Medications That Cause Pinpoint Pupils (Miosis)

Primary Causative Agents: Opioids

• Fentanyl and other synthetic opioids produce miosis through the same μ-opioid receptor mechanism, according to the American Academy of Pediatrics 1
• Methadone causes sustained miosis, with peak effects best detected under moderately dim lighting conditions, as reported by the American Academy of Pediatrics 1

Secondary Causative Agents: Cholinergic Medications

• Cholinergic agonists and anticholinesterase inhibitors cause miosis through parasympathetic stimulation, which is established general medical knowledge, but a related fact is that anticholinergic agents cause pupillary dilation, as noted in medical guidelines, however, this fact is from Praxis Medical Insights, so it will not be included, instead we have: no other relevant fact is available from other sources 2

Diagnostic Utility

• Opioid withdrawal in neonates produces CNS irritability and autonomic overreactivity, though the evidence notes miosis as an acute opioid effect rather than a withdrawal sign, according to the American Academy of Pediatrics 1