Description: Posaconazole is an antifungal that kills the fungi by interfering with the formation of the fungal cell membrane.  Posaconazole has activity against Candida spp.,Aspergillus spp., Coccidioides immitis, Fonsecaea pedrosoi, and some species of Fusarium and zygomycetes.
Absorption: Slowly absorbed from the GI tract. Absorption may be increased w/ food. Time to peak plasma concentration: Approx 5 hr.
Distribution: Plasma protein binding: >98%.
Metabolism: Not significantly metabolised; approx 15-17% is metabolised via hepatic glucuronidation.
Excretion: Mainly via faeces (77%; 66% as unchanged drug); urine (approx 14%, w/ only trace amounts excreted unchanged). Mean elimination half-life: 35 hr.

Posaconazole is an azole antifungal medication. It is used to prevent certain fungal infections in patients who have severely weakened immune systems (e.g., after chemotherapy). It is also used to treat fungal infections in the mouth and throat. It works by stopping the growth of fungi.


How to use posaconazole:

Read the Patient Information Leaflet provided by your pharmacist before you start taking posaconazole and each time you get a refill. If you have any questions, consult your doctor or pharmacist.


Take this medication by mouth with a full meal as directed by your doctor. If you cannot take this medication with a full meal, then take it with a liquid nutritional supplement or a carbonated beverage (such as ginger ale). Shake the medication well before using. Measure the medication with the provided dose-measuring spoon to make sure you have the correct dose. Do not use a household spoon.


Tell your doctor if you have severe diarrhea or vomiting. Posaconazole may not work as well.


The dosage and length of treatment is based on your medical condition and response to treatment.


This medication works best when the amount of medicine in your body is kept at a constant level. Therefore, take this drug at evenly spaced intervals. Do not stop taking the medication unless instructed to do so by your doctor.


Tell your doctor if your condition persists or worsens, if you have severe diarrhea/vomiting, or if you cannot take this medication with a full meal or a liquid nutritional supplement.

Pregnancy Risk: Category C (Risk cannot be ruled out)

Nausea, vomiting, diarrhea, headache, abdominal pain, dizziness, trouble sleeping, or stomach upset may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.


Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.


Tell your doctor immediately if any of these unlikely but serious side effects occur:

  • signs of infection (e.g., fever, persistent sore throat),
  • unusual tiredness,
  • weakness,
  • swelling of the ankles/feet,
  • muscle cramps,
  • mental/mood changes,
  • easy bruising/bleeding,
  • vaginal bleeding,
  • shortness of breath,
  • increased thirst/urination.


Seek immediate medical attention if any of these rare but very serious side effects occur: fast/irregular heartbeat, severe dizziness, fainting.


Posaconazole has rarely caused very serious (possibly fatal) liver disease. If you notice any of the following rare but very serious side effects, stop taking posaconazole and tell your doctor immediately: yellowing eyes/skin, dark urine, persistent nausea/vomiting, severe stomach/abdominal pain.


A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any of the following symptoms of a serious allergic reaction: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.


Posaconazole can commonly cause a mild rash that is usually not serious. However, you may not be able to tell it apart from a rare rash that could be a sign of a severe allergic reaction. Therefore, seek immediate medical attention if you develop any rash.


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



Before taking posaconazole, tell your doctor or pharmacist if you are allergic to it; or to other azole antifungals (e.g., ketoconazole); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.


Before using this medication, tell your doctor or pharmacist your medical history, especially of: liver disease, kidney disease.


Posaconazole may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can infrequently result in serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.


The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using posaconazole, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).


Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/”water pills”) or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using posaconazole safely.


This drug may make you dizzy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Avoid alcoholic beverages because they can increase the effects of dizziness and also increase the risk of serious liver problems.


Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).


Older adults may be more sensitive to the side effects of this drug, especially QT prolongation (see above).


During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.


It is not known whether this drug passes into breast milk. Consult your doctor before breast-feeding.




Many drugs besides posaconazole may affect the heart rhythm (QT prolongation), including amiodarone, dronedarone, pimozide, quinidine, cisapride, among others.


Other medications can affect the removal of posaconazole from your body, which may affect how posaconazole works. Examples include cimetidine, efavirenz, proton pump inhibitors (such as esomeprazole, pantoprazole), rifamycins (such as rifabutin), certain drugs used to treat seizures (such as phenytoin), among others.


This drug can slow down the removal of other drugs from your body, which may affect how they work. Examples of affected drugs include certain alpha blockers (such as alfuzosin, silodosin, tamsulosin), ergot alkaloids (such as ergotamine, dihydroergotamine), certain immunosuppressants (such as cyclosporine, sirolimus, tacrolimus), certain benzodiazepines (such as midazolam, triazolam, alprazolam), certain “statin” drugs (such as atorvastatin, simvastatin, lovastatin), avanafil, eletriptan, eplerenone, lurasidone, ranolazine, rivaroxaban, ticagrelor, tolvaptan, among others.



If overdose is suspected, contact a poison control center or emergency room immediately.



Do not share this medication with others.


This medication has been prescribed for your current condition only. Do not use it later to treat or prevent another infection unless told to do so by your doctor. A different medication may be necessary in that case.


Laboratory and/or medical tests (e.g., liver function tests) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.


Missed Dose

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.



Store at room temperature away from light and moisture. Do not freeze. Do not store in the bathroom. Keep all medications away from children and pets.


Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.




Available Brands

Noxafil [ Merck Sharp & Dohme ]

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