Spironolactone With Phentermine And Fluconazole Interaction

In our latest question and answer, the pharmacist discusses whether or not there is an interaction between spironolactone, phentermine and fluconazole.


I was prescribed phentermine 37.5mg by my general doctor. I was also prescribed spironolactone and fluconazole by my dermatologist. I just want to make sure there are no drug interaction before taking these.

Asked by Simmone On Jul 26, 2018

Answered by
Medical Content Reviewed By PharmacistAnswers Staff

On Jul 30, 2018

The only drug interaction between Phentermine, Spironolactone and Fluconazole is that Phentermine can cause an increase in blood pressure.  If Spironolactone was being taken for blood pressure control, this may be a concern.

Since the Spironolactone is being prescribed by your dermatologist, I am assuming you are taking it for different reasons.  If that is the case, there are no concerns and it is safe to take Phentermine, Spironolactone and Fluconazole together.  Some additional information on all three drugs can be found below.


Phentermine is a stimulant used in the treatment of obesity.  It should be used cautiously or avoided in patients with the following disease states:

  • Cardiovascular diseases including high blood pressure, stroke, heart rhythm abnormalities, heart failure and heart valve disease.
  • Diabetes
  • Renal impairment
  • Seizure disorders
  • Tourette syndrome

The most common side effect include:

  • Hypertension or high blood pressure
  • Heart palpitations
  • Fast heart beat
  • Dizziness
  • Headache
  • Insomnia
  • Restlessness
  • Change in libido or impotence
  • Constipation or diarrhea
  • Stomach upset
  • Tremor


Spironolactone is a diuretic or water pill used for the treatment of edema, heart failure, hypertension and primary hyperaldosteronism.  It has also been used in acne as an off-label use of the drug.  Off-Label use of a drug occurs when a drug is used for an unapproved indication that has not been approved by the FDA. 

Spironolactone is generally a well tolerated drug with the following as the most common side effects:

  • Gynecomastia (swelling of breast tissue in males)
  • Vomiting, diarrhea or stomach pain
  • Dizziness
  • Headache


Fluconazole is an anti-fungal drug used in the treatment of fungal infections including vaginal yeast infections. It should be used with caution in patients with liver or kidney impairment.  There are some potential serious drug reactions.  Patients should make sure their doctor and pharmacist are aware of any other medications they may be taking, including over the counter drugs or supplements. 

Some of the most common side effects include:

  • Headache
  • Dizziness
  • Nausea, vomiting, diarrhea or stomach upset


Taking Phentermine, Spironolactone and Fluconazole is considered safe for most patients.  For patients with high blood pressure, Phentermine can cause an increase in blood pressure and the benefits of the drug will need to be considered versus the risks associated with it.  

About the Pharmacist

Ms. Jennifer Hauder RPh

Jennifer Hauder is a registered pharmacist in the state of Illinois. She has over 10 years experience as a pharmacist in the retail and pharmacy benefit managers (PBM) settings. She became a pharmacist due to her interest in healthcare and the opportunity to help others with their healthcare needs. When not working, she enjoys spending time with her husband, three children and two black labs Lucky and Charms.

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