The systemic antifungal drug itraconazole is used to treat fungal diseases. The drug can be administered both orally and intravenously.
What is itraconazole?
The systemic antifungal drug itraconazole is used to treat fungal diseases. The drug can be administered both orally and intravenously. Itraconazole is the name given to an active substance belonging to the triazole antifungal group. It is used for the treatment of fungal infections caused by various pathogens. These include dermatophytes (filamentous fungi), molds and yeasts. In Europe, itraconazole has been approved since the early 1990s. The antifungal is available as an oral solution and in capsule form. The active ingredient represents a mixture of four diastereomers. Itraconazole, like other antifungals, has the property of acting exclusively against certain types of fungi. In Germany, the antifungal agent is subject to prescription.
Pharmacological effect
Itraconazole is a member of the group of triazoles and imidazoles. The positive effect of the active substance is based on the fact that it inhibits the growth of fungi. In this way, it prevents their multiplication, which physicians call fungistatic effect. Itraconazole belongs to the more modern triazoles and imidazoles. As a result, the antifungal agent has certain advantages over older preparations such as ketoconazole. The duration of action of itraconazole is longer than that of ketoconazole. In addition, the liver-damaging side effects of the drug are significantly lower. The antifungal effect of the drug is achieved by reducing ergosterol synthesis within the fungal cells. Ergosterol forms a component of the cell membrane that is essential for survival. Itraconazole is considered effective against fungal species such as yeasts, which include Candida albicans and Cryptococcus neoformans, dermatophytes such as Epidermophyton floccosum, Histoplasma spp., Aspergillus spp., Sporothrix schenckii, Blastomyces dermatidis, Fonsecaea spp., Cladosporium spp. and Paracoccidioides brasiliensis. In contrast, the antifungal agent is ineffective against fungal species such as Fusarium spp, Zygomycota, Scopulariopsis spp, and Scedosporium spp. The half-life of itraconazole depends on the dose as well as the duration of drug intake. In the case of a single administration of 100 milligrams, it is 15 hours. In the case of a single dose of 400 milligrams, the half-life is 25 hours, and in the case of 400 milligrams of itraconazole a day over a 14-day period, the half-life is 42 hours. Most of the absorption of the antifungal drug occurs within the intestine.
Medicinal use and application
Itraconazole is administered for the treatment of various fungal infections on the skin. These can be fungal skin infections caused by dermatophytes, corneal infections caused by molds, yeast infections, or Kleienpilzflechte. Furthermore, itraconazole can be used to treat fungal infections of the vagina if these are caused by yeasts and the use of other active substances has not achieved therapeutic success. Furthermore, onychomycoses (fungal infections of the nails) can be treated with the help of itraconazole. Systemic fungal diseases are another area of application for the antifungal agent. In this case, the harmful pathogens spread throughout the organism via the bloodstream. In people who have undergone bone marrow transplantation or who suffer from diseases of blood-forming bone marrow cells, the prophylactic use of itraconazole can prevent the development of mycosis. A typical mycosis is, for example, thrush. In this case, the mouth and throat are infected with yeast fungi. However, patients suffering from AIDS or who have to take immunosuppressants can also benefit from the administration of itraconazole. Itraconazole is also used when standard treatment of fungal infections caused by cryptococcal yeast fungi with drugs such as flucytosine or amphotericin B is unsuccessful. These diseases predominantly affect the spinal cord and brain. Itraconazole can be administered orally or intravenously. As a rule, the antimycotic is administered in the form of capsules. Their intake takes place once or twice a day immediately after a meal.
Risks and side effects
Taking itraconazole may result in unwanted side effects. However, these side effects do not automatically occur in every patient.Most often they manifest themselves in the form of flatulence, abdominal pain, diarrhea, nausea, headache, rhinitis, a sinus infection (sinusitis), respiratory infections or skin rash. Rather rarely, side effects include serum sickness, platelet deficiency, blood potassium deficiency, nervous dysfunction, white blood cell deficiency, visual disturbances such as double vision, dizziness, hearing loss, ringing in the ears, pulmonary edema, Stevens-Johnson syndrome, hair loss, hives, itching, photosensitivity, frequent urination, erectile dysfunction, menstrual irregularities, and muscle and joint pain. There are also some contraindications to itraconazole. For example, the patient must not suffer from hypersensitivity to the antifungal drug. In addition, many active ingredients are broken down more slowly in the liver when itraconazole is taken. This can lead to increased side effects. For this reason, itraconazole should 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 liver or kidney function disorders, taking itraconazole may further worsen his condition. For this reason, the drug must be administered under strict medical supervision. During pregnancy, the use of itraconazole should be avoided. Exceptions are allowed only if the mother is in danger of death. Even in children, the administration of the antifungal agent is considered permissible only in exceptional cases. The simultaneous administration of itraconazole and drugs such as rifabutin, phenytoin or rifampicin should be avoided, as these preparations weaken the positive effect of the antifungal drug. The administration of erythromycin, clarithromycin, ritonavir and indinavir, on the other hand, increases the effect and side effects of itraconazole. Because antacids (acid-binding agents) reduce itraconazole absorption into the body, it is advisable to take them two hours later.
