Search. Learn. Save

Platform for Pharmaceutical Products for Healthcare Professionals
Search By
☰ Generic Formulas

Generic Formulas X

Furazolidone Oral

Furazolidone, Oral: An In-Depth Review of Its Uses, Mechanism, and Benefits

Introduction

Furazolidone is an antimicrobial medication used to treat various bacterial and protozoal infections. It belongs to a class of drugs known as nitrofurans, which are similar to nitroimidazoles in their ability to interfere with bacterial DNA and protein synthesis. Furazolidone is especially effective against gastrointestinal infections and is typically administered in oral form. While furazolidone has been largely replaced by other more commonly prescribed antibiotics in many parts of the world, it remains an important option in specific clinical scenarios, particularly for treating infections caused by protozoa and Gram-positive bacteria.

1. Furazolidone

Furazolidone is a synthetic nitrofuran derivative used as an antimicrobial agent. It is primarily effective against a range of bacterial and protozoal infections, particularly those affecting the gastrointestinal system. Furazolidone was first introduced in the 1960s and has since been used to treat a variety of infections, particularly in developing countries where diseases like giardiasis, dysentery, and diarrheal infections are more prevalent.

Furazolidone is typically administered orally in tablet form and works by inhibiting microbial enzymes, leading to the death of the pathogen.

2. Mechanism of Action

The mechanism of action of furazolidone is related to its nitrofuran structure, which enables it to interfere with vital microbial processes.

1. Disruption of DNA Synthesis

Furazolidone acts by disrupting bacterial DNA. The drug is metabolized inside the bacterial cell to its active form, which then reacts with the DNA of the bacteria, leading to strand breaks. This inhibition of DNA synthesis prevents the bacteria from replicating and eventually causes cell death.

2. Inhibition of Bacterial Enzymes

Furazolidone also inhibits the activity of oxidative enzymes within the microorganism. Specifically, it targets enzymes involved in aerobic respiration, reducing the bacteria's ability to generate energy. This energy depletion further weakens the bacteria, leading to its inability to sustain vital functions.

3. Antiprotozoal Activity

Furazolidone is also active against protozoa such as Giardia lamblia, which causes giardiasis, and Entamoeba histolytica, which is responsible for amoebic dysentery. Its antiprotozoal action occurs through similar mechanisms, involving disruption of protozoal cellular processes and DNA damage.

3. Clinical Uses of Furazolidone

Furazolidone has several important clinical applications, most of which are related to its ability to treat infections of the gastrointestinal tract, caused by bacteria or protozoa.

1. Diarrheal Infections

Furazolidone is often prescribed to treat diarrhea, particularly in cases caused by infectious agents. It is particularly effective in treating infections due to Giardia lamblia, Entamoeba histolytica, and certain Gram-negative and Gram-positive bacteria.

In some regions, furazolidone is considered a first-line treatment for traveler’s diarrhea, a condition commonly caused by enteric pathogens encountered during travel to developing countries. Its broad-spectrum antimicrobial properties make it effective against a variety of organisms that cause diarrheal illness.

2. Giardiasis

Giardiasis is a protozoal infection caused by Giardia lamblia. This infection can cause symptoms such as diarrhea, stomach cramps, bloating, and nausea. Furazolidone is used to treat giardiasis, particularly in regions where this parasitic infection is endemic. By targeting Giardia lamblia’s DNA and metabolic pathways, furazolidone helps eradicate the parasite from the intestines.

3. Amoebiasis

Furazolidone is also effective in treating amoebiasis, an infection caused by the protozoan Entamoeba histolytica. Amoebiasis can result in dysentery, characterized by bloody diarrhea, abdominal pain, and sometimes fever. Furazolidone can help eliminate the parasite, reduce symptoms, and prevent complications such as liver abscesses.

4. Bacillary Dysentery

Bacillary dysentery is a bacterial infection often caused by Shigella species. It results in severe diarrhea, often with blood and mucus in the stool, along with fever and abdominal cramping. Furazolidone’s broad-spectrum activity against both Gram-positive and Gram-negative bacteria makes it an effective treatment for dysentery, particularly in developing countries.

5. Other Uses

Furazolidone has been explored for use in other infections, including helminthic infections, though it is not the first-line therapy in these cases. Due to its broad antimicrobial properties, it can sometimes be used when other treatments are unavailable.

4. Dosage and Administration

Furazolidone is typically administered orally in the form of tablets. The exact dosage depends on the type and severity of the infection, as well as the patient’s age and medical condition.

1. Giardiasis

For giardiasis, the typical adult dosage of furazolidone is 100 mg every 6 hours for 7-10 days. Pediatric dosages are adjusted based on weight.

2. Amoebiasis

For amoebiasis, the adult dose of furazolidone is generally 100 mg every 6 hours for 7 days.

3. Diarrheal Infections

For diarrheal infections, the dosage is typically 100 mg every 6 hours for 5-7 days, depending on the severity of the infection.

4. Dosage Adjustments

The dosage of furazolidone may need to be adjusted in patients with liver disease or renal impairment, as the drug is metabolized by the liver and excreted by the kidneys. Liver function tests should be monitored periodically.

5. Side Effects of Furazolidone

Like all medications, furazolidone can cause side effects, although not everyone will experience them. Most side effects are mild and temporary, but some can be more serious.

Common Side Effects

  • Nausea and vomiting

  • Abdominal pain or discomfort

  • Loss of appetite

  • Headache

  • Fatigue or dizziness

  • Dark urine (a common but harmless side effect related to the drug’s metabolite)

Serious Side Effects

  • Hemolytic anemia (especially in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency)

  • Liver toxicity: Elevated liver enzymes can occur, which may indicate liver damage.

  • Peripheral neuropathy: Prolonged use can occasionally result in nerve damage, leading to symptoms like tingling or numbness.

  • Allergic reactions: Rash, itching, or more severe reactions like angioedema (swelling of the face, lips, or throat).

Patients should immediately seek medical attention if they experience any of the following:

  • Severe allergic reactions (difficulty breathing, swelling of the face or throat)

  • Yellowing of the skin or eyes (a sign of liver dysfunction)

  • Unusual fatigue or weakness

6. Precautions and Contraindications

1. Pregnancy and Breastfeeding

Furazolidone is classified as a category C drug by the FDA for use during pregnancy, meaning its safety during pregnancy has not been fully established. Pregnant women should avoid using furazolidone unless absolutely necessary and prescribed by a healthcare provider.

Furazolidone is excreted in breast milk, so it is advised to avoid the use of furazolidone while breastfeeding or to discontinue breastfeeding if treatment is required.

2. G6PD Deficiency

Individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency should avoid furazolidone due to the risk of hemolytic anemia. This condition can cause the destruction of red blood cells, leading to symptoms like fatigue, paleness, and dark urine.

3. Liver and Kidney Impairment

Furazolidone should be used with caution in individuals with liver disease or renal impairment, as these conditions may affect the metabolism and excretion of the drug. Liver function tests should be monitored periodically during treatment.

7. Drug Interactions

Furazolidone can interact with a number of drugs, which may lead to enhanced side effects or reduced efficacy.

1. Alcohol

Furazolidone should not be taken with alcohol, as this combination may cause a disulfiram-like reaction, leading to symptoms like nausea, vomiting, and flushing.

2. Monoamine Oxidase Inhibitors (MAOIs)

Furazolidone should not be taken with MAO inhibitors (e.g., phenelzine), as the combination can lead to hypertensive crisis—a dangerous increase in blood pressure.

3. Other Antibiotics

Concurrent use with other antibiotics, especially aminoglycosides or penicillins, may result in altered efficacy of the medications.

8. Conclusion

Furazolidone is an important antimicrobial medication, particularly for the treatment of gastrointestinal infections caused by protozoa and bacteria. Its broad-spectrum activity makes it effective in treating conditions like giardiasis, amoebiasis, and dysentery. Despite its usefulness, it must be used cautiously due to potential side effects and interactions with other drugs. Patients prescribed furazolidone should follow their healthcare provider's recommendations carefully, monitor for side effects, and attend regular follow-up appointments to ensure the safe and effective use of the drug.