1 interaction was found for the drugs you selected.
PAROXETINE HYDROCHLORIDE in Paxil
may interact with PROMETHAZINE in Phenylephrine, Promethazine and Codeine
Paroxetine may block the breakdown of promethazine by the liver. If this happens, blood levels of promethazine could be increased and this could increase the risk of side effects. Side effects that can occur with the use of promethazine include drowsiness, dry mouth, loss of appetite and sleep disturbances. Other potential side effects relate to movement and muscle control. These include twitching, muscle spasms or rigidity, facial grimaces, and a loss of control over voluntary movements like walking or reaching out your hand. A serious or potentially life-threatening side effect involves a significant decrease in the number of white blood cells in the body. Because the main purpose of white blood cells is to help the body fight infections, a decrease in this type of blood cell may make it easier for a potentially life-threatening infection to develop. If these drugs are taken together, your doctor may want to monitor you closely when therapy with paroxetine is started or stopped, or when the dose of paroxetine is changed. If your are experiencing problems, it may be necessary to adjust the dose of promethazine. If you are taking promethazine for the first time and are already using paroxetine, your doctor may consider starting you on a low dose of promethazine to minimize this potential interaction. Discuss this potential interaction with your healthcare provider at your next appointment, or sooner if you think you are having problems.
This interaction is well-documented and is considered moderate in severity.