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Gris-PEG (Oral)

Generic name: griseofulvin

Brand names: Fulvicin P/G, Fulvicin-U/F, Grifulvin V, Gris-PEG

Last updated November 12, 2025 0 views
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Uses for Gris-PEG

Griseofulvin is part of a group of medicines known as antifungals. It is used to treat fungal infections in the body, feet, groin and thighs, scalp, skin, fingernails, and toenails. You can take this medicine by itself or together with medicines that are applied to the skin for fungal infections.

The use of griseofulvin to prevent fungal infections has not been proven.

This medicine is available only with a prescription from your doctor.

This section was rewritten for readability and reviewed for meaning.

Precautions while using Gris-PEG

It is very important that your doctor checks your progress or your child's progress at regular visits to ensure that this medicine is working properly and to check for any unwanted effects.

If your symptoms do not improve, or if they get worse, talk to your doctor. You might need to take this medicine for several weeks or months before your infection improves.

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 happen with this medicine. Stop using this medicine and check with your doctor immediately 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 using this medicine.

Stop using this medicine and check with your doctor immediately if you or your child experience 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 may be signs 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 benefits of this medicine, as well as the risks of taking it.

Birth control pills containing estrogen may not work properly while you are taking griseofulvin. Unplanned pregnancies may occur. To prevent pregnancy, 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 taking this medicine, unless you have checked with your doctor first.

This medicine may cause some people to feel dizzy, drowsy, or less alert than usual. Make sure you know how you react to this medicine before driving, using machines, or doing other activities that could be dangerous if you are dizzy or not alert. If these effects are especially bothersome, consult your doctor.

Griseofulvin may make your skin more sensitive to sunlight than usual. Even brief exposure to sunlight may cause a skin rash, itching, redness or other discoloration of the skin, or a severe sunburn. When you start taking this medicine:

  • Stay out of direct sunlight, especially between 10:00 a.m. and 3:00 p.m., if possible.
  • Wear protective clothing, including a hat. Also, wear sunglasses.
  • Use a sunblock product with a skin protection factor (SPF) of at least 15. Some patients may need a product with a higher SPF, especially if they have fair skin. If you have questions about this, ask your doctor.
  • Use a sunblock lipstick with 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, talk to your doctor.

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

This section was rewritten for readability and reviewed for meaning.

Before using Gris-PEG

In deciding to use a medicine, you and your doctor will need to weigh the risks against the benefits of the medicine. Here are some important points to consider for this medicine:

Allergies

Inform your doctor if you have ever had any unusual or allergic reactions to this medicine or any other medicines. Also, let your healthcare professional know if you have other allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, carefully read the label or package ingredients.

Pediatric

Studies have not shown any specific problems that would limit the use of griseofulvin in children. However, safety and effectiveness have not been confirmed in children under 2 years old.

Geriatric

There is no information available about how age affects the effects of griseofulvin in older patients.

Breast Feeding

There are no adequate studies in women to determine the risk to infants when using this medicine during breastfeeding. Consider the possible benefits and risks before taking this medicine while breastfeeding.

Interactions with Medicines

While some medicines should not be used together at all, others may be used together even if an interaction could happen. In these situations, your doctor may adjust the dose or take other precautions. It is particularly important for your healthcare professional to know if you are taking any of the medicines listed below. The following interactions are significant but may not include all possible interactions.

Using this medicine with any of the following medicines is usually not recommended, but may be necessary in some cases. If both medicines are prescribed together, your doctor may change the dose or frequency of one or both 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 raise the risk of certain side effects, but using both drugs might be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or frequency of one or both medicines.

  • Aminolevulinic Acid
  • Phenobarbital
  • Warfarin

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be taken around the time of eating food or certain types of food due to possible interactions. Using alcohol or tobacco with certain medicines may also lead to interactions. The following interactions are significant but may not include all possible interactions.

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 frequency of this medicine, or provide special instructions regarding food, alcohol, or tobacco.

  • Ethanol

Other Medical Problems

Other medical issues may influence the use of this medicine. Be sure to inform 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 be effective 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. This may worsen the condition.

This section was rewritten for readability and reviewed for meaning.

Side Effects of Gris-PEG

Along with its necessary effects, a medicine may cause some unwanted effects. Not all of these side effects may occur, but if they do, they may require 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 gets used to the medicine. Your health care professional may also 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.

In the U.S.

  • Fulvicin P/G
  • Fulvicin-U/F
  • Grifulvin V
  • Gris-PEG

Available Dosage Forms:

  • Tablet
  • Suspension

Therapeutic Class: Antifungal

This section was rewritten for readability and reviewed for meaning.

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.
  • 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.

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 medicines

Before you take this medicine: the information on this page is general and may not cover your personal circumstances. Read the label supplied with your medicine and ask a pharmacist or doctor if you are unsure, especially if you are pregnant, breastfeeding, taking other medicines or managing a long-term condition.
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