The antifungal agent posaconazole is used to treat specific fungal infections that are resistant to other medicines. In medicine, the drug is also called posaconazole.
Posaconazole has been registered in Germany since the end of 2005 under the trade name Noxafil® and was launched by Essex Pharma.
The drug is usually used against fungi that are resistant to common antimycotics such as itraconazole or amphotericin B. The drug is subject to prescription.
Posaconazole belongs to the drug group of triazoles and imidazoles. As with itraconazole and voriconazole, the drug is a synthetic triazole antifungal. Its positive features include its broad spectrum of action, which can also be used for prophylaxis, as well as its good compatibility.
Mushrooms are equipped with a cell wall composed of multiple sugars and the insect armor chitin. The cell membrane of the fungi extends into the interior of the cell and forms part of the cell wall. It contains the important substance ergosterol. In this construction, there is a serious difference between the fungal cell membrane and the human cell membrane. In that there is cholesterol.
The ergosterol, which is extremely important for the cell membrane of fungi, is formed step by step from the substance squalene. At this point, posaconazole unfolds its effect. The antifungal substance has the ability to inhibit the third step of converting squalene by blocking an enzyme necessary for it. In this case, instead of the required ergosterol false building materials. In the further course, the wrong building materials within the cell membrane cause a disturbance of the metabolic processes, which are important for the mushroom proliferation. Although the fungi of posaconazole are not killed, they can no longer multiply undisturbed.
Posaconazole is used to treat various fungal infections. However, the antimycotic usually does not belong to the means of first choice. Only when other treatments are unsuccessful will posaconazole be used.
Indications for posaconazole include Aspergillus fungi that have invaded the patient's body and can not be effectively treated by the administration of itraconazole or amphotericin B. There is also the possibility that the patient does not tolerate these agents.
Further indications are mycetomas (soft tissue tumors), which consist of fungal tissue, as well as mold infections, which can not be successfully treated with itraconazole. The same applies to fusarioses (ascomycete infections) whose treatment with amphotericin B is not possible.
In addition, posaconazole is suitable for the treatment of parasites such as coccidia. These are unicellular organisms in body cells which are insensitive to antifungals such as fluconazole, itraconazole or amphotericin B.
Posaconazole is used as a first-line treatment for the treatment of fungal infections in the mouth and throat. This is especially true for people whose immune system is compromised or who have a serious illness.
Furthermore, a prophylactic use of posaconazole is possible to protect certain groups of people from fungal infections. These are patients suffering from blood cancer or acute myeloid leukemia who undergo chemotherapy. Because there is a permanent shortage of neutrophils in the blood, there is a risk that the affected people contract aggressive fungal infections.
The same applies to recipients of bone marrow donations. So their defense system must be suppressed to counteract a rejection of the donor bone marrow.
Posaconazole is usually administered orally through tablets. Together with food, the patient takes 400 milligrams of the drug twice a day.
The use of posaconazole may in some cases result in unwanted side effects. The patients often suffer from nausea, vomiting, loss of appetite, which sometimes leads to refusal to eat, dizziness, taste disorders, headache, abdominal pain, drowsiness, constipation, flatulence, anal discomfort, dry mouth, feelings of weakness, itching, rash and fever.
Disorders of the mineral balance, a lack of neutrophils, a lack of magnesium and potassium and hypertension are not uncommon. There may also be occasional tremors, anemia, cardiac arrhythmias, convulsions, hiccups, cough, hepatitis, jaundice, mouth ulcers, hair loss, and confusion.
Posaconazole should not be used if the patient is hypersensitive to the drug. Consistent consideration of the risk and benefit of the physician is also required if the patient suffers from hypersensitivity to other triazoles and imidazoles, or has liver dysfunction, cardiac arrhythmia, and severe diarrhea.
Animal studies during pregnancy revealed a dangerous effect of posaconazole on the unborn child. How high the risk in humans fails, could not be determined. For this reason, childbearing women are advised to consistently prevent during posaconazole treatment. In pregnancy, the antifungal drug is administered only when the doctor estimates the benefit to the patient higher than the risk to the baby. During lactation, the mother has to abstain from posaconazole therapy.
There are intensive interactions between posaconazole and many other medications. Therefore, the antifungal should not be co-administered with benzodiazepines such as alprazolam, midazolam and triazolam, anticonvulsants such as carbamazepine, primidone, phenytoin and phenobarbital, tuberculosis agents such as rifabutin and rifampecin or H1-anithistaminics such as astemizole or terfenadine. The same applies to ergot alkaloids such as dihydroergotamine and ergotamine, cytotoxic drugs such as vinblastine and vincristine and the gastric agent cisapride. Tags: