Gris-PEG (Oral)
Generic name: griseofulvin [ gris-ee-oh-FUL-vin ]
Brand names: Fulvicin P/G, Fulvicin-U/F, Grifulvin V, Gris-PEG
Drug class: Miscellaneous antifungals
Medically reviewed by Drugs.com. Last updated on Mar 21, 2024.
Uses for Gris-PEG
Griseofulvin belongs to the group of medicines called antifungals. It is used to treat fungus infections of the body, feet, groin and thighs, scalp, skin, fingernails, and toenails. This medicine may be taken alone or used along with medicines that are applied to the skin for fungus infections.
Use of griseofulvin for prevention of fungus infection have not been established.
This medicine is available only with your doctor's prescription.
Before using Gris-PEG
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 performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of griseofulvin in children. However, safety and efficacy have not been established in children up to 2 years of age.
Geriatric
No information is available on the relationship of age to the effects of griseofulvin in geriatric patients.
Breast Feeding
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.
Interactions with Medicines
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 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.
- Desogestrel
- Dienogest
- Drospirenone
- Estradiol
- Ethinyl Estradiol
- Ethynodiol
- Etonogestrel
- Gestodene
- Levoketoconazole
- Levonorgestrel
- Medroxyprogesterone
- Mestranol
- Methotrexate
- Nomegestrol
- Norelgestromin
- Norethindrone
- Norgestimate
- Norgestrel
- Porfimer
- Segesterone
- Ulipristal
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Aminolevulinic Acid
- Phenobarbital
- Warfarin
Interactions with Food/Tobacco/Alcohol
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. 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 is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco.
- Ethanol
Other Medical Problems
The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:
- Actinomycosis (bacterial infection) or
- Blastomycosis (Gilchrist’s disease) or
- Candidiasis (yeast infection) or
- Histoplasmosis (Darling’s disease) or
- Other infections (e.g., bacteria) or
- Sporotrichosis (Rose gardener's disease) or
- Tinea versicolor (Tinea flava)—Griseofulvin will not work in patients with these conditions.
- Liver failure or
- Porphyria (enzyme problem)—Should not be used in patients with these conditions.
- Lupus erythematosus or lupus-like diseases—Use with caution. May make this condition worse.
Proper use of Gris-PEG
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.
Keep yourself clean to help control infection and prevent reinfection.
Griseofulvin is absorbed best when it is taken with a high fat meal, such as a cheeseburger, whole milk, or ice cream. Tell your doctor if you are on a low-fat diet.
Griseofulvin is best taken with or after meals, especially fatty ones (e.g., whole milk or ice cream). This lessens possible stomach upset and helps to clear up the infection by helping your body absorb the medicine better. However, if you are on a low-fat diet, check with your doctor.
For patients taking the oral liquid:
- Use a specially marked measuring spoon or other device to measure each dose accurately. The average household teaspoon may not hold the right amount of liquid.
You may swallow the tablets whole or sprinkle the crushed tablets in one tablespoonful of applesauce. Swallow it immediately without chewing.
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 forms (microsize capsules, tablets, or suspension):
- Treatment of fungus infections of the feet and nails:
- Adults and teenagers—500 milligrams (mg) every 12 hours.
- Children—Dose is based on body weight and must be determined by your doctor. The usual dose is 5 milligrams (mg) per kilogram (kg) (2.3 mg per pound) of body weight every 12 hours, or 10 milligrams (mg) per kilogram (kg) (4.6 mg per pound) of body weight once a day.
- Treatment of fungus infections of the scalp, skin, and groin:
- Adults and teenagers—250 milligrams (mg) every 12 hours or 500 mg once a day.
- Children—Dose is based on body weight and must be determined by your doctor. The usual dose is 5 milligrams (mg) per kilogram (kg) (2.3 mg per pound) of body weight every 12 hours, or 10 milligrams (mg) per kilogram (kg) (4.6 mg per pound) of body weight once a day.
- Treatment of fungus infections of the feet and nails:
- For oral dosage form (ultramicrosize tablets):
- Treatment of fungus infections:
- Adults—375 milligrams (mg) per day, taken as a single dose or divided in small doses. Some patients may need 750 mg divided in small doses.
- Children 3 years of age and older weighing over 60 pounds—Dose is based on body weight and must be determined by your doctor. The usual dose is 187.5 to 375 mg per day.
- Children 3 years of age and older weighing 35 to 60 pounds—Dose is based on body weight and must be determined by your doctor. The usual dose is 125 to 187.5 mg per day.
- Children up to 2 years of age—Use and dose must be determined by your doctor.
- Treatment of fungus infections:
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.
Related/similar drugs
clotrimazole topical, ketoconazole topical, terbinafine, itraconazole, miconazole topical, ciclopirox topical, Lamisil, Jublia, griseofulvin, Penlac
Precautions while using Gris-PEG
It is very important that your doctor should check the progress of you or your child at regular visits to make sure that this medicine is working properly and to check for unwanted effects.
If your symptoms do not improve, or if they become worse, check with your doctor. You may need to take this medicine for several weeks or months before your infection gets better.
Using this medicine while you are pregnant may cause serious unwanted effects in your newborn baby. Tell your doctor right away if you think you are pregnant or if you plan to become pregnant while using this medicine.
Serious skin reactions can occur with this medicine. Stop using this medicine and check with your doctor right away if you or your child have blistering, peeling, or loosening of the skin; red skin lesions; severe acne or skin rash; sores or ulcers on the skin; or fever or chills while you are using this medicine.
Stop using this medicine and check with your doctor right away if you or your child have pain or tenderness in the upper stomach; pale stools; dark urine; loss of appetite; nausea; unusual tiredness or weakness; or yellow eyes or skin. These could be symptoms of a serious liver problem.
Griseofulvin has been shown to cause liver and thyroid tumors in some animals. You and your doctor should discuss the good this medicine will do, as well as the risks of taking it.
Birth control pills containing estrogen may not work properly if you take them while you are taking griseofulvin. Unplanned pregnancies may occur. To keep from getting pregnant, use another form of birth control for up to 1 month after your last treatment. Other forms of birth control include condoms, diaphragms, or contraceptive foams or jellies.
Griseofulvin may increase the effects of alcohol. If taken with alcohol it may also cause fast heartbeat, flushing, increased sweating, or redness of the face. If you have these symptoms, do not drink alcoholic beverages while you are taking this medicine, unless you have checked first with your doctor.
This medicine may cause some people to become dizzy, drowsy, or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do other things that could be dangerous if you are dizzy or are not alert. If these reactions are especially bothersome, check with your doctor.
Griseofulvin may cause your skin to be more sensitive to sunlight than it is normally. Exposure to sunlight, even for brief periods of time, may cause a skin rash, itching, redness or other discoloration of the skin, or a severe sunburn. When you begin taking this medicine:
- Stay out of direct sunlight, especially between the hours of 10:00 a.m. and 3:00 p.m., if possible.
- Wear protective clothing, including a hat. Also, wear sunglasses.
- Apply a sun block product that has a skin protection factor (SPF) of at least 15. Some patients may require a product with a higher SPF number, especially if they have a fair complexion. If you have any questions about this, check with your doctor.
- Apply a sun block lipstick that has an SPF of at least 15 to protect your lips.
- Do not use a sunlamp or tanning bed or booth.
If you have a severe reaction from the sun, check with your doctor.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.
Side Effects of Gris-PEG
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:
More common
- Blistering, peeling, or loosening of the skin
- chills
- cough
- diarrhea
- fever
- itching
- joint or muscle pain
- red, irritated eyes
- sore throat
- sores, ulcers, or white spots in the mouth or on the lips
- unusual tiredness or weakness
Less common
- Confusion
- increased sensitivity of the skin to sunlight
- skin rash, hives, or itching
- soreness or irritation of the mouth or tongue
Rare
- Black, tarry stools
- chest pain
- cloudy urine
- large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
- numbness, tingling, pain, or weakness in the hands or feet
- painful or difficult urination
- shortness of breath
- swollen glands
- unusual bleeding or bruising
- yellow eyes or skin
Incidence not known
- Abdominal or stomach pain
- burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
- clay-colored stools
- dark urine
- dizziness
- headache
- loss of appetite
- nausea
- unpleasant breath odor
- vomiting of blood
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
More common
- Hives or welts
- redness of the skin
Less common
- Trouble with sleeping
Incidence not known
- Heartburn
- pain or discomfort in the chest, upper stomach, or throat
- sleeplessness
- unable to sleep
- white patches in the mouth or throat or on the tongue
- white patches with diaper rash
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.
Commonly used brand name(s)
In the U.S.
- Fulvicin P/G
- Fulvicin-U/F
- Grifulvin V
- Gris-PEG
Available Dosage Forms:
- Tablet
- Suspension
Therapeutic Class: Antifungal
More about Gris-PEG (griseofulvin)
- Check interactions
- Compare alternatives
- Reviews (5)
- Drug images
- Side effects
- Dosage information
- During pregnancy
- Generic availability
- Drug class: miscellaneous antifungals
Patient resources
Other brands
Grifulvin V, Fulvicin P/G, Fulvicin U/F
Professional resources
Related treatment guides
Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.