Itraconazole 100 mg: What is it? How does it work? Secondary Effects, Administration and Precautions

It is used to treat a variety of fungal infections. It belongs to a class of medications known as azole antifungals. It works by stopping the growth of fungi.

What conditions does Itraconazole treat?

Itraconazole oral capsules of 100 mg are used for the treatment of systemic fungal infections, including blastomycosis (pulmonary and extrapulmonary), histoplasmosisand aspergillosis (pulmonary and extrapulmonary).

The oral solution of Itraconazole (but not the capsules) is used for the treatment of oropharyngeal and esophageal candidiasis.

And oral Itraconazole capsules are used in immunocompetent individuals for the treatment of onychomycosis. It is also used for the prevention of severe fungal infections in patients with human immunodeficiency virus ( HIV ) infection .

Other uses:

  • Histoplasmosis.
  • Fungal infection of the nail of the foot.
  • Aspergilosis.
  • Blastomicosis.
  • Peniciliosis.
  • Infection in patients with neutropenic fever.
  • Fungal infection of the skin.
  • Fungal infection of the esophagus.

How does it work?

The 100 mg Itroconazole capsules work by preventing fungi from producing a substance called Ergosterol, which is an essential component of fungal cell membranes.

These are vital for your survival. They prevent unwanted substances from entering the cells and the contents to leak.

Without Ergosterol, the fungal membrane becomes weak and damaged. This kills them and therefore eliminates the infection.

How is the medication administered?

Before you start taking Itraconazole, and each time the prescription is renewed, you should read the patient information leaflet that comes in the medication or consult the pharmacist.

If you have any questions you need to consult a doctor or pharmacist.

Take this medication as directed by a doctor. However, the most frequent orders they can give are taking the medication orally with a complete meal, usually once or twice a day. The capsules should be swallowed whole and without chewing.

Some conditions may require you to take it in cycles (twice a day for 1 week and then suspend the medication for 3 weeks).

Take Itraconazole 2 hours before or 1 hour after antacids because these can decrease the absorption of the medication.

Also, swallow the capsules with an acidic beverage (such as cola) if you have decreased or absent stomach acid (achlorhydria) or if you take medications that decrease it (such as Ranitidine or Omeprazole).

Dosage and duration are based on your medical condition and response to treatment. To get the best effect, take it at regular intervals.

Note: To help you remember the administration form, try to take Itraconazole at the same time every day. Mark your calendar with a reminder if you are taking it in cycles.

Continue taking it until the prescribed amount is completed, even if the symptoms disappear after a few days. Stopping the medication too soon may cause the infection to reappear.

Tell your doctor if your problem does not improve or if it gets worse.

Administration in specific conditions:

All doses are suitable for adults and children over 12 years.

  • Oropharyngeal candidiasis: 100 mg daily for 15 days. (1 capsule)
  • Vulvovaginal candidiasis:  400 mg in two divided doses taken on the same day. (4 capsules).
  • Skin infections:  200 mg daily for 15-30 days. (2 capsules).
  • Subcutaneous and systemic fungal infections:  200-400 mg daily during the time that the lesions persist. (2 to 4 capsules)

Higher doses may be needed in patients with nail infections: 400 mg daily for 7 consecutive days for 3 months. (4 capsules)

Side effects

  • Sickness.
  • Vomiting
  • Diarrhea.
  • Headache.
  • Upset stomach or dizziness

Tell your doctor immediately if you have any of these serious side effects:

  • Numbness.
  • Tingling of arms or legs.
  • Mental changes
  • Depression.


  1. If any of these effects last or worsen, inform your doctor or pharmacist promptly.
  2. Many people using this medication do not have serious side effects.
  3. Itraconazole can usually cause a mild rash that is usually not serious. However, you may not be able to distinguish it.
  4. A very serious allergic reaction to this medication is rare. However, seek medical attention immediately if you develop: Rash, itching. Swelling (especially on the face, tongue, throat) Severe dizziness or difficulty breathing

Itraconazole can also have side effects in the ears. It can cause hearing loss that usually resolves when treatment is stopped, but it can also be permanent in some cases. Tell your doctor immediately if you think your hearing is affected.

If you experience abnormal sensations in your feet and hands, for example: numbness, tingling, or the sensation of burning or pain, it could be indicative of a nerve problem called peripheral neuropathy. Your doctor may want you to stop taking this medication.

This is not a complete list of possible side effects. If you notice other effects not mentioned above, contact your doctor or pharmacist.

Precautions and Warnings about Itraconazole

This product may contain inactive ingredients that can cause allergic reactions or other problems. Consult your pharmacist for more details.

Before taking Itraconazole, tell your doctor or pharmacist if you are allergic to it; or to other azole antifungals (such as Ketoconazole); or if you have any other allergies.

Also inform your doctor about your medical history, especially if they record: liver diseases, kidney diseases, heart disease, lung diseases, the decrease or absence of stomach acid.

This medicine may cause dizziness. Alcohol or marijuana can make you more dizzy.

Do not drive or do anything that requires alertness until you can do it safely.

Avoid alcoholic beverages. Talk to your doctor if you are using marijuana. Alcohol can also increase the risk of serious liver problems.

Before having surgery, tell your surgeon or dentist about all the products you are using (including prescription drugs, over-the-counter medications, and herbal products). This is very important for your physical well-being.

Older adults may have an increased risk of hearing loss while using this medication.

Itraconazole, although very rarely, can cause liver problems. For this reason, your doctor may ask you to have regular blood tests to check your liver function while taking this medication.

Itroconazole during pregnancy or lactation

This medication should be used only when clearly necessary (when the infection being treated threatens the life of the pregnant woman and the possible benefit of the treatment does not express any potential risk to the developing baby).

This is because the medication could harm an unborn baby. Discuss the risks and benefits with your doctor.

This medication should not be used to treat fungal nail infections if you are pregnant or if you have heart disease.

Women who might become pregnant should use an effective contraceptive method to avoid pregnancy while taking this medication.

Preferably a barrier method, such as condoms, should be used, as this medication may reduce the effectiveness of birth control pills.

After you have finished the Itraconazole course, you should continue using contraceptives until your next menstrual period.

Itraconazole passes into breast milk. Women who need treatment with this medication should not breast-feed.


Interactions with other medications can change the functioning of Itraconazole or increase the risk of serious side effects.

Keep a list of all the products you are using (including over-the-counter and non-prescription medicines and herbal products) and share it with your doctor and pharmacist.

Do not start, stop or change the dosage of any medication without your doctor’s approval.

Medications that can affect the functioning of Itraconazole

This medication should not be used with Cisapride, Quinidine, Pimozide, Dofetilide or Methadone because there may be very serious (possibly fatal) problems in the heart rhythm.

Neither with Efavirenz, Isoniazide, Nevirapine, Nifamycins (such as rifabutin) or with medications used to treat seizures (such as phenytoin).

In addition, Itraconazole should not be used with Felodipine, Lovastatin, oral Midazolam, Nisoldipine, Simvastatin or Triazolam, due to a greater chance of suffering serious side effects.

If you are currently using any of these medications, tell your doctor or pharmacist before you start with Itraconazole.

In cases of  overdose

If someone has an overdose and has severe symptoms, such as fainting or difficulty breathing, call emergency immediately.

Do not share this medicine with others

Itraconazole has been prescribed only for its current condition. Do not use it later to treat or prevent another infection unless your doctor tells you to.

What happens if you are allergic to Itraconazole?

A different medicine might be necessary in this case. Lab tests or medical tests, such as liver function, should be done before you start taking this medicine and while you are taking it.

Did you forget a dose?

If you miss a dose, take it as soon as you remember it. However, if it is close to the time of the next one, skip the missed dose.

Take your next dose at the usual time, do not duplicate it to catch up.

Where to store Itraconazole?

  • It should be kept in a room at room temperature, away from light and moisture.
  • Do not store in the bathroom.
  • Keep all medications out of the reach of children and pets.
  • Do not throw medicines into the toilet or pour them into the drain unless instructed to do so.
  • Discard this product correctly when it has expired or is no longer necessary.