dfbag asked
Can you take Prozac with Coreg (carvedilol)? I've gotten differing opinions from doctors and pharmacists.
At a glance
- Drug concentrations of Coreg (carvedilol) can be increased if taken along with Prozac.
- This interaction occurs because Prozac inhibits the metabolizing enzyme CYP2D6, which is partially responsible for metabolizing Coreg in our body.
- Increased concentrations of Coreg can increase the risk of dose-related side effects, such as dizziness, low blood pressure and decreased heart rate.
- Even though this interaction exists, they are still often prescribed together but you should be monitored closely by your doctor.
Answer
There is a potential drug interaction between Prozac (fluoxetine) and Coreg (carvedilol).
While this drug combination can be taken together safely by many people, it is important to understand what the interaction actually is and what to look out for if you do take the drugs together.
You mentioned that you've gotten various opinions from medical professionals on this subject and this isn't uncommon. Even reputable drug information resources often offer conflicting data on interactions, which adds to the confusion.
For example, Clinical Pharmacology, one of the premier professional drug information resources, lists the interaction between Prozac and Coreg as 'minor' while others, like Drugs.com, lists it as a 'moderate' interaction. Our own interaction checker, which pulls data from Drugbank.ca, classifies it as a 'major' interaction. So, which is right?
To summarize the interaction, taking Prozac with Coreg can result in increased drug concentrations of Coreg in the body, which increases the likelihood of side effects occurring (like low blood pressure and dizziness).
However, this won't affect everyone in a significant manner and the interaction can fairly easily be managed by adjusting your dose of Coreg if necessary. I discuss the interaction in more detail below.
Interaction Detail
Drugs can interact with each in many ways, but the primary mechanism behind most involves an alteration of their metabolism (i.e. the rate at which they are processed in our body). That is the mechanism behind the interaction between Prozac and Coreg.
Prozac is a well-known inhibitor of the metabolizing enzyme CYP2D6. The prescribing information for the drug discusses this in detail:
Fluoxetine [Prozac] inhibits the activity of CYP2D6, and may make individuals with normal CYP2D6 metabolic activity resemble a poor metabolizer.
Coreg is metabolized by a few different enzymes, CYP2D6 included.
The prescribing information for the drugs warns of the increased potential of side effects if it is taken along with other drugs that inhibit CYP2D6. In one section of the prescribing information for Coreg, the following is stated:
