Itraconazole

The systemic antifungal agent Itraconazole is used against fungal diseases. The drug can be administered both orally and intravenously.

What is itraconazole?

Itraconazole is an active ingredient that belongs to the group of triazole antimycotics. It is used to treat fungal infections caused by various pathogens. These include a. Dermatophytes (thread fungi), molds and yeasts.

Itraconazole has been approved in Europe since the early 1990s. The antifungal is offered as an oral solution and in capsule form. The active ingredient is a mixture of four diastereomers. Itraconazole, like other antimycotics, only works against certain types of fungus. In Germany, the antifungal agent is subject to prescription.

Pharmacological effect

Itraconazole belongs to the group of triazoles and imidazoles. The positive effect of the active ingredient is based on the fact that it inhibits the growth of fungi. In this way, it prevents them from multiplying, which doctors call a fungistatic effect.

Itraconazole is counted among the more modern representatives of the triazoles and imidazoles. As a result, the anti-fungal agent has certain advantages over older preparations such as ketoconazole. Itraconazole lasts longer than ketoconazole. In addition, the liver-damaging side effects of the drug are significantly lower.

The antifungal effect of the agent is achieved by reducing the ergosterol synthesis within the fungal cells. The ergosterol forms a vital component of the cell membrane. Itraconazole is considered effective against types of fungi such as yeasts, to which u. a. Candida albicans and Cryptococcus neoformans, dermatophytes such as Epidermophyton floccosum, Histoplasma spp., Aspergillus spp., Sporothrixschenckii, Blastomyces dermatidis, Fonsecaea spp., Cladosporium spp. as well as Paracoccidioides brasiliensis.

Against fungal species such as Fusarium spp., Zygomycota, Scopulariopsis spp. and Scedosporium spp. the antifungal agent is ineffective.

The half-life of itraconazole depends on the dose and how long the drug was taken. In the case of a single dose of 100 milligrams, it is 15 hours. With a single dose of 400 milligrams, the half-life is 25 hours and with 400 milligrams of itraconazole per day over a period of 14 days, the half-life is 42 hours.Most of the antifungal agent is absorbed within the intestine.

Medical application & use

Itraconazole is administered for the treatment of various fungal infections on the skin. These can be fungal skin diseases caused by dermatophytes, corneal inflammation caused by mold, yeast infections or bran fungus. Itraconazole can also be used to treat fungal infections of the vagina if these are caused by yeast and the use of other active ingredients has not achieved any therapeutic success. Onychomycoses (fungal infections on the nails) can also be treated with itraconazole.

Another area of ​​application for the anti-fungal agent is systemic fungal diseases. The harmful pathogens spread throughout the organism via the bloodstream. In people who have had a bone marrow transplant or who suffer from diseases of blood-forming bone marrow cells, prophylactic use of itraconazole can prevent the development of mycosis.

A typical mycosis is, for example, thrush. The mouth and throat are infected with yeast. However, patients suffering from AIDS or who have to take immunosuppressants can also benefit from the administration of itraconazole.

Itraconazole is also used when a standard treatment for fungal infections caused by cryptococcal yeast with drugs such as flucytosine or amphotericin B is unsuccessful. These diseases mainly affect the spinal cord and brain.

Itraconazole can be administered orally or intravenously. The antifungal is usually given in the form of capsules. They are taken once or twice a day immediately after a meal.

Risks & side effects

Taking itraconazole can have undesirable side effects. However, these side effects do not automatically occur in every patient. Mostly they show up in the form of flatulence, abdominal pain, diarrhea, nausea, headache, runny nose, a sinus infection (sinusitis), respiratory infections or skin rash.

Side effects such as serum sickness, a lack of blood platelets, a blood potassium deficiency, nervous discomfort, a deficiency of white blood cells, visual disturbances such as double vision, dizziness, hearing loss, ringing in the ears, pulmonary edema, Stevens-Johnson syndrome, hair loss, and hives are rather rare , Itching, sensitivity to light, frequent urination, erectile dysfunction, menstrual disorders, and muscle and joint pain.

There are also some contraindications to itraconazole. The patient must not suffer from hypersensitivity to the antifungal agent. In addition, numerous active substances in the liver are broken down more slowly by taking itraconazole. This can lead to increased side effects. For this reason, itraconazole must not be taken together with mizolastine, astemizole, pimozide, quinidine, terfenadine, dofetilide and cisapride. The same applies to triazolam, lovastatin, midazolam and simvastatin.

If the patient suffers from impaired liver or kidney function, taking itraconazole may make their condition worse. For this reason, the drug must be administered under strict medical supervision.

Itraconazole should not be used during pregnancy. Exceptions are only allowed if the mother is in mortal danger. Even with children, the administration of the antifungal agent is only classified as permissible in exceptional cases.

Simultaneous use of itraconazole and drugs such as rifabutin, phenytoin or rifampicin should be avoided, as these preparations weaken the positive effect of the antifungal agent. The administration of erythromycin, clarithromycin, ritonavir and indinavir, however, increases the effects and side effects of itraconazole.

Because antacids (acid-binding agents) reduce the absorption of itraconazole into the body, it is advisable to take them two hours later.