Overview

There are no known interactions between Prozac (fluoxetine) and the following medications:

They are all considered safe to take together.

If you are concerned about drug interactions between Prozac (fluoxetine) and other over the counter cough/cold medications, we wrote an extensive article on the subject which can be found here: Cold Medications To Avoid With Prozac.

Below is additional information on the drugs listed in your inquiry (Prozac, phenylephrine, guaifenesin).


About Prozac

Prozac (fluoxetine) is classified as a selective serotonin reuptake inhibitor (SSRI). It is most commonly used for the treatment of depression but is also indicated to treat certain anxiety and panic disorders.

SSRI medications, like Prozac, work via a complex mechanism of action but are thought to work primarily by increasing the amount of the neurotransmitter serotonin in the brain. In general, it can take up to 4-6 weeks to realize the full effects of the medication.

Prozac is associated with a variety of potential side effects, such as:

  • Weight fluctuations (gain and loss)
  • Headache
  • Dizziness
  • QT prolongation
  • Sexual dysfunction

Prozac is most commonly dosed once every 24 hours and can be taken with or without food.


About Phenylephrine

Sudafed PE (phenylephrine) is nasal decongestant available over the counter. Phenylephrine works to reduce congestion by constricting the blood vessels in the nose, reducing inflammation and opening the airways.

It is available as a single ingredient (phenylephrine) or in combination with other medications in various cough/cold products.

It is important to note that Sudafed PE and Sudafed contain different active ingredients. Sudafed (the non-PE version) contains pseudoephedrine and must be stored behind the pharmacy counter or in a locked case.

It may be taken with or without meals and reaches peak concentrations about 1-2 hours after taking by mouth. The duration of action of the drug is around 4 to 6 hours.


About Mucinex (Guaifenesin)

Guaifenesin is an oral expectorant (sometimes referred to as a 'mucolytic') and is commonly used to treat cough due to colds and minor upper respiratory infections.

Mucinex works by loosening and thinning phlegm and bronchial secretions to ease expectoration. By reducing the viscosity (i.e. thickness) and adhesiveness of secretions, guaifenesin increases the efficacy of the mucociliary mechanism in removing accumulated secretions from the upper and lower airway.

Mucinex is generally well tolerated and has few side effects or drug interactions.


Summary

  • There is no known interaction between Prozac, acetaminophen, guaifenesin and phenylephrine.

  • References
    1. Prozac Prescribing Information. Lilly
    2. DrugBank (PharmacistAnswers) Guaifenesin Monograph. DrugBank
    3. DrugBank (PharmacistAnswers) Phenylephrine Monograph. DrugBank