Promethazine%2C Phenylephrine%2C Codeine + Ritonavir Interaction
Majorinteraction on record
Description
ketoconazole), or protease inhibitors (e.g., ritonavir), may result in an increase in codeine plasma concentrations with subsequently greater metabolism by cytochrome CYP2D6, resulting in greater morphine levels, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression, particularly when an inhibitor is added after a stable dose of Promethazine and Phenylephrine HCl and Codeine Phosphate Oral Solution is achieved [see Warnings and Precautions (5.9) ] .
Source: FDA drug label - promethazine, phenylephrine, codeine