Fosfomycin Antibiotic: Uses, Dosage, and UTI Treatment

Summary of Key Points

Fosfomycin is a broad-spectrum antibiotic commonly used to treat bacterial infections, particularly those affecting the urinary tract. It works by preventing the growth of bacteria. Fosfomycin is often prescribed for uncomplicated urinary tract infections (UTIs) and cystitis. It is available in powder form, which must be mixed with water before taking. Always consult your healthcare provider before starting or adjusting your dose. Our telemedicine providers are available to answer any questions you may have about Fosfomycin, including its uses and dosage.

Names of Medication

US Brand Name: Monurol (Fosfomycin)

The generic name refers to the active ingredient, while the brand name is assigned by the manufacturer. In this case, Fosfomycin is the generic name, and Monurol is the brand name.

Pharmacologic Category

Antibiotic, Phosphonic Acid Derivative

Fosfomycin Dosage

Fosfomycin is used to treat a variety of bacterial infections. Below are the recommended doses for adults. Always consult your healthcare provider before making any changes to your dosage. If you need assistance, our telemedicine providers are here to help.

1. Uncomplicated Urinary Tract Infection (UTI) / Cystitis: 3 grams (one sachet) taken as a single dose, mixed with water. This is typically a one-time treatment.
2. Pyelonephritis (Kidney Infection): Fosfomycin is not usually the first choice for treating pyelonephritis. Consult your healthcare provider for the most appropriate treatment options.
3. Bacterial Prostatitis: 3 grams every 48 hours for 3 doses. The duration of treatment may vary depending on the severity of the infection. Always follow your healthcare provider’s instructions.
4. Osteomyelitis (Bone Infection): Dosing for osteomyelitis is individualized. Consult your healthcare provider for the appropriate dosage and treatment duration.
5. Skin and Soft Tissue Infections: Fosfomycin is not commonly used for these types of infections. Your healthcare provider will determine the best treatment plan for you.
6. Respiratory Tract Infections: Fosfomycin is not typically prescribed for respiratory infections. Consult your healthcare provider for alternative treatments.
7. Endocarditis (Heart Infection): Fosfomycin may be used in combination with other antibiotics. Dosing is individualized based on the specific infection. Consult your healthcare provider for guidance.
8. Bone Infections: Dosing is individualized. Consult your healthcare provider for the appropriate treatment plan.
9. Intra-abdominal Infections: Fosfomycin is not typically used for these infections. Your healthcare provider will recommend the most suitable treatment.

Dosage Forms and Strengths

Oral powder for solution: 3 grams per sachet

Administration Instructions

Fosfomycin comes as a powder that must be mixed with water before taking. To prepare, empty one sachet into a glass of water (about 3 to 4 ounces), stir well, and drink immediately. Do not take the medication in its dry form. It can be taken with or without food. Follow your healthcare provider’s instructions carefully, and do not skip doses. If you have any questions about how to take Fosfomycin, our telemedicine providers are available to assist you.

Fosfomycin Side Effects

Like all medications, Fosfomycin can cause side effects. Most are mild, but some may be more serious. If you experience any side effects, contact your healthcare provider immediately. Below is a list of potential side effects:

Common Side Effects (1-10%)

1. Diarrhea: Loose stools are a common side effect. Staying hydrated is important.
2. Nausea: Some patients may feel nauseous after taking Fosfomycin.
3. Headache: Mild headaches may occur but usually resolve on their own.

Less Common Side Effects (<1%)

1. Vaginitis: Inflammation or infection of the vagina may occur in some women.
2. Abdominal pain: Some patients may experience stomach discomfort.

Serious Side Effects (Rare)

1. Allergic reactions: Symptoms may include rash, itching, swelling, or difficulty breathing. Seek medical attention immediately if these occur.
2. Severe diarrhea (Clostridium difficile-associated diarrhea): This is a rare but serious side effect that requires immediate medical attention.

Contraindications

A contraindication is a specific condition or situation where a medication should not be used because it may cause harm. If you have any of the following conditions, taking Fosfomycin may not be safe. Always consult your healthcare provider before starting any new medication, and if you have any of these conditions, be sure to discuss them with one of our telemedicine providers.

1. Severe kidney disease (renal impairment): Fosfomycin is primarily eliminated through the kidneys. If your kidneys are not functioning properly, the medication may not be cleared effectively, leading to potential toxicity.
2. Allergy to Fosfomycin: If you have a known allergy to Fosfomycin or any of its components, taking this medication could cause a severe allergic reaction, which can be life-threatening.
3. Dialysis patients: Fosfomycin is not recommended for patients undergoing dialysis, as the drug may not be effectively removed from the body, increasing the risk of side effects.

Drug-to-Drug Interactions

Fosfomycin can interact with other medications, potentially altering its effectiveness or increasing the risk of side effects. Be sure to inform your healthcare provider about all the medications you are taking, including over-the-counter drugs and supplements. Below are some medications that may interact with Fosfomycin:

1. Metoclopramide (Reglan): This medication, used to treat nausea and vomiting, can reduce the absorption of Fosfomycin, making it less effective.
2. Warfarin (Coumadin): Fosfomycin may increase the effects of warfarin, a blood thinner, raising the risk of bleeding.
3. Digoxin (Lanoxin): Fosfomycin may alter the absorption of digoxin, a medication used to treat heart conditions, potentially affecting its efficacy.
4. Antibiotics: Other antibiotics, especially those that affect the kidneys, may increase the risk of kidney-related side effects when taken with Fosfomycin.

Fosfomycin in Pregnancy

Is it safe to take Fosfomycin when pregnant?

Fosfomycin is classified as a Category B drug by the FDA for use during pregnancy. This means that animal studies have not shown harm to the fetus, but there are not enough well-controlled studies in pregnant women. While Fosfomycin is generally considered safe during pregnancy, it should only be used if clearly necessary. If you are pregnant or planning to become pregnant, it’s important to discuss the potential risks and benefits of Fosfomycin with your healthcare provider. Our telemedicine providers are available to help you make an informed decision.

Fosfomycin while Breastfeeding

Is it safe to take Fosfomycin while breastfeeding?

Fosfomycin is excreted in small amounts in breast milk. While it is generally considered safe for breastfeeding mothers, caution is still advised. If you are breastfeeding, it’s essential to discuss the possible risks and benefits with your healthcare provider. In some cases, your provider may recommend monitoring your baby for potential side effects, such as diarrhea or diaper rash. If you have any concerns, our telemedicine providers are available to guide you through your options.

Estimated Cost of Fosfomycin

The cost of a single-dose packet of Fosfomycin (commonly used to treat urinary tract infections) can vary depending on your location and pharmacy. Without insurance, the estimated cost using a GoodRx coupon ranges from $40 to $70 for a single dose. Prices may fluctuate, so it’s a good idea to check with your pharmacy for the most accurate pricing.

Possible Alternatives to Fosfomycin

Depending on the condition being treated, alternative medications or lifestyle changes may help manage your symptoms. Always consult your healthcare provider before making any changes to your treatment plan. Our telemedicine providers are available to discuss these options with you.

Urinary Tract Infection (UTI)

Alternatives include nitrofurantoin (Macrobid), trimethoprim-sulfamethoxazole (Bactrim), or lifestyle adjustments such as increasing water intake and urinating frequently to help flush out bacteria.

Cystitis

Other antibiotics, such as ciprofloxacin (Cipro) or amoxicillin-clavulanate (Augmentin), may be prescribed. Additionally, drinking cranberry juice or taking cranberry supplements may help prevent recurrent infections.

Pyelonephritis

Severe kidney infections may require intravenous antibiotics like ceftriaxone (Rocephin) or levofloxacin (Levaquin). In more serious cases, hospitalization may be necessary.

Bacterial Prostatitis

Alternatives include fluoroquinolones such as ciprofloxacin (Cipro) or levofloxacin (Levaquin). Warm baths and anti-inflammatory medications may also help alleviate symptoms.

Osteomyelitis

Treatment often involves long-term antibiotics like vancomycin or cefazolin. In severe cases, surgery may be required to remove infected tissue.

Skin and Soft Tissue Infections

Alternatives include clindamycin (Cleocin) or doxycycline. Keeping the affected area clean and dry can also promote healing.

Respiratory Tract Infections

Depending on the bacteria involved, alternatives may include azithromycin (Zithromax) or amoxicillin. Using a humidifier and staying hydrated can help ease symptoms.

Endocarditis

This serious infection often requires intravenous antibiotics like penicillin or vancomycin. In some cases, surgery may be needed to repair damaged heart valves.

Bone Infections

Long-term antibiotics such as clindamycin or cephalexin (Keflex) are commonly used. In severe cases, surgery may be necessary to remove infected bone tissue.

Intra-Abdominal Infections

Treatment may involve antibiotics like metronidazole (Flagyl) or piperacillin-tazobactam (Zosyn). In some cases, surgery may be required to drain abscesses or remove infected tissue.

Recent Updates on Fosfomycin Research

Recent studies suggest that Fosfomycin may be effective against a broader range of bacterial infections, including some multi-drug resistant strains. Ongoing research is exploring the use of Fosfomycin in combination with other antibiotics to treat severe infections, such as those caused by carbapenem-resistant Enterobacteriaceae (CRE). While these findings are promising, more clinical trials are needed to confirm the results. If you’re interested in learning more about new treatment options, our telemedicine providers are available to discuss the latest research and how it may apply to your condition.

James Kingsley

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