Pilot Study of Riluzole for Drug-Refractory Irritability in Autism Spectrum Disorders

Inclusion Criteria:

- Age ≥ 12 and < 26 years.

- Weight greater than 50 kg.

- Diagnosis of ASD

- Drug-refractory irritability, as defined as screening ABC Irritability subscale
(ABC-I) score of ≥18 AND 1) failure of clinically adequate treatment trials of both
aripiprazole and risperidone or 2) failure of at least three previous clinically
adequate drug trials targeting irritability (one trial must include aripiprazole or
risperidone), as confirmed by caregiver reports and medical record review when
available.

- Stable dosing of all concomitant psychotropic medications (including those targeting
irritability) for four weeks prior to screening visit and during the study.

- Presence of parent/guardian willing to serve as informant for behavioral outcome
measures and shipping control sample for Extracellular Signal-Related Kinase
biomarker (ERK) assay.

Exclusion Criteria:

- Current use of more than two concomitant psychotropic drugs targeting irritability.

- Current use of valproic acid.

- Current use of drugs with known interaction with riluzole

- Current use of drugs with concomitant glutamatergic or glutamatergic- modulating
action medications.

- For female subjects of child bearing potential, a positive serum pregnancy test.

- History of pancreatitis.

- Hemoglobin less than or equal to 8.0 gm/dL.

- Neutropenia with absolute neutrophil count less than or equal to 1.0 K/mcL.

- Problems with kidney functioning, as assessed by lab work

- Any major chronic medical or chronic respiratory illness considered to be
uncontrolled by the Principal Investigator.