Fluconazole: What is it? Operation, Side Effects, Interactions and Important Aspects

It is a medicine prescribed by a specialist to fight fungal infections called Candidiasis or another type of fungus.

This disease can be present in the vagina, mouth, throat, esophagus, lungs, and blood.

People who have undergone bone marrow transplants are more likely to become infected with a severe form of Candidiasis because their immune system is lower at that time.

Fluconazole also treats meningitis (brain and spinal cord) caused by the fungus Cryptococcus.

Functioning of Fluconazole

This antibiotic blocks the reproductive capacity of fungi Candida and Cryptococcus.

For people at increased risk of Candidiasis, it helps to prevent an infection from occurring.

Side effects

Some patients have recorded several side effects, but it all depends on the amount of medicine that the treating doctor has indicated and the functioning of the body’s immune system. The most frequent are:


  • Headache.
  • Diarrhea.
  • Nausea or upset stomach
  • Dizziness.
  • Vomiting
  • Severe rash in people with low immunity.

Serious side effects and why you should stop treatment with Fluconazole are:

  • Yellowing of your skin or the whites of your eyes.
  • Dark urine.
  • Stool light-colored.
  • Severe rash in people with acquired immunodeficiency syndrome (AIDS) or cancer.
  • Cardiac arrhythmia.
  • Convulsions


Because it is an invasive antibiotic, you must be very careful with its treatment since it can bring severe consequences to your health if it is ingested with the following medications:

Quinidine: when used with Fluconazole in 400 mg or more doses, this medication can cause a life-threatening heart rhythm condition.

Voriconazole: this medicine, together with Fluconazole, can cause vision problems, fever, nausea, rash, vomiting, liver function problems, rapid pulse, and hallucinations.

Glyburide and Glipizide: may include a low level of blood sugar, which causes symptoms such as sweating and chills, tremors, rapid pulse, weakness, and dizziness.

Warfarin: may cause bruising, nosebleeds, and blood in the urine or stool.

Phenytoin: causes coordination problems, difficulty speaking, and confusion.

Ciclosporin, Tacrolimus, and Sirolimus: include kidney damage.

Theophylline produces muscle cramps, headaches, low blood pressure, and seizures.

Zidovudine: prone to causing headache, tiredness, loss of appetite, nausea, and vomiting.

Carbamazepine: may cause nausea, vomiting, unsteadiness, low blood cell counts, severe rash, heart failure, and liver failure.

Chlorpromazine, Haloperidol, and Ziprasidone: increase the risk of an irregular heart rhythm condition that endangers life.

Important aspects

This medicine may cause you to develop liver failure, change your heart rate, and allergic reactions such as:

  • Difficulty breathing.
  • Chronic cough.
  • Fever
  • Swelling of the eyelids, face, mouth, neck, or other body parts.
  • Skin rash, hives, blisters, or peeling skin

If you currently have kidney disease and should take this medicine, your kidneys may not be able to remove the Fluconazole components from your body as they should. This can worsen existing kidney disease.

The oral suspension of this medication contains sucrose, a type of sugar. You should not use this form of medicine if you have a condition that increases your blood sugar level.

If you are pregnant, Fluconazole may have adverse effects on the fetus. This medicine should only be used during pregnancy in severe cases where a dangerous condition needs to be treated in the mother.

If you are breastfeeding, avoid taking Fluconazole, as it may affect the baby.

This medicine should not be used in people younger than six months.

The oral tablet of Fluconazole is used for short and long-term treatment. If you stop taking the medication suddenly or do not take it, your infection may not improve or worsen.

If you take too much, you could have dangerous drug levels in your body. Symptoms of an overdose of this medication may include:

  • Hallucinations
  • Paranoia.
  • Abnormal heart rhythm
  • Skin with blue color.
  • Decreased breathing

If you experience any of the above symptoms and feel that you have taken too much of this medication, stop using it and contact your treating doctor to prevent further sequelae.