Flucytosine (Oral Route) Description and Brand Names

Description and Brand Names

Drug information provided by: Merative, Micromedex®

US Brand Name

Ancobon

Descriptions

Flucytosine is used in combination with other medicine (eg, amphotericin B) to treat serious fungus infections, including Candida infections (eg, septicemia, endocarditis, urinary tract infections) or Cryptococcus infections (eg, meningitis, lung infections). This medicine works by killing the fungus or preventing its growth.

This medicine is available only with your doctor's prescription.

This product is available in the following dosage forms:

Capsule

Before Using

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies have not been performed on the relationship of age to the effects of flucytosine in the pediatric population. Safety and efficacy have not been established.

Geriatric

No information is available on the relationship of age to the effects of flucytosine in geriatric patients.

Breastfeeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Drug Interactions

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

Levomethadyl
Tegafur

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Zidovudine

Other Interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Proper Use

Take this medicine exactly as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. To do so may increase the chance of side effects.

Keep using this medicine for the full treatment time, even if you feel better after the first few doses. Your infection may not clear up if you stop using the medicine too soon.

Swallow one capsule at a time over a 15 minute period to help prevent nausea and vomiting.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

For oral dosage form (capsules):
- For fungus infections:
  - Adults—Dose is based on body weight and must be determined by your doctor. The dose is usually 50 to 150 milligrams (mg) per kilogram (kg) of body weight per day, taken every 6 hours.
  - Children—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Precautions

It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.

Do not take other medicines unless thy have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Incidence not known

Agitation
black, bloody, tarry stools
blistering, peeling, or loosening of the skin
bloody or cloudy urine
burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
burning upper abdominal or stomach pain
change in consciousness
chest pain or tightness
chills
confusion
cough or hoarseness
dark urine
decreased urine output
depression
diarrhea
dizziness
dry mouth
feeling of constant movement of self or surroundings
fever
headache
hearing loss
hives, itching, skin rash
increased sensitivity of the skin to sunlight
irregular heartbeat
irritability
joint or muscle pain
light-colored stools
loss of appetite
loss of consciousness
lower back or side pain
mood changes
muscle cramps or twitching
nausea
no blood pressure or pulse
no breathing
numbness or tingling in the hands, feet, or lips
painful or difficult urination
pain in the lower back or side
pale skin
rapid weight gain
rectal bleeding
red irritated eyes
red skin lesions, often with a purple center
redness of the skin
seeing, hearing, or feeling things that are not there
seizures
sensation of spinning
severe sunburn
shakiness and unsteady walk
sore throat
sores, ulcers, or white spots on the lips or in the mouth
stopping of the heart
swelling of the face, ankles, or hands
swollen glands
thirst
trouble breathing
unpleasant breath odor
unsteadiness, trembling, or other problems with muscle control or coordination
unusual bleeding or bruising
unusual drowsiness, dullness, tiredness, weakness or feeling of sluggishness
vomiting
vomiting of blood or material that looks like coffee grounds
weakness in the arms, hands, legs, or feet
weight loss
yellow eyes or skin

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Portions of this document last updated: Feb. 01, 2024

Original article: https://www.mayoclinic.org/drugs-supplements/flucytosine-oral-route/description/DRG-20063847

Flucytosine (Oral Route)