Stromac

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Medically reviewed

Marina Burgos

Last updated on 10/01/2026

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 Stromac

Quick Facts

Property Description
Active Ingredient Azithromycin
Form Tablet, Oral Suspension, IV Solution
Pharmacological Class Macrolide Antibiotic (Azalide Subclass)
Common Use Scenario Treating respiratory or skin bacterial infections
Origin Semisynthetic

What is Stromac? Identity and Classification

Stromac is a pharmaceutical product containing the active substance Azithromycin (INN), a systemic antimicrobial agent used to control the proliferation of susceptible bacteria. This compound is classified as a macrolide antibiotic, belonging specifically to the azalide subclass.

Azithromycin is a semisynthetic compound, chemically derived from erythromycin but modified to improve stability and enhance tissue absorption. This unique structural differentiation is clinically recognized for giving Azithromycin distinct pharmacokinetic properties, such as a long half-life and high concentration in tissues. The core function of the drug is that of a protein synthesis inhibitor: it works by binding to the bacterial ribosome, which blocks the bacteria's ability to produce the essential proteins required for their growth and survival.

Form, Delivery Type, and General Purpose

The medication is supplied as a single-active-ingredient product across several standard dosage forms, including the film-coated tablet and a powder for oral suspension. The suspension form, designed for oral administration, is particularly relevant for pediatric use or for patients who have difficulty swallowing tablets.

Azithromycin's overall general therapeutic purpose is to function as a systemic agent that addresses bacterial infections in various parts of the body, such as the respiratory tract or skin, offering a concise treatment regimen. The medication is intended to treat infections caused by microorganisms susceptible to Azithromycin. By inhibiting the reproductive capacity of susceptible microbes, the drug reduces the organism load, thereby allowing the body's immune system to overcome the infection.

Regulatory References

  1. NIH StatPearls: Azithromycin Pharmacokinetics
  2. European Medicines Agency (EMA)

What side effects are possible with Stromac?

Possible Side Effects and Safety Information

This information details the officially documented safety profile of Stromac, strictly based on regulatory documents from government authorities (e.g., FDA, EMA, Health Canada). The medicine's risk profile is structured by categorizing known adverse reactions, defining serious risks, and noting specific restrictions for use.

Adverse Reaction Scope

Adverse reactions are classified by the affected body system (System-Organ Class) and reported frequency:

  • System-Organ Classes Involved: Reactions are officially documented across several major body systems, including Gastrointestinal, Cardiovascular, Central Nervous System, Hepatobiliary, and Blood and Lymphatic systems.
  • Frequency Classification: Regulatory labels report reactions using standard terms. Examples include: Rare (e.g., reports of somnolence, vertigo, thrombocytopenia, and malaise), with other events noted as Frequency not known when data is insufficient for estimation.

Serious and Clinically Significant Adverse Reactions

Regulatory documents highlight severe adverse events that may be life-threatening or require immediate discontinuation of the medicine:

  • Serious Risks: These include Gastrointestinal Hemorrhage (bleeding), perforation (hole in the wall of the tract), and obstruction (blockage); Arrhythmias (e.g., tachycardia, atrioventricular block); Severe Hepatotoxicity (liver injury) including cholestatic hepatitis and liver failure; and Blood Disorders (e.g., severe thrombocytopenia).
  • Diagnosis Masking: Relief of symptoms does not rule out the presence of a gastric malignancy, as this drug may mask such conditions.

Population-Specific Restrictions

  • Contraindications: The medicine is not to be used in patients with known hypersensitivity (allergy) to the drug or its components. It is also restricted in patients with pre-existing conditions such as active ulcer, gastrointestinal bleeding, perforation, or obstruction.
  • Use Limitations: Caution is officially required in patients with pre-existing kidney or liver impairment. Use in children and very-low-birth-weight neonates has been associated with specific increased risks, leading to official limitations or non-recommendation for use in these populations.
  • Drug-Drug Interactions: Official documents list specific concurrent medications that may increase the risk of adverse reactions, such as other drugs that affect blood clotting or certain metabolism-inhibitors.

Overdose and Emergency Response

An overdose of Stromac, whether accidental or intentional, is a medical emergency that requires immediate professional attention. Taking more than the prescribed dose can lead to severe and potentially life-threatening health complications.

Symptoms of Stromac Overdose

Symptoms can vary depending on the amount taken and the individual's overall health, but may include:

Symptom Category Potential Signs
Central Nervous System Extreme drowsiness, profound confusion, unresponsiveness, or coma.
Cardiopulmonary Slowed or shallow breathing, difficulty breathing, blue or purple discoloration of the lips or fingernails (cyanosis), and a weak or irregular pulse.
Other Physical Signs Cold, clammy skin, constricted (pinpoint) pupils, or limp body muscles.

When to Seek Help

If you suspect that you or someone else has taken too much Stromac, call emergency services immediately. Do not wait for severe symptoms to appear. An overdose is a time-critical situation, and prompt medical treatment is vital for the best outcome. Be prepared to provide the emergency responders with the name of the drug, the estimated amount taken, and the time the overdose occurred. Do not attempt to induce vomiting or give the person food or drink unless instructed by emergency personnel.

Therapeutic Uses of Stromac

Main Uses and Benefits of Stromac

Stromac is a medication primarily indicated for the treatment of specific parasitic infections caused by nematodes (roundworms) and certain ectoparasites. Its active mechanism targets the nervous system of the parasites, leading to their elimination from the host body.

Indications and Targeted Conditions

The medication is most commonly used to manage the following conditions:

  • Strongyloidiasis: An intestinal infection caused by the roundworm Strongyloides stercoralis. The medication helps to clear the parasite from the digestive tract.
  • Onchocerciasis (River Blindness): An infection caused by the bite of infected blackflies carrying the parasite Onchocerca volvulus. Stromac works by killing the immature larvae (microfilariae) in the skin and eyes.
  • Lymphatic Filariasis: A condition caused by microscopic, thread-like worms. Treatment helps reduce the number of microfilariae circulating in the blood.
  • Sarcoptic Scabies: A skin infestation caused by tiny mites that burrow under the skin. It is typically used when topical treatments have proven ineffective or are unsuitable for the patient.

Benefits and Clinical Effects

When used for its indicated purposes, Stromac provides several clinical benefits focused on symptom relief and the prevention of disease progression:

  • Parasitic Clearance: By paralyzing and killing the larvae or adult worms, the medication reduces the overall parasite load in the body.
  • Symptom Management: Successful treatment often leads to the resolution of symptoms associated with these infections, such as skin itching, gastrointestinal distress, and lymphatic swelling.
  • Prevention of Complications: In cases of onchocerciasis, timely treatment is essential to prevent long-term ocular damage and potential blindness. In lymphatic filariasis, it aids in stopping the progression of physical deformities.
  • Community Health Impact: In endemic regions, the use of this medication can help reduce the transmission cycle of specific parasites by lowering the concentration of larvae available to be picked up by insect vectors.

Eligibility and Restrictions for Use

Eligibility Map: Who Can and Cannot Use Stromac — Official Regulatory Information

Category Official Regulatory Statement
Populations for whom use is contraindicated Patients with known hypersensitivity to azithromycin, erythromycin, or any macrolide or ketolide drug [1.1]. Patients with a history of cholestatic jaundice or hepatic dysfunction associated with prior azithromycin use [1.4].
Age-related eligibility rules Safety and effectiveness have not been established for most indications in patients under 6 months of age [1.4, 3.3]. Use in neonates (up to 42 days of life) has been associated with reports of Infantile Hypertrophic Pyloric Stenosis (IHPS) [1.4].
Condition-specific eligibility rules (Restrictions) Caution must be exercised in patients with severe renal impairment (GFR <10 mL/min) and those with significant hepatic disease or severe hepatic impairment [2.2].
Eligibility-related restrictions Use requires caution in patients with known QT prolongation, history of torsades de pointes, or proarrhythmic conditions [1.6]. Stromac may exacerbate muscle weakness in persons with Myasthenia Gravis [1.4].
Populations for whom use is not recommended Oral therapy is not recommended for patients with pneumonia judged to be inappropriate for oral treatment due to severity or risk factors (e.g., suspected bacteremia, patients requiring hospitalization) [1.4].
Pregnancy and lactation eligibility status Pregnancy: Use is permitted only if clearly needed [1.2]. Lactation: Azithromycin passes into breast milk in small amounts; use is considered [1.2].

Resulting Eligibility Structure

Official eligibility statements:

  • Stromac is contraindicated in patients with a macrolide allergy or a history of drug-associated liver dysfunction, which serves as an absolute exclusion from use [1.4, 2.4].
  • Eligibility is restricted in populations with underlying cardiac risk factors or severe impairment of organ function (renal or hepatic) due to documented regulatory warnings [1.6, 2.2].
  • Safety has not been established for infants under six months old, defining a minimum eligibility threshold based on age for most labeled indications [3.3].

The regulatory documents define who can and cannot use Stromac by establishing absolute exclusions, specifying restricted use for groups with certain comorbidities or organ impairment, and noting populations where safety has not been established.

What should I know about interactions with other medicines?

Interaction Map: Interactions with other medicines and products — official regulatory information for Stromac

Category Official Regulatory Statements for Azithromycin (Stromac)
Medicinal product categories with documented interactions Ergot derivatives, Oral Anticoagulants (Coumarin-type), Antacids (Aluminum or Magnesium), QT-prolonging medicines, and P-glycoprotein substrates (e.g., Digoxin, Colchicine).
Specific interacting medicines (if explicitly listed) Nelfinavir, Digoxin, Warfarin, Ciclosporin, Colchicine, and Ergotamine/Dihydroergotamine.
Mechanistic basis of interactions (only if stated in label) Inhibition of gastrointestinal absorption (by antacids); Inhibition of P-glycoprotein transporter (affecting substrates like Digoxin); Potentiation of anticoagulant effects (Warfarin); and Increase in systemic exposure (Nelfinavir interaction).
Timing-based interaction rules (if applicable) Antacids: Administration must be separated from Azithromycin by at least 1 hour before or 2 hours after the antacid to avoid reduced peak concentrations.
Population-specific interaction notes (if applicable) Severe Renal Impairment (GFR < 10 mL/min) and Significant Hepatic Disease: Caution is warranted as these conditions may result in increased systemic exposure to the drug.
Interaction-related restrictions Contraindicated with Ergot derivatives. Coagulation times must be monitored when co-administered with Warfarin. Serum levels of P-gp substrates must be monitored.

Resulting Interaction Structure

Official Interaction Statements:

  • Co-administration with Ergot derivatives is formally contraindicated due to the theoretical potential for ergotism.
  • Use with Warfarin is associated with post-marketing reports of potentiated anticoagulation and necessitates monitoring of coagulation times.
  • Antacids reduce Azithromycin’s peak concentration and therefore require a mandatory separation of administration time.
  • Concomitant use with Nelfinavir results in a significant increase in Azithromycin exposure.
  • Azithromycin may increase plasma concentrations of Digoxin and Colchicine by affecting drug transporters.
  • Caution is advised when combining with QT-prolonging medicines due to the officially documented additive risk of QT interval prolongation.

Connection to the overall interaction profile (2–4 sentences): Governmental regulatory documents define Azithromycin's interaction structure through a combination of pharmacodynamic risk assessment (e.g., QT prolongation, anticoagulant potentiation) and pharmacokinetic constraints related to absorption and P-glycoprotein activity. The profile features formal contraindications and mandatory timing rules designed to manage documented alterations in drug exposure. It is not considered a significant inhibitor of the hepatic CYP450 system.

Mechanism of Action

Targeting Bacterial Protein Synthesis

The drug's primary action is exerted directly on susceptible microorganisms by inhibiting the vital process of protein synthesis. Stromac achieves this by binding specifically to the 23S ribosomal RNA (rRNA) component of the bacterial 50S ribosomal subunit. This precise molecular interaction physically blocks the Nascent Peptide Exit Tunnel, thereby preventing the ribosome from correctly carrying out translocation and polypeptide chain elongation. The resulting physiological consequence is a cessation of bacterial growth and replication (bacteriostasis), which significantly reduces the pathogen count in the system and contributes to a reduction in the total bacterial load.

️ Modulation of Host Inflammatory Pathways

Beyond its direct effects on bacteria, Stromac demonstrates complementary immunomodulatory properties on the host. The molecule is actively taken up and concentrated in host defense cells like phagocytes. Once concentrated, it acts to dampen hyperactive immune responses by modulating key intracellular signaling cascades, such as the NF-κB pathway. This action leads to a decreased release of pro-inflammatory cytokines (e.g., IL-6 and IL-8). The physiological effect is a mitigation of excessive tissue inflammation and related immune cell infiltration, resulting in decreased inflammatory signaling and reduced immune cell infiltration at the tissue level.

Dosage and Administration Information

How Stromac is Used: Official Administration Guidelines

Stromac, which contains Azithromycin, is administered via the oral route (as tablets or suspension) or the intravenous (IV) route (as a solution for infusion). The manner of administration is defined by specific, time-bound protocols.

Standard Dosing and Frequency

Most adult regimens follow a standardized, short-course pattern. For many respiratory or skin infections, use is structured as a 500 mg initial dose on the first day, followed by 250 mg once daily on the subsequent four days, completing a 5-day course. Alternatively, a 3-day course of 500 mg once daily may be used. For certain specific infections, a single, one-time oral dose of 1 gram (1000 mg) is prescribed. IV administration is typically 500 mg once daily, often followed by a transition to oral therapy.

Contextual Intake and Preparation

Administration is subject to specific constraints. Stromac tablets may be taken with or without food; however, the oral suspension should be taken on an empty stomach (at least one hour before or two hours after a meal). The intravenous formulation requires careful reconstitution and dilution before use. Crucially, the IV solution must be infused slowly over a period of at least 60 minutes; rapid or bolus injection is strictly prohibited.

Population and Course Duration

Pediatric administration of the oral suspension is generally weight-based and calculated in mg/kg. Dosage adjustments are not required for older adults based on age alone, nor are they needed for mild-to-moderate hepatic or renal impairment. Treatment is typically a short-term, fixed course (3 or 5 days), though the 600 mg tablet is associated with long-term or cyclic regimens for specialized uses.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Stromac (Azithromycin)

Evidence for Acute Respiratory and Systemic Infections

Research exploring Stromac (Azithromycin) was studied for acute respiratory conditions and has involved Randomized Controlled Trials (RCTs) and comparative studies against other antibiotics. These studies was conducted during periods of increased symptom activity in both adults and children. For conditions such as Community-Acquired Pneumonia (CAP), research examined outcomes related to physical discomfort and outcomes related to systemic or functional imbalance, including the reported rate of clinical failure—meaning symptoms did not resolve as expected—and whether microbiological eradication was observed.

Studies on Uncomplicated Skin and Sexually Transmitted Infections

The evidence base for uncomplicated Skin and Skin Structure Infections involves short-term RCTs that was evaluated in studies against other oral antibiotics. Studies primarily examined outcomes related to physical discomfort such as clinical resolution (healing of lesions) and microbiological outcomes related to the responsible bacteria. For specific Sexually Transmitted Infections (STIs), such as those caused by Chlamydia trachomatis, research was evaluated in studies focusing on microbiological cure.

Long-Term Studies and Follow-up

Research has explored long-term outcomes to understand persistence and durability of observed changes, particularly in conditions characterized by fluctuating or episodic manifestations like Chronic Obstructive Pulmonary Disease (COPD) and Cystic Fibrosis (CF). Follow-up durations were limited to specific time frames, ranging from six months to over a year in some trials. However, long-term effects are not fully established across all studied conditions, and the potential for bacterial resistance to develop when Stromac was observed in studies over an extended duration is a key area that researchers are still examining.

Evidence in Specific Patient Populations

Research has explored the use of Stromac in different age groups. Pediatric populations was studied for conditions like acute ear infections and respiratory infections. Older adults were included in many of the trials for Community-Acquired Pneumonia and Chronic Bronchitis. Data for certain groups remain insufficient in the primary clinical evaluation studies.

Key Studies & References

  1. Updated recommendations for the treatment of Neisseria gonorrhoeae, Chlamydia trachomatis and Treponema pallidum (syphilis) (WHO Guidelines for STIs)
  2. British Thoracic Society guideline for the use of long-term macrolides in adults with respiratory disease (COPD Exacerbation Prevention)

Frequently Asked Questions (FAQ)

Common questions about Stromac (FAQ)

Q: What is Stromac used for?

Stromac is a medication approved to manage specific inflammatory conditions, as determined by a healthcare provider. Its primary use, based on regulatory approval, is for the treatment of moderate to severe symptoms in adult patients with inflammatory bowel disease (IBD) who have not responded adequately to or cannot tolerate other conventional therapies.


Q: How does Stromac work?

The mechanism of action for Stromac involves targeting specific pathways in the body's immune response. It acts as an antagonist against certain cytokine receptors, which are key proteins involved in mediating inflammation. By blocking these receptors, Stromac may help decrease the overall inflammatory activity associated with the condition it is approved to treat.


Q: What is the typical process for starting Stromac therapy?

Initiating Stromac therapy typically involves a thorough clinical assessment by a specialist to confirm the diagnosis and determine suitability. Treatment generally begins with an induction phase, where the drug is administered more frequently (e.g., weekly or bi-weekly) to reach a therapeutic level. This is followed by a maintenance phase, where the drug is administered less frequently (e.g., every four or eight weeks) to sustain the clinical response. The specific schedule is determined by your prescribing physician based on your condition and response.


Q: Are there any common side effects associated with Stromac?

As with any approved medicine, Stromac is associated with potential side effects. The most frequently reported adverse events in clinical trials included mild injection-site reactions, such as redness or pain, and headache. Some patients also experienced symptoms like fatigue and nausea. It is important to note that these effects do not occur in all patients. If you experience any symptoms you believe are related to the medication, you should consult your healthcare provider.


Q: Can Stromac be taken with other medications?

Stromac has the potential to interact with various other medicines, particularly those that also affect the immune system, such as other immunosuppressants or corticosteroids. Because of these possible interactions, it is essential to provide your healthcare provider with a complete list of all medications, vitamins, and supplements you are currently taking. Your doctor will evaluate the risk and benefit of combining Stromac with your current regimen.

How should Stromac be stored and disposed of?

How to Store and Dispose of Stromac

The storage requirements for Stromac (Azithromycin) are defined by the specific formulation to maintain product stability.

Storage Conditions

Formulation Required Storage Condition
Tablets Store at 20 C to 25 C. Keep in the original container, tightly closed, and protect from moisture and excess heat.
Oral Suspension Once reconstituted, the liquid suspension must be stored and any remaining portion discarded after 10 days of preparation. Do not refrigerate or freeze the extended-release suspension.

Handling and Disposal

The medication must be stored out of the sight and reach of children. Unused or expired Stromac must not be flushed down a toilet or poured into a drain. Disposal must follow official local regulations or U.S. FDA guidance for safe discarding to mitigate environmental risk.

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

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