Introduction: Substance use disorder (SUD), traditionally viewed as an adolescent or adult pathology is emerging in the pediatric population, representing a growing clinical and public health crisis worldwide. Case presentation: A 11 year old schoolboy presenting with hyperventilation and carpopedal spasms following moderate exertion. He was a known child with bronchial asthma who was off inhalers for one and a half years. There was no history of obstructive sleep apnoea.The carpopedal spasms and shortness of breath settled soon after admission and the lungs were clear and there was no respiratory distress. His investigations: Rbs 103, Corrected Ca 2.4 (N), Total Ca 2.5 Phosphorus 1.4 (N), CPK 180 (0-145), VBG Normal, Ast 23, ALT 12, K 3.8, Na 143, Cl 107 , Urea 28.7 , S Creat 52.2 (N). He was started on face mask oxygen as he had oxygen saturation dips as low as 63% as soon as he sleeps, which rose to 100% while awake. A urine toxicology screen was done as his physical findings did not correlate with the drop in saturation and was found to be positive for Barbiturates & MDMA. He confessed to substance abuse the next day and made a full recovery . Conclusion: Early detection of undisclosed substance abuse through clinical vigilance can prevent potentially fatal respiratory failure and allow for the timely mobilization of multidisciplinary resources, such as Toxicology and Pharmacovigilance to identify the agent, social services to ensure the safety of the child’s environment and developmental psychiatry to address the root cause of the ingestion.