

Background: Idiopathic intracranial hypertension (IIH) is characterized by increased intracranial pressure with unidentified intracranial pathology. Acetazolamide, a carbonic anhydrase inhibitor is usually the first-line treatment for IIH. However, evidence-based data regarding its effectiveness and safety in children with IIH is still missing. The objective of the study was to profile the safety of acetazolamide use in the pediatric population and to inquire about the need for blood gas monitoring.

Methods: This retrospective study included children with IIH during 2007-2018 in 3 tertiary hospitals in Jerusalem. Inclusion criteria included children up to 18 years old; modified Dandy criteria of IIH; acetazolamide treatment and available blood gas tests during the treatment period. The computerized medical charts were reviewed to collect detailed demographic and clinical data.

Results: 68 patients (33 females and 35 males) were included with a mean acetazolamide treatment duration of 8.5 months. The mean maximal dosage was 20 mg/kg/d. 65 children had metabolic acidosis: 77.9% with mild acidosis, 14.7% with moderate acidosis and only 2.9% with severe acidosis. 18 children (26.5%) had at least one clinical adverse effect, including neurologic, gastrointestinal and renal side effects. We found no significant difference between the mean pH of children with and without clinical adverse effects (p=0.35), as well as no correlation between clinical adverse effects and laboratory acidosis (p=0.3).

Conclusions: Although metabolic acidosis is common among IIH patients treated with acetazolamide, it is not correlated with clinical adverse effects. Therefore, we do not recommend routine blood gas monitoring during acetazolamide treatment.