Moderate
Established
Descripción
Concurrent use of cetirizine and oxycodone may produce additive CNS and respiratory depression, increasing the risk of sedation and, at higher doses, respiratory compromise.
Mecanismo
Oxycodone activates mu-opioid receptors causing CNS and respiratory depression; cetirizine's residual CNS H1 antagonism adds to sedation; combined pharmacodynamic suppression of the central nervous system is greater than either agent alone.
Relevancia clínica
The FDA opioid labelling warns of additive depression with all CNS depressants including antihistamines; case reports of respiratory depression exist.
Manejo clínico
If the combination is necessary, use the lowest effective doses; counsel patients to avoid alcohol and other CNS depressants; monitor for excessive sedation.