Safety and Efficacy of Mexidol® for ADHD in Children Aged 6-12

A Multicenter, Double-blind, Randomized, Placebo-controlled Clinical Trial in Three Parallel Groups to Evaluate the Effectiveness and Safety of Mexidol® Film-coated Tablets, 125 mg (LLC 'NPK PHARMASOFT', Russia) in the Treatment of Attention Deficit Hyperactivity Disorder (ADHD) in Children Aged 6-12 Years With Various Dosing Regimens (MEGA).

The primary objective of this study was to evaluate the efficacy and safety of Mexidol® film-coated tablets (125 mg) compared to a placebo in children aged 6 to 12 years with Attention Deficit Hyperactivity Disorder (ADHD). This multicenter, prospective, double-blind, randomized trial included 333 children who met the diagnostic criteria established by the International Classification of Diseases (ICD-10) and the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Participants received either Mexidol or placebo for 42 days, and various efficacy and safety parameters were assessed.

Inclusion Criteria:

1. Signed written informed consent for participation in the study from the patient's parents.

2. Patients - boys and girls aged 6 to 12 years, inclusive, at the time of signing the informed consent.

3. The child is raised by a father and/or mother.

4. The child is attending general education preschool or school institutions.

5. Diagnosis of Attention Deficit Hyperactivity Disorder (ADHD) established in accordance with ICD-10 and DSM-5 criteria by a psychiatrist or neurologist, specifically:

   - According to DSM-5:

   1. Six or more symptoms of inattention persisting for at least 6 months and/or

   2. Six or more symptoms of hyperactivity and impulsivity persisting for at least 6 months

   3. Symptoms are present in at least two areas of functioning (in preschool or school and at home).

      - And/or according to ICD-10:

   4. Presence of at least 6 symptoms of inattention

   5. Presence of at least 3 symptoms of hyperactivity

   6. Presence of at least 1 symptom of impulsivity

   7. Persisting for at least 6 months.

6. Moderate severity of ADHD as determined by the Clinical Global Impression - Severity Scale for ADHD (CGI-ADHD-S), not requiring hospitalization for treatment.

7. No more than two comorbid disorders that do not require additional pharmacotherapy, in the investigator's opinion, during the study period.

Exclusion Criteria:

Individuals who exhibit at least one of the following characteristics were not included in the study:

1. Increased sensitivity to the active substance of the investigational drug (ethylmethylhydroxypyridine succinate) and/or other components of the drug.
2. Liver dysfunction: ALT and/or AST ≥2.5 times the upper limit of normal (ULN) based on screening lab results.
3. Kidney dysfunction: serum creatinine ≥1.5 times ULN based on screening lab results.
4. Intracranial pathology (including but not limited to: intracranial hemorrhage, tumors, infections, history of head trauma, excluding concussion).
5. Co-occurring autism spectrum disorders, Asperger syndrome.
6. Intellectual disability of any degree.
7. Other mental disorders, except for behavioral disorders (ICD-10 code F91).
8. Inability to discontinue psychotropic medications used for the treatment of ADHD.
9. Other somatic and/or neurological disorders requiring treatment with medications that may affect the efficacy of the investigational drug (including but not limited to: epilepsy, depression).
10. Use of nootropic, vasoactive medications, neuroprotectors, antioxidants, or metabolic agents within 7 days or 5 half-lives (whichever is longer) prior to randomization.
11. Presence of any oncological disease in the medical history within 5 years prior to the screening visit.
12. Participation in any other clinical study of drugs and/or medical devices within 3 months prior to the screening visit and/or 5 half-lives, whichever is longer.
13. Inability or unwillingness to comply with protocol requirements, including for physical, mental, or social reasons, in the opinion of the investigator.
14. Lactose intolerance, lactase deficiency, glucose-galactose malabsorption.