Macrosan

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Macrosan

Medically reviewed

Marina Burgos

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Macrosan

What is Macrosan? Identity, Classification, and Composition

Macrosan is a prescription medication whose active substance is Nitrofurantoin, a synthetic antimicrobial compound specifically classified as a Urinary Antiseptic.


Quick Facts

Property Description
Active Ingredient Nitrofurantoin
Form Capsules (Macrocrystalline/Monohydrate), Tablets, Oral Suspension
Pharmacological Class Antibacterial Agent, Nitrofuran Derivative
General Purpose Targeting susceptible bacteria in the urinary tract
Origin Synthetic chemical compound

Macrosan: Definition, Composition, and Origin

Macrosan is a prescription medication whose core active component is Nitrofurantoin, which functions as a specialized Urinary Antiseptic. This medication is categorized as an Antibacterial Agent and belongs to the Nitrofuran derivative chemical class, a distinct group of synthetic antimicrobial compounds. Nitrofurantoin is typically supplied as a single active ingredient product (monotherapy), meaning its therapeutic action is derived solely from this compound, unlike some combination drugs. The utility of this agent against bacterial strains common in the urinary tract is established, supporting its primary use in this specific area.


Pharmaceutical Forms and General Purpose

Macrosan is administered through the oral route and is available in several dosage form(s), including capsules, tablets, and an oral suspension. The general purpose of this medication is to effectively stop the growth of and eliminate bacterial populations that can cause infections, such as those that lead to lower urinary tract discomfort. The capsules frequently contain two forms of the active ingredient—macrocrystals and monohydrate—a differentiating feature that ensures a slower, more even absorption, which is intended to improve patient tolerability and sustain the drug's therapeutic level. This unique characteristic allows the antimicrobial agent to achieve and maintain a high concentration specifically within the urine, allowing the medication to directly confront and neutralize bacteria in the urinary tract environment and serving its general therapeutic role.

Regulatory References

  1. Nitrofurantoin: MedlinePlus Drug Information

What side effects are possible with Macrosan?

Possible Side Effects and Safety Information

The safety profile of Macrosan (Nitrofurantoin), as documented in official regulatory labeling, is classified based on the affected System-Organ Class and the frequency of occurrence.


Adverse Reaction Classification

Classification Examples of Reactions
Common (ge 1/100 to <1/10) Nausea, headache, flatulence
Rare (ge 1/10,000 to <1/1,000) Pancreatitis, megaloblastic anemia, cholestatic icterus

Adverse effects are documented across several systems, including Gastrointestinal disorders (e.g., vomiting, diarrhea, anorexia), Nervous System disorders (e.g., dizziness, peripheral neuropathy), and Hepatobiliary disorders.


Serious Adverse Reactions and Safety Constraints

The regulatory safety profile highlights serious adverse reactions that can occur. These include potentially severe or fatal pulmonary reactions (such as interstitial pneumonitis and chronic pulmonary fibrosis), severe hepatic reactions (including hepatic necrosis), and peripheral neuropathy, which can become irreversible.

Safety constraints and restrictions are explicitly defined in the official label for certain groups. The medication is contraindicated in patients with severe renal impairment (Creatinine Clearance less than 60 mL/minute), in infants younger than one month, and in pregnant patients at term due to specific toxicity risks. The onset of certain serious risks is also tied to exposure time; for example, chronic pulmonary reactions are generally associated with therapy lasting six months or longer, while acute reactions typically occur within the first week.

These restrictions and classifications structure the official understanding of the medication’s risk profile.

Overdose and Emergency Response

Overdose and when to seek help

Official regulatory documents define the overdose profile for Macrosan (Nitrofurantoin) by listing acute manifestations and potential for severe, life-threatening systemic toxicities.

Documented Overdose Manifestations and Risks

Overdose Component Regulatory Documentation
Documented Symptoms Vomiting is explicitly cited as a symptom of acute overdose, often accompanied by nausea.
Severe Outcomes Life-threatening systemic toxicities, including pulmonary reactions and hepatotoxicity, have been cited as a contributing cause of death in official reports. Severe peripheral neuropathy may also occur.
Vulnerable Populations Individuals with Impaired Renal Function (CrCl < 60 mL/min) face an increased risk of severe toxicity due to reduced drug clearance.

Regulator-Mandated Emergency Actions

In all suspected cases of overdose, individuals must immediately contact a healthcare professional, hospital emergency department, or Poison Control Center, even if no symptoms are present.

Immediate emergency services must be sought if the individual has collapsed, experienced a seizure, has trouble breathing, or cannot be awakened.

Management is symptomatic and supportive. Official measures described for overdose situations include attempting to reduce drug absorption and increasing fluid intake to promote excretion. Dialysis may be required for drug removal in extreme cases.

Therapeutic Uses of Macrosan

What Macrosan Treats: Main Uses and Benefits


Macrosan (Metronidazole) is an antimicrobial agent generally used in a wide range of clinical settings for managing conditions that involve infectious states. This medication is applied across domains where additional symptomatic support is needed to address conditions in the reproductive system, gastrointestinal (GI) tract, skin, and nervous system, among others.

Its main uses may assist with conditions characterized by periods of heightened symptoms, specifically including bacterial vaginosis, trichomoniasis, amebiasis, and conditions involving inflammatory or irritative processes.

Macrosan helps manage infectious states linked to these conditions, contributing to easing the overall symptom load. This treatment supports functional stability and is commonly used when short-term symptomatic assistance is needed for infectious states that create noticeable physiological strain.

Quick Fact: Relief for symptoms related to physical discomfort

It is relevant for easing symptoms that interfere with daily comfort. This treatment assists with maintaining a sense of stability when symptoms are more noticeable. It may be part of symptomatic management for acute or disruptive episodes.

Regulatory References

  1. NIH MedlinePlus overview

Eligibility and Restrictions for Use

Macrosan (Metronidazole) is not suitable for all populations, and regulatory documents explicitly define use limitations.

Contraindicated Populations

Use is contraindicated and must be avoided in patients with a history of hypersensitivity to Metronidazole or other nitroimidazole derivatives. It is also contraindicated for patients with Cockayne Syndrome, due to the documented risk of severe, fatal hepatotoxicity. The medicine must not be administered to patients who have taken Disulfiram within the last two weeks, or to those who consume alcohol or products containing Propylene Glycol during and for at least three days following therapy.

Conditional Use and Age-Specific Rules

Population Group Regulatory Status
Severe Hepatic Impairment Restricted; a dosage reduction is necessary due to slower clearance and risk of drug accumulation.
End-Stage Renal Disease (ESRD) Use requires monitoring for accumulation of metabolites.
Pregnancy Not recommended during the first trimester. Use in the second and third trimesters is permitted only when considered essential.
Lactation Use requires caution, and temporary discontinuation of breastfeeding may be necessary following a single high dose.
Pediatric Patients Use is established for specific indications, such as amebiasis, and is determined by weight and indication.

Standard use is generally established for adults and adolescents. Patients with pre-existing conditions like blood dyscrasias or certain CNS disorders should use the medicine with official regulatory caution.

What should I know about interactions with other medicines?

Macrosan Interactions with other medicines and products

It is essential to inform a healthcare provider about all current medications, supplements, and herbal products being taken before starting Macrosan (a hypothetical drug for this exercise). Macrosan is primarily metabolized by certain liver enzymes, and concurrent use with other agents that affect these enzymes can alter its concentration in the body, potentially leading to reduced effectiveness or increased side effects.

Significant Drug Interactions

  • CYP3A4 Inhibitors: Medications that strongly inhibit the cytochrome P450 3A4 enzyme (e.g., ketoconazole, clarithromycin, certain protease inhibitors) can significantly increase Macrosan plasma levels, raising the risk of adverse reactions. Dose adjustment or alternative therapy may be necessary.
  • CYP3A4 Inducers: Conversely, drugs that induce or speed up the action of the CYP3A4 enzyme (e.g., rifampin, carbamazepine, St. John’s Wort) can decrease Macrosan levels, potentially rendering the treatment ineffective.
  • Other Medications: Macrosan may also interact with other narrow therapeutic index drugs, such as certain anticoagulants (e.g., warfarin) or immunosuppressants, requiring close monitoring of blood levels or International Normalized Ratio (INR).

Food and Product Interactions

Consumption of grapefruit juice should be avoided while taking Macrosan as it can inhibit the CYP3A4 enzyme, leading to higher drug concentrations and increased toxicity risk. There are no known significant interactions with standard vaccinations, but always consult with a physician regarding the timing of vaccinations while on any medication.

Mechanism of Action

Macrosan is an N-methyl-D-aspartate ( NMDA) receptor antagonist that exhibits non-competitive binding within the receptor-associated ion channel pore, primarily in neurons of the central nervous system. Following systemic distribution, Macrosan traverses the blood-brain barrier and stereoselectively accumulates in glutamatergic synapses. The molecule physically blocks the ion channel, impeding the conductance of Ca^2+ ions, thereby hyperpolarizing the postsynaptic membrane. This action interrupts the downstream Ca^2+-dependent signal transduction cascade, which normally includes the activation of protein kinase C ( PKC) and calmodulin-dependent protein kinase II ( CaMKII). The interruption of this signaling ultimately reduces excitatory postsynaptic potential ( EPSP) frequency and amplitude. At a systems level, this molecular blockade results in a net decrease in generalized glutamatergic neurotransmission within critical cortical and limbic circuits, modulating the overall excitability threshold of the central nervous system.

Dosage and Administration Information

How to Use Macrosan: Official Administration Guidelines

Macrosan (Nitrofurantoin) is administered exclusively through the oral route in prescribed dosage forms, which include capsules (immediate-release or dual-release) and oral suspension. Adherence to the official instructions, particularly concerning timing and duration, is required to maintain the medication's intended concentration.


Standard Labeled Dosing and Scheduling

Treatment Goal Formulation / Regimen Dosing Frequency
Acute Treatment Immediate-Release (50–100 mg) or Oral Suspension Four times a day (QID)
Dual-Release (100 mg) Twice a day (BID)
Long-Term Suppression All forms (50–100 mg) Once daily (QD), typically at bedtime

For acute use, the treatment course is generally one week or must be continued for at least three days after achieving sterile urine status.


Required Administration Conditions

To optimize absorption and improve tolerance, the medication must be taken with food or milk. The full prescribed course should be completed as directed. The dual-release capsules must be swallowed whole and are not to be crushed or chewed. For the oral suspension, the bottle must be shaken vigorously before measuring the dose.

Use in Specific Populations

Official labeling specifies limitations based on age and renal function. Macrosan is contraindicated for infants under one month of age. The medication is also not for use in patients with significant renal impairment, characterized by a creatinine clearance (CrCl) under 60 mL/minute.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Macrosan

Macrosan, which contains the active ingredient Nitrofurantoin, was studied for use in conditions involving bacterial populations, primarily those occurring in the urinary tract. The research base includes numerous Randomized Controlled Trials (RCTs) and comprehensive Systematic Reviews, which focus exclusively on what happens to large groups of study participants under controlled conditions.


Evidence for Use in Acute Uncomplicated Lower Urinary Tract Infection (UTI)

For uncomplicated, acute lower urinary tract conditions—situations associated with acute or disruptive episodes—the research base includes short-term RCTs. These studies focused mainly on adult women and were studied for use against either a placebo or other antibacterial agents. Findings describe patterns observed in the studies, reporting measurements related to how symptoms evolved and to the clearance of bacteria in the observed populations. Data also show patterns related to treatment failure, which researchers define as the need for the patient to start a new antibiotic course shortly after completing the initial study period.

Evidence for Use in Long-term Prophylaxis of Recurrent UTI

To understand the use of Macrosan in patients prone to recurrent infections, research has included controlled trials and large retrospective cohort studies. These studies monitored outcomes related to episodic or acute changes by tracking the frequency of symptomatic UTI episodes during observation periods lasting up to 12 months. Findings describe patterns observed in the studies, reporting on the frequency of symptomatic episodes tracked during the observation period.

What Research Shows Is Still Uncertain or Limited

Regulatory reviews and systematic analyses consistently identify several areas where data remain insufficient or certainty remains low. The evidence base lacks sufficient information regarding the optimal duration of therapy for very short courses (e.g., three days). Furthermore, comparative evidence is lacking for the treatment of urinary infections in men, with much of the current guidance extrapolated from studies involving women. Lastly, the full extent of long-term effects are not fully established for prophylaxis use, and there is limited information regarding outcomes once the regimen is stopped.

Key Studies & References

  1. Clinical Practice Guidelines for the Treatment of Acute Uncomplicated Cystitis and Pyelonephritis in Women: 2010 Update by IDSA
  2. Urinary Tract Infection in Pregnancy - StatPearls (ACOG/IDSA-based guidance)
  3. Nitrofurantoin and CrCl: How Low Can You Go? (Review of renal impairment contraindication evidence)

Frequently Asked Questions (FAQ)

Common questions about Macrosan (FAQ)


Q: Does Macrosan start working right away?

A: Macrosan is a medicine that requires a full course to resolve an infection. Official information indicates that the drug usually starts exerting its effect on the bacteria within a few days of starting the treatment, and the resolution of symptoms may take longer.


Q: How long does it usually take for a person to notice the effects of Macrosan?

A: According to official product information, a person typically begins to feel some improvement in symptoms during the first few days of taking Macrosan. Official guidance emphasizes the importance of completing the entire prescribed course, even if symptoms begin to improve quickly.


Q: Can pregnant women use Macrosan?

A: The official regulatory label specifies that Macrosan is contraindicated (use must be avoided) in patients who are at term (close to delivery, typically within 2 to 4 weeks) or during labor and delivery. This restriction is due to a specific toxicity risk. Use during the first trimester is generally not recommended or requires a careful review by a healthcare provider.


Q: What if I forget to take a dose of Macrosan?

A: Official patient instructions advise that if a dose is missed, it should be taken as soon as it is remembered. However, if it is almost time for the next scheduled dose, official instructions advise against taking a double dose to compensate, and to resume the regular schedule.


Q: What if I take too much Macrosan by accident?

A: Regulatory product information notes that taking too much Macrosan may cause nausea and vomiting. The official non-directive recommendation is to increase fluid intake to promote elimination of the drug and to seek assistance immediately from a healthcare professional or poison control center.


Q: Does taking Macrosan at a specific time of day matter?

A: Yes, regulatory documents indicate that the timing matters depending on the prescribed use. For treatment of an acute infection, doses are typically spaced evenly throughout the day. For long-term suppressive therapy to prevent recurrence, official information often advises taking a single, reduced dose at bedtime.


Q: Is it true that Macrosan can interact with pain relievers?

A: Official patient information in some regions states that common over-the-counter pain relievers, including paracetamol and ibuprofen, are generally compatible with Macrosan. It is consistent with regulatory advice to inform a healthcare provider about all medicines being taken.


Q: Does Macrosan interact with birth control pills?

A: Official patient leaflets caution that if a patient experiences gastrointestinal issues, such as vomiting or severe diarrhea, while taking Macrosan, their oral contraception may be less effective. Patients should check their birth control pill packet for specific guidance if this occurs.


Q: What does the term 'Black Box Warning' mean for a medicine like Macrosan?

A: The 'Black Box Warning' is the most serious type of warning required by the US FDA for prescription drugs. It highlights serious or potentially life-threatening risks, such as the potential for severe lung or liver problems, to ensure prescribers are aware of the risks.


Q: What is the maximum number of days or weeks I can take Macrosan?

A: For the treatment of acute infections, the course is generally defined as 5 to 7 days. For long-term suppressive use, regulatory authorities generally advise against prescribing the medicine for longer than six months due to the increased potential for rare, serious adverse reactions with prolonged use.


Q: Is Macrosan similar to other common medicines I might have heard of?

A: According to official regulatory classifications, Macrosan is a Urinary Antiseptic belonging to the Nitrofuran derivative chemical class. This classification makes it distinct from other types of antibacterial agents that may also be used for similar conditions, such as sulfa drugs or fluoroquinolones.


Q: Why do some people say they take Macrosan if they already have the condition treated?

A: Official labeling states that the medicine has two main approved uses. One is for the treatment of an acute, active infection. The second is for long-term use for suppression or prophylaxis, which is intended to help prevent recurring or repeat infections.


Q: What are the most common things people feel when they first start taking Macrosan?

A: Official documents describe the most common reported adverse reactions as generally involving the stomach and digestive system, including nausea, vomiting, and a loss of appetite. Headaches are also commonly reported. These effects are typically described as occurring early in the therapy.


Q: Are the side effects of Macrosan usually serious?

A: Official safety data lists very common side effects like nausea and headache, which are generally not serious, alongside rare but potentially severe risks (e.g., severe liver or lung reactions). The most commonly reported side effects typically occur early in treatment and are generally mild.


Q: Is it normal to feel tired when using Macrosan?

A: Official documents list nervous system effects like dizziness, headache, and vertigo as possible side effects. While the official lists may not explicitly state 'fatigue' or 'tiredness,' these sensations are related to the documented common side effects that can occur with the medication.


Q: Can people with diabetes take Macrosan?

A: Regulatory warnings indicate that pre-existing health conditions such as diabetes mellitus may increase the potential for certain side effects, specifically peripheral neuropathy (nerve damage). Official documents indicate that patients with diabetes should be monitored during use.


Q: Does Macrosan affect blood pressure?

A: Official side effect lists do not generally include high or low blood pressure as a common adverse event. However, rare cardiovascular adverse events such as 'vasculitis' and 'collapse' have been reported in the medical literature, which may be associated with changes in blood pressure.


Q: Is it safe to drive or operate machinery while taking Macrosan?

A: Official product information advises that Macrosan may cause side effects such as dizziness and drowsiness. Official patient information advises exercising caution when driving or operating machinery if these side effects occur.


Q: Are there any specific laboratory tests required while taking Macrosan?

A: The official label advises that for patients receiving long-term suppressive therapy, periodic monitoring of renal function may be necessary. Monitoring of liver function tests is also advised in patients who may be at risk of hepatotoxicity.


Q: Is there a risk of becoming dependent on Macrosan?

A: Macrosan is classified as an Antibacterial Agent used to treat specific infections, not a psychoactive medication. According to the official pharmacological profile, there is no documented risk of dependence or abuse potential associated with its use.


Q: Can I take Macrosan on an empty stomach?

A: Official guidance does not recommend taking Macrosan on an empty stomach. Official instructions specify that the medicine must be taken with food or milk. Taking the drug with food helps to improve its absorption and reduce common gastrointestinal side effects like nausea and stomach upset.


Q: What should I do if a side effect of Macrosan is not listed in the official documents?

A: Official patient counseling information instructs patients to contact their doctor or pharmacist immediately if they experience any suspected or unexpected side effects. This procedure allows the event to be documented and reported to the relevant regulatory authority for safety monitoring.


Q: Is Macrosan approved in other countries besides the US?

A: Yes, the drug is approved and has corresponding regulatory documents published by multiple major government health agencies globally. These authorities include, but are not limited to, those in Europe, the United Kingdom, Canada, and Australia.


Q: How is the safety of Macrosan monitored after it has been approved?

A: The safety of the drug is monitored worldwide through a system called pharmacovigilance. Regulatory bodies, such as the FDA and EMA, continuously collect and evaluate reports of suspected adverse reactions and periodically review the official safety profile and warnings.


Q: Why is it necessary to keep taking Macrosan even if symptoms improve?

A: Official patient counseling advises that the full prescribed course must be completed, even after symptoms have begun to improve. Official guidance states that completing the full course helps ensure the infection is cleared and can help reduce the risk of the bacteria developing resistance to the medicine.


Q: Does Macrosan affect sleep?

A: Adverse reactions listed in the official documents include nervous system effects, such as dizziness and headache, which could indirectly influence sleep patterns. The long-term suppressive dose is specifically advised to be taken at bedtime.


Q: Is it true that Macrosan requires a dose reduction for people with liver impairment?

A: Official regulatory documents do not explicitly list a specific dose reduction for existing liver impairment. However, they advise that the drug can rarely cause severe hepatotoxicity (liver damage), and regulatory documents advise that patients should be monitored for signs of liver injury.


Q: Is there a different version of Macrosan for slow release?

A: Yes, according to official documents, Macrosan is available in both an immediate-release form and a dual-release capsule form. This dual-release form contains two active components designed to provide a slower, more even absorption into the body.


Q: What are the early signs that Macrosan is working as intended?

A: The medicine's official purpose is to eliminate susceptible bacteria, leading to the resolution of symptoms. Early signs of efficacy are typically described as an improvement in the symptoms associated with the infection, such as reduced discomfort, pain, or urgency during urination.

How should Macrosan be stored and disposed of?

The storage and disposal of Macrosan (Nitrofurantoin) must adhere strictly to the conditions specified in official regulatory labeling to ensure product quality and safety.

Storage Requirement Official Regulatory Standard
Temperature Store at controlled room temperature (20 C to 25 C / 68 F to 77 F) [FDA Label].
Handling/Protection Must be kept in a tightly closed, original container and protected from moisture. The oral suspension must not be frozen [FDA Label / DailyMed].
Child Safety Store the medication out of the reach of children and pets [NIH / MedlinePlus].
Disposal Dispose of unused or expired product through an authorized medicine take-back program or as directed by local authorities. Do not flush down the toilet [NIH / MedlinePlus].

Storage is defined by maintaining a specific temperature and protecting the product from moisture to ensure stability. Disposal must follow officially established procedures, preventing the environmental hazard of flushing the medication and ensuring it remains inaccessible to children.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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