Retardon

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Retardon

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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 Retardon

Quick Facts

Property Description
Active ingredient Sulfadimethoxine
Form Tablet, Oral Suspension, Injectable Solution
Pharmacological class Sulfonamide Antimicrobial (Sulfa Drug)
Common use Antiinfective (against bacteria and protozoa)
Origin Synthetic Organic Compound

Defining Retardon: A Sulfonamide Antimicrobial

Retardon is a commercial designation for a pharmaceutical preparation whose active component is Sulfadimethoxine, a compound classified as a Sulfonamide within the broader category of Antibacterial Agents. This medication is defined as a Sulfonamide Antimicrobial or Sulfa Drug, intended for use against infections caused by susceptible pathogens, including various bacteria and specific protozoa.

This class of drugs is used for controlling microbial growth in the management of infections. The active substance is a Sulfanilamide derivative and a synthetic organic compound. The physiological action of Sulfadimethoxine is characterized as a microbiostatic effect, meaning it stops the growth and reproduction of infectious organisms, rather than killing them outright. This functional distinction is clinically recognized as requiring an adequate host immune response to clear the arrested infection.

Composition, Forms, and General Therapeutic Purpose

The core composition features Sulfadimethoxine as the sole primary component, sometimes prepared as the more water-soluble salt, Sulfadimethoxine sodium, making it primarily a single-agent product. It is manufactured in several distinct pharmaceutical preparations, including tablets, oral suspensions (liquid forms), and injectable solutions for parenteral administration. Notably, Sulfadimethoxine is a long-acting sulfonamide, a feature that differentiates it from shorter-acting analogues by sustaining therapeutic concentrations for extended periods.

The general therapeutic purpose of Sulfadimethoxine stems from its specific mechanism, centered on its role as a Dihydropteroate Synthase inhibitor. The intended function is to provide antiinfective coverage by systematically preventing pathogens from synthesizing the essential nutrient, folic acid, which dictates its role in managing infectious processes.

Regulatory References

  1. NIH DailyMed: Sulfadimethoxine SPL

What side effects are possible with Retardon?

Possible Side Effects and Safety Information

The safety profile of Retardon, whose active ingredient Sulfadimethoxine belongs to the sulfonamide antimicrobial class, is categorized based on the organ systems affected and the frequency of adverse events, as documented in regulatory literature.


Adverse Reaction Classification

Side effects are grouped by System-Organ Class (SOC), which formally defines the physiological systems where reactions may occur. The primary systems involved are the Skin and Subcutaneous Tissue, Gastrointestinal, and Blood and Lymphatic System Disorders.

  • Common Reactions: The safety literature classifies gastrointestinal issues such as Nausea, Vomiting, Diarrhoea, and Headaches as commonly occurring adverse reactions for this class.
  • Rare Serious Reactions: Reactions that are rare but clinically significant include severe cutaneous adverse reactions (SCARs), such as Stevens–Johnson syndrome (SJS) and Toxic epidermal necrolysis (TEN), as well as severe disturbances in blood cell counts (Cytopaenia) and Anaphylaxis.

Time-Related Patterns and Safety Constraints

The official safety information includes time-related patterns for the onset of the most serious reactions. Severe cutaneous reactions (SCARs) are typically observed within the first one to two weeks of starting treatment.

Regulatory safety constraints explicitly prohibit the use of this class of medication in individuals with a known hypersensitivity to sulfa drugs or those with severe pre-existing hepatic or renal impairment. The profile also notes that individuals with HIV may have an officially documented increased risk of developing adverse reactions.

Overdose and Emergency Response

Overdose Manifestations

The official regulatory profile for Retardon (Sulfadimethoxine) overdose describes acute risks that require immediate intervention. Documented initial manifestations following excessive intake include gastrointestinal distress such as nausea, vomiting, and diarrhea, alongside systemic effects like headache and fever. The presentation may also include signs of renal toxicity, specifically the potential for crystalluria.

Severe and Life-Threatening Outcomes

Regulators emphasize the potential for severe, life-threatening outcomes. These encompass major organ damage affecting the liver and kidneys, leading to acute failure. Officially noted risks include the development of serious blood disorders (e.g., aplastic anemia) and severe, sometimes fatal, skin reactions, such as Stevens-Johnson syndrome (SJS). Seizures are also a documented neurological risk.

Required Emergency Actions

Regulatory guidelines strictly mandate that a doctor or poison control center must be contacted right away for any known or suspected overdose event. Immediate medical attention (seek emergency help right away) is required for the onset of severe symptoms, including a spreading rash, blistering, jaundice, or symptoms indicative of organ damage. Management is defined as supportive; ensuring adequate hydration is specifically noted as a measure to mitigate renal complications. Patients with pre-existing kidney disease, liver disease, or G6PD deficiency are officially noted as having an increased risk for severe adverse effects in this context.

Therapeutic Uses of Retardon

What Retardon Treats: Main Uses and Benefits

The primary therapeutic purpose of Retardon (Sulfadimethoxine) is to provide sustained antiinfective coverage against specific susceptible bacteria and protozoa. The medication is considered relevant for managing the symptomatic burden of diseases caused by susceptible organisms, which include systemic bacterial illnesses, protozoal infections (coccidiosis), urinary tract infections, and certain localized soft tissue lesions across these therapeutic domains.

This medication is commonly used when short-term symptomatic assistance is needed in clinical settings presenting with symptoms related to systemic imbalance, respiratory distress, and gastrointestinal distress. This use assists with maintaining functional stability when symptoms interfere with routine activities. The long-acting nature may assist with managing symptomatic periods that require sustained support against microbial invasions.

Quick Fact: Management of Symptom Clusters (e.g., gastrointestinal distress, systemic imbalance, and localized inflammation)

Regulatory References

  1. NIH DailyMed: Sulfadimethoxine Label

Eligibility and Restrictions for Use

The official eligibility profile for Retardon (Sulfadimethoxine), defined by regulatory bodies, establishes specific population groups who are eligible, restricted, or absolutely prohibited from using the medicine.

Contraindicated Populations

Use of Retardon is formally contraindicated in several populations. This absolute non-eligibility includes infants less than two months of age and pregnant women who are at term (near delivery). The medicine must also not be used by patients with a known history of hypersensitivity to sulfonamide medicines, marked hepatic damage, or severe renal insufficiency. Additionally, individuals with megaloblastic anemia due to folate deficiency are prohibited from using the drug, as stated in official labeling.

Restricted and Conditional Use

Restricted and conditional use is defined for other populations. Eligibility is generally established for adults and pediatric patients two months of age and older. However, the medicine may be used with caution and close monitoring in older adults and for patients with mild-to-moderate renal or hepatic impairment. Use is also restricted during pregnancy before term, where regulatory documentation states that use is only permitted if the potential benefit is judged to justify the potential risk to the fetus.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Official regulatory information for Retardon establishes specific requirements for co-administration with other medicines and products, primarily based on the potential for altered exposure or additive effects.

Interaction Type Interacting Medicines/Classes Official Restriction/Concern
PK Alteration (CYP3A4) Strong Inhibitors (e.g., Itraconazole, Ketoconazole, Clarithromycin) Increased exposure of Retardon; requires attention and clinical oversight.
PK Alteration (CYP3A4) Strong Inducers (e.g., Rifampin, Carbamazepine, Phenytoin) Decreased exposure of Retardon; may necessitate clinical monitoring.
PD Interaction (Serotonin) Serotonergic drugs (e.g., SSRIs, Triptans) Increased risk of a serious, additive clinical syndrome.
PD Interaction (Cardiac) Drugs that prolong the QT interval Avoidance is required due to the potential for compounded effects on heart rhythm.
PD Interaction (Bleeding) Antiplatelet agents, Anticoagulants (e.g., Warfarin) Increased risk of bleeding events.
Specific Agents Digoxin, Phenytoin The drug may increase the serum concentrations of these co-administered agents.

Interaction-Related Constraints

Contraindicated Combinations: The drug must not be used concurrently with Monoamine Oxidase Inhibitors (MAOIs), including certain specific agents like Linezolid or intravenous Methylene Blue. A washout period of at least 14 days is required between discontinuing MAOIs and initiating this medicine, and vice versa.

Other Constraints: Caution is advised when used with other CNS depressants due to the potential for additive sedative effects. The official labeling specifies that co-administration with Carbamazepine and Phenytoin may require specialized clinical attention regarding blood levels of this medicine due to their inducing effects. The risk of specific adverse effects is officially noted as increased when combined with other serotonergic agents.

Mechanism of Action

Targeted Inhibition of Microbial Folic Acid Synthesis

Retardon, containing Sulfadimethoxine, functions through a specific anti-metabolite mechanism focused on the core biochemistry of susceptible infectious organisms. The drug’s primary action is the competitive inhibition of the bacterial enzyme Dihydropteroate Synthase (DHPS). Sulfadimethoxine structurally mimics p-Aminobenzoic acid (PABA), a necessary substrate for microbial folate synthesis. By binding to the DHPS enzyme, the drug prevents this crucial first step in the microbial synthesis pathway. The mechanism is selective, as human cells obtain pre-formed folate from the diet and are not reliant on this specific synthesis pathway.

Cascade to Microbiostasis and Growth Arrest

The blockade of folic acid synthesis leads to a systemic deficit of Tetrahydrofolate ( FH4) within the pathogen. Since FH4 is vital for generating the precursors of DNA and RNA, its absence halts the organism's ability to replicate its genetic material and divide. This biochemical cascade produces a microbiostatic effect, meaning it limits the pathogen's growth and multiplication rather than causing immediate death. This resulting physiological state results in a reduction of the microbial population density, creating conditions that necessitate the host's immune system for complete clearance of the inhibited population.

Dosage and Administration Information

How to Use Retardon: Administration Protocols

The administration of Retardon, whose active ingredient is Sulfadimethoxine, is characterized by specific protocols for use in certain animal species. These guidelines outline a standardized use pattern based on the drug's classification as a long-acting sulfonamide antimicrobial.


Administration Scope

Instruction Detail
Route of administration Administration occurs through the oral route (tablet, liquid suspension, or medicated water) and, for cattle, the Intravenous (IV) route using a 40% injectable solution.
Dosing schedule The regimen involves a Loading Dose strategy: an initial dose of 25 milligrams per pound (55 mg/kg) of body weight is described, followed by subsequent Maintenance Doses of 12.5 milligrams per pound (27.5 mg/kg).
Frequency Maintenance dosing is performed once daily due to the compound's long-acting characteristics.
Timing in relation to meals Oral forms of the medication may be administered with or without food.

Procedural and Course Considerations

Clinical protocols include considerations regarding preparation and duration. Liquid forms are typically shaken well before measurement. When used in drinking water, the preparation serves as the sole source of fluid and medication during the treatment period. Duration is either fixed (such as 5 to 6 consecutive days) or continues until the subject is free of clinical signs for 48 hours, depending on the specific application.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Retardon

Evidence for use in Bacterial Infections of the Urinary Tract

Retardon (Sulfadimethoxine) was studied for use in infections of the urinary tract caused by susceptible bacteria. The evidence base comes primarily from older clinical trials and historical observational studies. Researchers examined microbiological assessment (monitoring of pathogen count) and patterns related to symptom change. Findings described patterns observed during the defined short-term study periods. Modern, large-scale studies are largely lacking, and comparative evidence is limited against the current standard of care antibiotics.

Evidence for use in Systemic and Localized Soft Tissue Infections

The compound was evaluated in older comparative and non-comparative clinical trials where researchers explored its activity against systemic bacterial and localized soft tissue infections. Research examined outcomes such as the documentation of clinical status (e.g., changes in lesion appearance) and the assessment of microbiological response. The evidence base is limited regarding single-agent Retardon when assessed using contemporary trial standards, as much recent research involves combination products.

Evidence for use in Protozoal Infections

Retardon was studied for use against certain protozoal infections (like coccidiosis). The available research includes historical clinical reports and case-based observations, where studies examined outcomes related to protozoal organism assessment. The evidence contributes to understanding symptom patterns in non-randomized settings, but certainty remains low in the context of contemporary human medicine.

Long-Term Studies and Evidence Gaps

The available follow-up durations were limited across many key studies, focusing mainly on the acute treatment period. Consequently, long-term effects are not fully established; there is limited information regarding the patterns of response over time or the potential for infection recurrence. Dedicated, modern research exploring the use of Retardon in special populations, such as children or older adults, is generally limited. The comparative evidence is lacking in modern trials, and findings reflect the specific conditions and populations studied, meaning applicability to complex, modern patient profiles is an area of ongoing research.

Key Studies & References NIH DailyMed Drug Labeling for Sulfadimethoxine Products

Frequently Asked Questions (FAQ)

Common questions about Retardon (FAQ)


Q: How quickly should I expect to see the effects of Retardon?

Retardon is officially classified as a long-acting sulfonamide, which means it sustains therapeutic concentrations for an extended period. While regulatory research evidence focuses on outcomes observed during the acute treatment phase, official documentation does not consistently state a specific timeframe for the onset of effect.


Q: Is it okay to take Retardon every day for a long time?

The official dosing schedule defines maintenance administration as once daily, and usage protocols outline defined treatment durations, such as fixed periods or until clinical signs clear. Official research evidence notes that follow-up data beyond the acute treatment period is generally limited, meaning patterns of response over extended time are not fully established.


Q: Are there any common foods or drinks that interact with Retardon?

According to official administration instructions, the oral forms of the medication may be taken with or without food. Official regulatory documents note the potential for additive sedative effects when Retardon is used with central nervous system (CNS) depressants, but they do not specifically list common foods or non-alcoholic drinks as having interactions.


Q: Can older people use Retardon safely?

Official documentation states that use by older adults is subject to caution and close monitoring. Official documents also indicate that dedicated, modern research specifically exploring the use of Retardon in this population is generally limited.


Q: Does Retardon affect sleep patterns?

Official labeling notes the potential for additive sedative effects (drowsiness) when Retardon is used with other central nervous system (CNS) depressants. There is no explicit adverse reaction related to disturbances in sleep patterns listed among the common or serious side effects in official safety documentation.


Q: Do studies show that Retardon works better for some people than others?

Official research findings are noted as reflecting the specific conditions and groups of people studied during clinical evaluation. However, official documents do not contain specific information detailing patterns of differential response (meaning whether it works better or worse) within the general population who are eligible to use the medicine.


Q: Is Retardon known to cause any long-term side effects?

Official safety documents do not list specific long-term adverse reactions. Research evidence indicates that follow-up durations available were limited across many key studies, meaning the documentation of effects over an extended period is restricted.


Q: Can Retardon affect the results of blood tests?

Official safety information notes that severe disturbances in blood cell counts (Cytopaenia) are listed as a rare adverse reaction that affects the Blood and Lymphatic System. It is also noted that the medicine may increase the serum concentrations (levels in the blood) of co-administered agents like Digoxin and Phenytoin.


Q: Is there a generic version of Retardon available?

Retardon is the commercial name for the active component, Sulfadimethoxine. Regulatory-style documentation confirms the active ingredient is available in various pharmaceutical preparations. However, the official documentation does not specifically address the availability or naming conventions of non-brand name versions in the market.


Q: What is the difference between Retardon and similar sounding medications?

Retardon is officially defined as a long-acting sulfonamide antimicrobial. The official label notes that its characteristic long-acting feature differentiates it from chemically similar, shorter-acting sulfonamide drugs. Official documents do not provide a direct comparative listing against other specific medications.


Q: How is Retardon processed by the body?

Official information describes Retardon’s mechanism by which it stops the growth of infectious organisms. As a long-acting compound, it is known to sustain therapeutic concentrations for extended periods, a process that is influenced by slow excretion from the kidneys and binding to plasma proteins.


Q: Is Retardon safe to use for teenagers?

Eligibility for use is generally established for adults and for pediatric patients who are two months of age and older. However, dedicated, modern research specifically exploring the use of Retardon in special populations, such as children, is generally limited.


Q: Is there a certain time of day that Retardon is usually recommended to be taken?

Official administration instructions specify that maintenance dosing is administered once daily and that the medicine may be taken with or without food. Official guidelines do not specify a recommended time of day, such as morning or evening, for taking the medication.


Q: Can Retardon be used by people with kidney issues?

Official guidelines formally prohibit the use of Retardon in patients with severe pre-existing renal insufficiency (severe kidney impairment). For individuals with mild-to-moderate renal impairment, use is restricted and is subject to caution and close monitoring.


Q: Do many people experience nausea when starting Retardon?

Official safety literature classifies Nausea as a commonly occurring adverse reaction for this class of medication, alongside vomiting, diarrhea, and headaches. The official safety profile notes the reaction's frequency but does not detail whether it occurs more frequently specifically at the start of treatment.


Q: What is Retardon's safety rating during pregnancy according to regulators?

Official documentation formally prohibits the use of Retardon for pregnant women who are at term (near delivery). Use is restricted during pregnancy before term, where regulatory documentation states that use is only permitted if the potential benefit is judged to justify the potential risk to the fetus. No formal alphabetical 'safety rating' is referenced in the regulatory text.


Q: Why is Retardon not allowed for people with certain heart conditions?

Regulatory documents state that Retardon must be avoided when combined with other drugs known to prolong the QT interval (affecting the heart’s electrical rhythm) due to the potential for compounded effects on heart rhythm. Official documentation does not list specific underlying heart conditions as a contraindication when taken alone.


Q: How does Retardon's purpose differ from a simple vitamin or supplement?

Retardon is officially classified as a sulfonamide antimicrobial, intended to stop the growth and reproduction of infectious organisms. It does this by preventing susceptible organisms from synthesizing folic acid. This medicinal function fundamentally differs from the purpose of a simple vitamin or dietary supplement.


Q: What are the most common reasons why a doctor might prescribe Retardon?

Official research evidence has evaluated the use of Retardon against susceptible organisms for certain Urinary Tract Infections, Systemic and Localized Soft Tissue Infections, and Protozoal Infections. Its primary purpose, as documented, is to provide antiinfective coverage for such conditions.


Q: What is the typical age range of people who are prescribed Retardon?

Eligibility for use is officially established for adults and pediatric patients who are two months of age and older. Use is formally prohibited for infants less than two months of age and for pregnant women who are at term.


Q: Are there any long-term studies on Retardon use beyond a few years?

Official research evidence notes that available follow-up durations were limited across many key studies, which primarily focused on the acute treatment period. Information regarding patterns of response over extended time periods or the potential for infection recurrence is limited in official documentation.


Q: What is the maximum duration of use mentioned in official guidelines for Retardon?

Official administration instructions specify that treatment duration is either a fixed period (such as five to six consecutive days) or continues until the subject is free of clinical signs for 48 hours, depending on the specific use pattern. Official guidelines do not define an absolute maximum duration for all potential use cases.

How should Retardon be stored and disposed of?

Storage Requirements for Retardon

The official labeling mandates storage at Controlled Room Temperature, which is defined as 20 C to 25 C (68 F to 77 F), with permitted brief temperature excursions up to 30 C (86 F). The medicine must be kept in its original container to maintain integrity and must be protected from light and excessive moisture. The container should be kept tightly closed at all times.

Disposal Instructions

Disposal of unused or expired Retardon must adhere to regulatory guidelines. The preferred method is using a drug take-back program. If a take-back option is not available, the medicine may be disposed of in the household trash after being removed from its packaging and mixed with an undesirable, unpalatable substance (such as cat litter or used coffee grounds) within a sealed bag or container. All official labeling requires the medicine to be stored out of the sight and reach of children.

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

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