Vfend (Voriconazole) Dosage and Side Effects
VFEND is prescribed by your doctor to treat certain fungal infections, specifically Aspergillus or Candida infections.
Warnings and Precautions
Serious Warnings and Precautions
- Some medications should not be taken during VFEND treatment (see listing under “Interactions with This Medication:”)
- VFEND may cause irregular heartbeat and rarely cardiac arrest and death
- VFEND may cause disturbances in vision
- VFEND may cause liver problems
- VFEND may cause severe skin reactions
- VFEND may cause harm to the fetus in pregnant women
Take special care with VFEND:
Before being treated with VFEND, tell your doctor if:
- you have any of the following conditions: history of heart disease, or an irregular heart beat.
- you have had any drug allergies including allergic reactions to other azoles.
- you are suffering from, or have ever suffered from liver disease.
- you are suffering from, or have ever suffered from kidney disease.
- you are already being treated with certain medication.
- you think you have galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption, please check with your doctor before starting to take VFEND tablets since they contain lactose monohydrate.
- you think you have sucrose intolerance, fructose intolerance, sucrase-isomaltase deficiency or glucose-galactose malabsorption, please check with your doctor before starting to take VFEND powder for oral suspension since it contains sucrose.
- you are pregnant: VFEND must not be taken during pregnancy, unless indicated by your doctor. Effective contraception must be used in women of child-bearing potential. Contact your doctor immediately if you become pregnant while taking VFEND.
- you are breast-feeding: VFEND must not be taken during breast-feeding. Ask your doctor or pharmacist for advice before taking any medicine while breast-feeding.
While being treated with VFEND:
- tell your doctor immediately if you develop a severe skin rash or blisters.
- strong sunlight should be avoided while being treated with VFEND. Tell your doctor if you develop an increased sensitivity of skin to the sun.
- your doctor may wish to monitor the function of your liver and kidney by doing blood tests.
Like all medicines, VFEND can have side effects. If any side effects occur, most are likely to be minor and temporary. However, some may be serious and need medical attention.
The most commonly reported side effects are visual disturbances (blurring of vision, reduced vision, colour vision change and increased sensitivity to light), fever, rash, nausea, vomiting, diarrhea, headache, swelling of the extremities and stomach pains.
Other reported side effects include: changes in heart rate or rhythm, changes in blood pressure, blood cell changes, blood chemistry changes, dizziness, itchiness, weakness, back pain, chest pain, flu like symptoms, facial swelling, hallucinations and other nervous symptoms, tingling, cough, breathing difficulty, hair loss, pain and irritation of the eyes, joint pain.
The following side effects have also been reported with the use of VFEND: peripheral neuropathy (nerve damage) with symptoms such as a burning pain, tingling, numbness, sensitivity to touch and weakness, and hyponatremia (low levels of sodium in the blood) with symptoms such as nausea, vomiting, confusion, weakness, fatigue, cramps, decreased consciousness and seizures.
Check with your doctor immediately if chills, fever, flushing, sweating, muscle aches or pains, or other fIu-like symptoms occur, especially if they occur shortly before, or together with a skin rash. Also, contact your doctor in case of a fast heartbeat, chest tightness or faintness. Very rarely, these effects may be the first signs of a serious reaction to this medication.
Contact your doctor if you suffer persistent abdominal pain and tenderness or vomiting as this may be a sign of a serious condition (pancreatitis).
If you develop bone pain during treatment, contact your doctor.
Driving and using machines:
VFEND may cause changes to vision, including blurring and/or photophobia (sensitivity to light). The majority of visual symptoms appeared to spontaneously resolve within 60 minutes. While being treated with VFEND you must avoid potentially hazardous tasks, such as driving or operating machinery if you perceive any change in vision. You should not drive at night while taking VFEND.
Interactions with this medication
Taking other medicines with VFEND:
It is very important that you inform your doctor or pharmacist if you are taking or have taken any other medicines, even those that are obtained without a prescription. Some medicines affect the way VFEND works and dosage adjustments or monitoring may be necessary, such as for the following:
- Cyclosporine (a medicine used in transplant patients)
- Tacrolimus (a medicine used in transplant patients)
- Tricyclic antidepressants
- Antiarrhythmics (drugs that stabilize heart function such as procainamide, amiodarone, quinidine, sotalol)
- Antipsychotic drugs
- HIV protease inhibitors
- Macrolide antibiotics
- Oral contraceptives
- Short-acting opiates (e.g. alfentanil, sufentanil)
- Long-acting opiates (e.g. oxycodone, fentanyl)
- Some oral anticoagulants (e.g. warfarin, coumarin)
- Fluconazole (used for fungal infections)
- Everolimus (used for treating advanced kidney cancer and in transplant patients)
- Benzodiazepines (e.g. midazolam, triazolam, alprazolam)
- Calcium channel blockers (heart medications)
- Sulfonylureas (e.g. glyburide, glipizide)
Tell your doctor if you are taking non-steroidal anti-inflammatories (NSAIDs) (used for treating pain and inflammation) including ibuprofen and diclofenac, as the NSAID dose may have to be adjusted.
The following list of medicines must not be taken during your course of VFEND treatment:
- Terfenadine* (a medicine for allergy)
- Astemizole* (a medicine for allergy)
- Cisapride* (a medicine for stomach problems)
- Pimozide (a medicine for treating mental illness)
- Quinidine (a medicine for irregular heart beat)
- Rifampicin (a medicine for treating tuberculosis)
- Carbamazepine (a medicine used to treat seizures)
- Long-acting barbiturates (medicines for severe insomnia and seizures) such as phenobarbital
- Sirolimus (used in transplant patients)
- Rifabutin (a medicine for fungal infections)
- Ergot Alkaloids: ergotamine and dihydroergotamine (a medicine for migraines)
- Ritonavir (doses of 400mg twice daily or higher) and efavirenz (doses of 400mg once daily or higher) (medicines for the treatment of HIV)
- St. John's wort (Hypericum perforatum)
Proper Use of this medication
Usual adult dose:
Your doctor will determine your dose depending on your weight and the type of infection (or suspected infection) you have.
Always take VFEND exactly as directed by your doctor. You should check with your doctor or pharmacist if you are unsure. Never change the dose yourself.
Your doctor will prescribe a higher dose of VFEND on your first day of treatment to more quickly obtain an effective blood level of the antibiotic in your body.
During the first 24 hours, you will be administered 2 doses of 6 mg/kg (12 hours apart).
After the first 24 hours:
- If you have an Aspergillus infection, you will be administered 4 mg/kg, twice a day.
- If you have a Candida infection, you will be administered 3 mg/kg or 4 mg/kg, twice a day.
It has been shown that taking all doses at the appropriate times may greatly increase the effectiveness of your medicine.
VFEND tablets must be taken at least one hour before or two hours after a meal. Swallow the tablet whole with some water.
VFEND oral suspension must be taken one hour before or following a meal. Shake the closed bottle for approximately 10 seconds before each use. The suspension should only be administered using the oral dispenser supplied with each pack.
VFEND oral suspension should not be mixed with any other medication or flavoring agent, and should not be further diluted with water or any other drinks.
If you have liver disease, your doctor may prescribe a lower dose of VFEND.
Your doctor may order periodic blood tests to monitor your liver function during VFEND treatment.
Continue taking VFEND until your doctor tells you to stop. Do not stop treatment early because your infection may not be cured. Patients with a weakened immune system or those with difficult infections may require long term treatment to prevent the infection from returning.
In case of drug overdose, contact a health care practitioner, hospital emergency department or regional Poison Control Centre immediately, even if there are no symptoms.
Take your box of VFEND tablets or bottle of VFEND oral suspension with you.
If you miss taking a dose of VFEND, just take the next dose when it is due. Do not take a double dose to make up for the forgotten dose.
Other related products
The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.