Furazolidone (Oral)

Furazolidone is used to treat infections caused by bacteria and protozoa. It kills bacteria and protozoa (tiny, one-celled animals). Some protozoa are parasites that can lead to various infections in the body.

Furazolidone is taken by mouth. It works in the intestinal tract to treat cholera, colitis, and/or diarrhea caused by bacteria, as well as giardiasis. This medicine is sometimes used along with other medicines for bacterial infections.

Furazolidone may cause serious side effects when taken with certain foods, drinks, or other medicines. Check with your health care professional for a list of products to avoid.

Furazolidone is available only with your doctor's prescription.

It is important for your doctor to check your progress at regular visits. This is to see if the infection has cleared up completely.

If your symptoms do not improve within a week, or if they get worse, check with your doctor.

Drinking alcoholic beverages or using other alcohol-containing products (such as elixirs, cough syrups, tonics, or alcohol injections) while taking furazolidone may rarely cause issues. These issues can include increased side effects like facial redness, difficulty breathing, fainting, and chest tightness. These side effects usually go away within 24 hours without treatment. However, these effects may still happen if you drink alcohol for up to 4 days after stopping furazolidone. Therefore, you should not drink alcoholic beverages or use other alcohol-containing products while taking furazolidone and for 4 days after stopping it.

Certain foods, drinks, or other medications may cause very serious reactions, like severe high blood pressure, when taken with furazolidone. Aged or fermented foods and drinks often have tyramine or other substances that raise blood pressure. To avoid such reactions, the following measures are recommended:

• Do not eat foods that are high in tyramine (often found in aged or fermented foods for flavor), such as cheeses; yeast or meat extracts; fava or broad bean pods; smoked or pickled meat, poultry, or fish; fermented sausage (bologna, pepperoni, salami, summer sausage) or other fermented meat; or any overripe fruit. If you do not receive a list of these foods, ask your health care professional for one.
• Do not drink alcoholic beverages or alcohol-free or reduced-alcohol beer and wine.
• Do not eat or drink large amounts of caffeine-containing foods or beverages like chocolate, coffee, tea, or cola.
• Do not take any other medications unless approved or prescribed by your doctor. This includes nonprescription (over-the-counter [OTC]) appetite suppressants (diet pills) or medications for colds, sinus issues, or allergies.
• Do not consume any of the foods, drinks, or medications listed above for at least 2 weeks after you stop taking furazolidone. They may still interact with this medicine during that period.
• Other foods may also contain tyramine or other substances that increase blood pressure. However, these products usually do not cause serious issues when taken with furazolidone, especially if eaten fresh and in small amounts. These include yogurt, sour cream, cream cheese, cottage cheese, chocolate, and soy sauce. If you have questions about this, ask your health care professional. Also, ask for a list of foods, beverages, or medications that may cause serious problems when taken with furazolidone.

In deciding to use a medicine, the risks of taking the medicine must be weighed against the benefits it will provide. This is a decision you and your doctor will make together. For this medicine, consider the following:

Allergies

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

Pediatric

Since furazolidone may cause anemia, it is not recommended for use in infants up to 1 month old.

Geriatric

Many medicines have not been specifically studied in older adults. Therefore, it may not be known whether they work the same way as they do in younger adults or if they cause different side effects or problems in older adults. There is no specific information comparing the use of furazolidone in elderly patients with use in other age groups.

Breast Feeding

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

Interactions with Medicines

While some 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 situations, your doctor may want to adjust the dose, or other precautions may be necessary. It is especially important that your healthcare professional knows if you are taking any of the medicines listed below when you are using this medicine. The following interactions are selected based on 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.

• Amitriptyline
• Amphetamine
• Apraclonidine
• Benzphetamine
• Brimonidine
• Bupropion
• Carbamazepine
• Carbidopa
• Carbinoxamine
• Clomipramine
• Clovoxamine
• Codeine
• Cyclobenzaprine
• Cyproheptadine
• Desipramine
• Deutetrabenazine
• Dextroamphetamine
• Dextromethorphan
• Diethylpropion
• Doxylamine
• Entacapone
• Femoxetine
• Fenfluramine
• Guanadrel
• Guanethidine
• Hydroxytryptophan
• Imipramine
• Isocarboxazid
• Levodopa
• Levomethadyl
• Lisdexamfetamine
• Maprotiline
• Mazindol
• Meperidine
• Methamphetamine
• Methyldopa
• Mirtazapine
• Nefazodone
• Nefopam
• Nortriptyline
• Opipramol
• Ozanimod
• Phendimetrazine
• Phenmetrazine
• Phentermine
• Phenylalanine
• Pseudoephedrine
• Reserpine
• Safinamide
• Selegiline
• Sertraline
• Sibutramine
• Solriamfetol
• Sumatriptan
• Tetrabenazine
• Tramadol
• Tranylcypromine
• Trimipramine
• Tryptophan
• Venlafaxine
• Viloxazine
• Zimeldine

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 adjust the dose or frequency of use for one or both of the medicines.

• Alfentanil
• Benzhydrocodone
• Butorphanol
• Cholera Vaccine, Live
• Difenoxin
• Dihydrocodeine
• Diphenoxylate
• Dolasetron
• Droperidol
• Epinephrine
• Ethchlorvynol
• Fentanyl
• Frovatriptan
• Granisetron
• Guarana
• Hydrocodone
• Hydromorphone
• Iobenguane I 123
• Iobenguane I 131
• Kava
• Lasmiditan
• Levorphanol
• Licorice
• Lithium
• Lorcaserin
• Ma Huang
• Mate
• Metaraminol
• Metaxalone
• Methadone
• Methylene Blue
• Metoclopramide
• Midodrine
• Morphine
• Morphine Sulfate Liposome
• Naratriptan
• Norepinephrine
• Ondansetron
• Oxycodone
• Oxymetazoline
• Oxymorphone
• Palonosetron
• Pentazocine
• Phenylephrine
• Phenylpropanolamine
• Reboxetine
• Remifentanil
• St John's Wort
• Sufentanil
• Tyrosine
• Ziprasidone

Using this medicine with any of the following medicines may increase the 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 adjust the dose or frequency of use for one or both of the medicines.

• Ginseng

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or certain types of food due to potential interactions. Using alcohol or tobacco with certain medicines may also cause interactions. The following interactions are selected based on their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following is not recommended. Your doctor may decide not to treat you with this medication, change some of the other medicines you take, or give you special instructions regarding food, alcohol, or tobacco use.

• Ethanol

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 adjust the dose or frequency of use for this medicine, or provide special instructions regarding food, alcohol, or tobacco.

• Avocado
• Bitter Orange
• Tyramine Containing Food

Other Medical Problems

Having other medical problems may affect the use of this medicine. Make sure to inform your doctor if you have any other medical issues, especially:

• Glucose-6-phosphate dehydrogenase deficiency (lack of G6PD enzyme)—Patients with G6PD deficiency may develop mild anemia while taking furazolidone.

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

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

Rare

• Fever
• itching
• joint pain
• skin rash or redness
• sore throat

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, are bothersome, or if you have any questions about them:

Less common

• Abdominal or stomach pain
• diarrhea
• headache
• nausea or vomiting

This medicine commonly causes dark yellow to brown discoloration of urine. This side effect does not usually need medical attention.

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.

Chemical Class: Nitrofuran

Do not give furazolidone to infants up to 1 month of age, unless otherwise directed by your doctor. This medicine may cause anemia in these patients.

Furazolidone may be taken with food to lessen the chance of an upset stomach.

To use the oral suspension:

• 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.

To help clear up your infection completely, keep taking furazolidone for the full time of treatment, even if you begin to feel better after a few days. If you stop taking this medicine too soon, your symptoms may return. Do not miss any doses.

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 (oral suspension or tablets): For cholera or diarrhea caused by bacteria: Adults—100 milligrams (mg) taken four times a day for five to seven days. Children up to 1 month of age—Use is not recommended. Children 1 month of age and over—Dose is based on body weight and must be determined by your doctor. The usual dose is 1.25 mg per kilogram (kg) (0.56 mg per pound) of body weight taken four times a day for five to seven days. For giardiasis: Adults—100 mg taken four times a day for seven to ten days. Children up to 1 month of age—Use is not recommended. Children 1 month of age and over—Dose is based on body weight and must be determined by your doctor. The usual dose is 1.25 mg to 2 mg per kg (0.56 to 0.90 mg per pound) of body weight taken four times a day for seven to ten days.

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.