Moderate
Loratadine × Morphine
Second-generation antihistamines×Natural opium alkaloids
Mechanism
Loratadine is a second-generation antihistamine with minimal blood-brain barrier penetration. With opioids, mild additive CNS depression is possible, especially in older patients.
Symptoms
Sedation, fatigue, slowed reactions, impaired coordination. In older patients: fall and fracture risk. Driving and operating machinery: accident risk.
Management
No dose adjustment needed. In older patients and palliative care, watch for sedation signs. Loratadine is preferred over cetirizine or chlorpheniramine on concurrent opioid therapy — minimal sedation. With marked sedation, stop the antihistamine.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.