Synulox

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Medically reviewed

Laura Arias

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 Synulox

Property Description
Active Ingredients Amoxicillin and Clavulanic Acid
Pharmacological Class Potentiated Beta-Lactam Antibiotic (Potentiated Penicillin)
Common Use Bacterial Infections
Origin Semi-synthetic (Amoxicillin is semi-synthetic)
Primary Forms Palatable Tablets, Injectable Suspension

What Type of Medicine is Synulox?

Synulox is a prescription-only veterinary medicinal product classified as a potentiated penicillin or Beta-Lactam antibiotic. This drug is a potent semi-synthetic antimicrobial agent developed for use across species, particularly in dogs and cats, targeting a wide range of bacterial infections. Its generic combination, Amoxicillin and Clavulanic Acid, is clinically recognized for its critical role in combating strains resistant to traditional penicillins. The use of the trade name Synulox often refers to specific palatable tablets that are favored for easy oral administration to small animals.

The designation potentiated is central to its classification, indicating that the core antibiotic component has been strengthened by the addition of a second agent. This structural characteristic ensures the medication remains effective even against strains that have developed resistance to standard, single-agent penicillins.


Composition and Structure of the Combination Antibiotic

The drug's effectiveness relies on the synergistic combination of two distinct active ingredients: Amoxicillin and Clavulanic acid. Amoxicillin provides the core bactericidal activity, while Clavulanic acid acts as the necessary protective component. The addition of Clavulanic Acid significantly increases the potency of the Amoxicillin component.

This fixed-dose product is supplied in various dosage forms, including the characteristic pink, circular Palatable Tablets and the sterile Injectable Suspension (parenteral preparations). The purpose of combining these two substances is to ensure the Amoxicillin component remains chemically stable and fully active against the target bacteria throughout its intended action.


High-Level Purpose of the Potentiated Action

The general purpose of this specific combination is to overcome bacterial defense mechanisms, resulting in broad-spectrum bactericidal activity to effectively resolve underlying infections. Bacteria that have acquired resistance often produce Beta-Lactamase enzymes that chemically destroy penicillin-class drugs. The Clavulanic acid component, classified as a Beta-Lactamase inhibitor, specifically disables these protective bacterial enzymes, safeguarding the Amoxicillin and ensuring its ability to inhibit bacterial cell wall formation. This robust, potentiated action is essential for successfully resolving infections caused by susceptible organisms.

Regulatory References

  1. DailyMed Monograph for Amoxicillin and Clavulanate Potassium

What side effects are possible with Synulox?

Possible side effects and safety information

This section describes the adverse reactions and safety characteristics of the Amoxicillin and Clavulanic Acid combination as documented in official government regulatory sources, such as the FDA Prescribing Information and the EMA Summary of Product Characteristics (SmPC).

Frequency and System-Organ Classification

The safety profile is primarily characterized by gastrointestinal effects. According to official regulatory frequency classifications, diarrhea is documented as a very common adverse reaction. Other common effects include nausea, vomiting, and mucocutaneous candidosis. Less common effects, classified as uncommon, include dizziness, headache, and increases in liver enzymes (AST and/or ALT), alongside skin reactions such as rash and urticaria.

Adverse reactions are grouped by physiological systems, including Gastrointestinal Disorders, Hepatobiliary Disorders, Skin and Subcutaneous Tissue Disorders, and Blood and Lymphatic System Disorders.

Serious Adverse Reactions and Safety Constraints

Official labeling highlights the potential for several serious adverse reactions, which are classified as rare or not known in frequency. These include severe allergic reactions such as anaphylaxis and rare but serious skin conditions like Stevens-Johnson Syndrome (SJS). Clinically significant hepatic events, including cholestatic jaundice and hepatitis, are also documented safety concerns.

Regulatory documents outline specific constraints: the medication is contraindicated for individuals with a history of a severe hypersensitivity reaction to any penicillin. Caution is also necessary in patients with renal or hepatic impairment, as adverse events, including convulsions, may occur in these populations. Hepatic events are sometimes reported to occur after treatment has ceased, indicating a time-related safety pattern that extends beyond the period of use.

Overdose and Emergency Response

Overdose and When to Seek Help

The official regulatory profile for an overdose of Amoxicillin and Clavulanic Acid focuses on documented acute clinical manifestations and mandated emergency actions. All suspected overdoses require immediate professional assistance.

Documented Manifestations and Severe Outcomes

An overdose is primarily associated with pronounced gastrointestinal symptoms, including abdominal pain, vomiting, and severe diarrhea. These effects carry a potential risk of fluid and electrolyte imbalance.

A more serious concern documented in official labeling is the potential for Amoxicillin crystalluria within the urinary tract. This condition may lead to changes in urine output, such as bloody or cloudy urine, and carries the risk of progressing to oliguric renal failure.

In high-dose exposure or in individuals with pre-existing impaired renal function, Central Nervous System (CNS) effects are documented, most notably the occurrence of convulsions or seizures.

Regulator-Mandated Emergency Actions

It is a requirement set forth in official regulatory documents that immediate medical attention must be sought in all cases of suspected overdose. Should an individual collapse, experience a seizure, exhibit difficulty breathing, or be unable to be awakened, emergency services must be contacted immediately.

Treatment for an overdose is explicitly defined as symptomatic and supportive, with a specific focus on maintaining adequate hydration to mitigate the risk of crystalluria. While no specific antidote is known, both active components can be removed from the bloodstream by hemodialysis.

Therapeutic Uses of Synulox

What Synulox Treats: Main Uses and Benefits

This medication is an antibiotic combination that addresses bacterial infections across several key systems. It contributes to easing the overall symptom load and supports patients during difficult episodes where short-term, robust symptomatic assistance is needed. The combination of active ingredients is relevant for managing conditions that affect multiple systems, including infections of the lower respiratory tract, acute otitis media, sinusitis, skin and skin structures, and the urinary tract.


Key Therapeutic Focus

The drug is commonly applied in scenarios where symptoms become more noticeable, such as during flare-ups of chronic conditions or sudden acute infections. It is used for managing symptoms related to visible and often painful bacterial conditions. It helps address symptom clusters that create noticeable functional strain and is applied in addressing symptom clusters related to physical discomfort. It is applicable within clinical settings that involve acute or disruptive symptom patterns.


Quick Facts

  • Relief for Symptom Clusters: This medication is often relevant for managing symptoms that interfere with daily comfort caused by bacterial colonization.
  • Support for Recurrent Manifestations: It is considered relevant when short-term symptom management is appropriate for conditions involving recurrent or episodic manifestations.

Eligibility and Restrictions for Use

Who Can and Cannot Use Synulox?

The population eligibility for Amoxicillin and Clavulanic Acid (the active ingredients in Synulox) is strictly defined by government regulatory labeling, focusing on specific contraindications and patient conditions.

Absolute Contraindications

Official prescribing information prohibits the use of this medicine in the following groups:

  • Patients with a history of serious hypersensitivity reactions (e.g., anaphylaxis) to amoxicillin, clavulanate, or any other beta-lactam antibacterial drug (e.g., penicillin or cephalosporins).
  • Patients with a previous history of cholestatic jaundice or hepatic dysfunction specifically associated with prior treatment using Amoxicillin/Clavulanate.

Condition and Age-Based Restrictions

Use is restricted or requires caution for other populations:

  • Organ Function: Patients with severe renal impairment (Creatinine Clearance < 30 mL/min) are contraindicated for the extended-release tablet formulation. Dose adjustments are required for immediate-release forms. Hepatic function should be monitored in patients with liver impairment.
  • Age Groups: Use is restricted in Infants and Neonates aged le 12 weeks (le 3 months). Older adults generally require no adjustment unless age-related renal issues are present.
  • Comorbidities: Use is generally avoided in patients with infectious mononucleosis. Specific formulations containing aspartame are restricted for patients with Phenylketonuria (PKU).
  • Reproductive Status: The medicine is categorized as Pregnancy Category B. Use is restricted to when it is clearly needed by the patient, and caution is advised during lactation.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Official regulatory documentation identifies specific patterns of interaction between the active components of this medicine, Amoxicillin and Clavulanic Acid, and other substances or medicinal products.

Contraindicated and Exposure-Altering Combinations

Substance Officially Documented Interaction Outcome
Probenecid Co-administration is not recommended due to inhibition of the renal tubular secretion of Amoxicillin, which results in increased and prolonged blood concentrations of the drug.
Bacteriostatic Antimicrobials The bactericidal effect of this medicine may be inhibited by the concurrent use of drugs classified as bacteriostatic agents (e.g., tetracyclines, macrolides).

Pharmacodynamic and Diagnostic Interactions

Co-administration with Oral Anticoagulants requires appropriate monitoring, as this combination may lead to an abnormal prolongation of prothrombin time (INR). Concomitant use with Allopurinol is documented to increase the likelihood of allergic skin reactions. The drug may also cause false-positive reactions in certain non-enzymatic methods for testing urine glucose and may potentially lead to a false-positive Coombs test.

Food Administration Requirements

Regulatory documents state that to ensure optimal absorption, the medicine should be administered at the start of a meal. Food intake is documented to enhance the absorption of the Clavulanate Potassium component.

Mechanism of Action

The activity of Synulox relies on the synergistic interaction of its two components to target and disrupt the integrity of susceptible bacterial cells.

️ Defeating Bacterial Resistance Through Potentiation

This domain covers the protective role of Clavulanic Acid, which acts as a suicide inhibitor by binding irreversibly to bacterial Beta-Lactamase enzymes. By neutralizing these defense enzymes, Clavulanic Acid prevents the chemical destruction of Amoxicillin, thereby allowing the antibiotic to engage its target in bacterial strains possessing those resistance mechanisms.

Covalent Inhibition of Cell Wall Synthesis

The primary destructive mechanism belongs to Amoxicillin, which acts by covalently binding to and inhibiting Penicillin-Binding Proteins (PBPs)—enzymes essential for the final cross-linking of the bacterial cell wall (peptidoglycan synthesis). This molecular disruption halts the formation of the rigid cell structure, leading to a loss of osmotic stability.

Pathogen Lysis and Bactericidal Effect

The mechanistic cascade culminates when the structurally compromised bacterial cell wall can no longer withstand the high internal pressure. This immediate physical failure results in osmotic lysis (the cell bursts), achieving the physiological consequence of bactericidal action.

Dosage and Administration Information

Official Administration Guidelines for Synulox

The following details the parameters for the correct use of Synulox (Amoxicillin/Clavulanic Acid).


Administration Scope

Entity Instruction
Route of Administration Oral Use (Palatable Tablets, Drops, Bolus); Injection (Intramuscular or Subcutaneous for dogs/cats; Intramuscular only for cattle/pigs); Intramammary Use (cows).
Standard Dosing Rate Oral: 12.5 mg/kg bodyweight total active ingredients per dose. Injection: 8.75 mg/kg bodyweight (e.g., 1 ml per 20 kg).
Dosing Frequency Oral Forms: Administered twice daily (every 12 hours). Injectable Form: Administered once daily.
Course Duration Routine Cases: 5 to 7 days. Chronic/Refractory Cases: May require longer courses, such as 10 to 28 days for chronic cystitis.

Preparation and Administration Specifics

  • Oral Administration: Tablets are often accepted directly or may be crumbled and added to a small quantity of food for immediate consumption. The Palatable Drops (Powder for Oral Suspension) must be reconstituted with water to the specified volume and shaken well before use. The reconstituted product must be stored in a refrigerator.
  • Injection: The vial of Ready-to-Use Suspension must be shaken well before use. The product is not suitable for intravenous (IV) administration. Following IM or SC injection, the administration site should be massaged.
  • Age-Group Rule: Oral administration is contraindicated in rabbits, guinea pigs, hamsters, and gerbils.

These instructions define the standardized, weight-dependent administration protocol. The correct use involves accurately calculating the dose based on kg body weight, selecting the approved route for the specific species and formulation, and strictly following the designated dosing frequency (e.g., twice daily for oral forms).

Recent Clinical Evidence

Research Evidence / Overview of Studies for Synulox

Evidence for Use in Skin and Soft Tissue Infections

This area of research was studied for its use in the management of infections of the skin and underlying soft tissues. The evidence primarily comes from short-term, controlled field studies where the drug combination was evaluated in the context of skin and soft tissue infections. Researchers monitored outcomes related to overall clinical assessment and measured the microbiological culture results of the targeted bacteria. The findings describe patterns observed in the studies related to changes in symptoms and microbiological culture results following treatment.

Evidence for Use in Urinary Tract Infections (UTIs)

The research examined its use in bacterial urinary tract infections. The evidence base includes a mix of controlled clinical trials and supporting PK/PD studies that analyzed drug concentration in the urinary system. Trials were evaluated in populations with different forms of UTIs, and researchers primarily examined the bacteriological culture results. Studies documented varying measurements of microbiological culture results depending on the specific bacterial strain and the duration of therapy employed. The certainty about the best approach for different types of UTIs remains low due to varying results regarding optimal treatment duration.

Evidence for Use in Respiratory Infections

Research was studied for its use in specific bacterial infections of the respiratory tract, often those associated with periods of heightened symptoms. Studies were evaluated in populations with community-acquired infections and acute flare-ups of chronic conditions. Researchers examined outcomes related to systemic or functional imbalance, such as measures of clinical recovery and the measurements of changes in breathing difficulties. Supporting PK/PD research was studied for the drug's concentration profiles in the lung tissues.


Long-Term Studies and Follow-Up Data

The majority of the research is focused on the acute phase of infection. Primary efficacy studies were observed in populations over defined time intervals, generally ranging from 7 to 30 days. Follow-up durations were limited after the treatment course ended. There is limited information for long-term outcomes that would describe what happens months or years after the use of the drug.

What is Still Uncertain About the Research

The research provides a framework for understanding the drug's clinical use, but several research limitation frames apply. Evidence quality varies across studies, with some indications relying on older field studies. Comparative evidence is lacking in some areas against the newest generation of antibiotics. Subgroup findings are often limited to the populations studied in the regulatory and peer-reviewed literature.

Key Studies & References

  1. DailyMed - Amoxicillin and Clavulanate Potassium Tablet Monograph
  2. Human Medicines Regulatory Agency (HMA) - Veterinary Medicines Database (VMD) - Summary of Product Characteristics (Amoxicillin/Clavulanic Acid)

Frequently Asked Questions (FAQ)

Common questions about Synulox (FAQ)


Q: How quickly should I expect Synulox to start working?

The medicine is designed to begin its bactericidal action shortly after administration. Official clinical studies often monitor for signs of improvement, such as symptom relief or evidence of bacterial clearance, within 48 to 72 hours of starting treatment. The regulatory guidance requires the full prescribed duration be completed to help ensure treatment success.

Q: What are the most commonly reported side effects?

According to official product information, the most frequently reported adverse reactions are related to the digestive system. These common effects include diarrhea, nausea, and vomiting. Skin rash is also one of the commonly reported side effects listed in regulatory documents.

Q: Can Synulox cause an allergic reaction, and what are the signs?

Official warnings indicate a risk of serious allergic reactions, including anaphylaxis, which requires immediate attention. Signs of a severe reaction can include swelling of the face, lips, tongue, or throat, or difficulty breathing. Official labeling states the medicine is contraindicated for individuals with a known history of severe hypersensitivity to penicillin-class drugs.

Q: Can the effectiveness of Synulox be reduced by other medications?

Regulatory documents describe that the drug's effectiveness may be affected by certain other medicines. For instance, its bactericidal effect may be inhibited by bacteriostatic antimicrobials. Co-administration with certain drugs, such as probenecid, is officially not recommended in regulatory documents because it increases and prolongs the concentration of amoxicillin in the blood.

Q: What kind of studies support the use of Synulox?

The use of the drug is supported by evidence derived from controlled clinical trials and field studies. These studies monitor clinical outcomes, such as symptom relief, and track microbiological culture results against the targeted bacteria. This research framework is used to establish the drug's effectiveness for its indicated uses.

Q: Is Synulox generally prescribed for short-term use only?

Yes, the official administration guidelines indicate that treatment courses are generally for short-term use. Routine cases typically involve courses ranging from 5 to 14 days. While longer courses may be required for specific chronic infections, they remain defined treatment periods.

Q: What level of evidence is there for Synulox's use in urinary tract infections?

The medicine is indicated for treating bacterial urinary tract infections (UTIs) and has been evaluated in clinical trials for this purpose. However, official information also notes that certainty regarding the optimal treatment duration for various types of UTIs can vary across studies.

Q: Can Synulox be used for skin infections?

Yes, the drug is officially indicated for the treatment of certain susceptible bacterial infections of the skin and underlying soft tissues. Official studies have specifically evaluated its use in this context.

Q: What happens if a dose of Synulox is missed?

Patient counseling information typically advises that a missed dose should be taken as soon as it is remembered. However, if it is almost time for the next scheduled dose, the missed dose should be skipped to prevent taking too much medicine at once. The counseling information emphasizes continuing the regular dosing schedule to avoid taking an excessive amount.

Q: Does Synulox interact with common pain relievers like ibuprofen?

Official regulatory documents list specific, major drug-drug interactions that are known to alter how the medicine works. These official documents do not typically include a warning for common, non-steroidal pain relievers like ibuprofen, suggesting no major interaction is documented.

Q: Is it necessary to finish the entire course of Synulox?

Official regulatory warnings state that the medicine is intended to be taken for the full prescribed course to reduce the development of drug-resistant bacteria and maintain effectiveness. Skipping doses or discontinuing treatment early may decrease the medicine's effectiveness.

Q: Are there any long-term side effects associated with Synulox use?

While most clinical studies focus on the acute phase of treatment, official labeling warns of the potential for hepatic events (liver issues), including cholestatic jaundice and hepatitis. These events have been reported to occur after the treatment course has ceased, indicating a safety concern that extends beyond the period of use.

Q: Is Synulox the same as co-amoxiclav?

Synulox is a registered trade name for a medicinal product that contains the active ingredients Amoxicillin and Clavulanic Acid. This generic combination is also commonly known as co-amoxiclav. Therefore, the active drug components are chemically the same combination.

Q: What is the difference between Synulox and penicillin?

Synulox is classified as a potentiated penicillin-class antibiotic. It differs from standard penicillin because it includes Clavulanic Acid, which acts as a protective agent. This agent prevents Amoxicillin from being destroyed by beta-lactamase enzymes, which are produced by many resistant bacteria.

Q: Does Synulox contain sulfa?

No. According to the official description of its components, the active ingredients are Amoxicillin and Clavulanic Acid. These ingredients are derived from the penicillin nucleus and do not contain sulfa.

Q: Is Synulox safe for people with kidney problems?

Official information notes that its use requires caution and is often restricted for patients with reduced kidney function. Patients with severe renal impairment may need dose adjustments, and certain extended-release forms may be officially contraindicated.

Q: Does taking Synulox cause dizziness or drowsiness?

Dizziness is documented as an uncommon adverse reaction in regulatory safety profiles. While drowsiness is not typically listed as a primary side effect, other related effects may impact alertness.

Q: Can Synulox be used to treat viral infections?

No. Regulatory information consistently states that this drug is an antibacterial agent. It is only indicated for treating infections that are proven or strongly suspected to be caused by susceptible bacteria, and it has no effect against viral infections.

Q: Does Synulox have an impact on the body's natural gut bacteria?

Yes, antibiotics are known to disrupt the normal, helpful bacteria in the gut. Adverse reactions like diarrhea and the risk of candidiasis (a yeast infection) are consequences of this disruption to the natural balance of gut flora.

Q: Do food or certain drinks affect how Synulox works?

Official documents state that taking the medicine at the start of a meal is recommended. Food has been shown to enhance the absorption of the clavulanate component of the drug. This method of administration also helps to minimize potential gastrointestinal intolerance.

Q: Is there a risk of developing yeast infections while on Synulox?

Yes, there is a documented risk. Mucocutaneous candidosis (a type of yeast infection) is listed as a common adverse reaction in the official safety profile. This occurrence is commonly reported with the use of broad-spectrum antibiotics.

Q: Are there any restrictions on driving while taking Synulox?

While official information does not typically impose a direct restriction on driving or operating machinery, caution is advised due to the potential for side effects like dizziness that may affect alertness.

Q: Does Synulox affect blood sugar levels?

Regulatory information notes that the medicine may cause false-positive reactions in certain non-enzymatic methods used for testing urine glucose. It is important for patients who monitor their blood sugar to be aware of this potential diagnostic interference.

Q: Can Synulox cause headaches?

Yes, headache is listed as an uncommon adverse reaction associated with the use of this medicine in official safety profiles.

Q: Is it common for Synulox to be prescribed for dental infections?

Yes, the drug is indicated for the treatment of infections caused by susceptible bacteria. This class of antibiotics is commonly used and officially indicated in regulatory documents for the treatment of certain bacterial infections related to the mouth and teeth.

Q: What is the role of Synulox in treating respiratory tract infections?

The medicine is officially indicated for the treatment of certain susceptible bacterial infections involving the lower respiratory tract. Clinical studies have specifically evaluated its effectiveness and concentration profiles in lung tissues for this purpose.

Q: Does Synulox have any known interaction with alcohol?

According to official regulatory sources, there is no known direct or major chemical interaction between the drug and alcohol. However, alcohol consumption may worsen common adverse reactions like nausea, vomiting, or dizziness, which can occur while taking the medicine.

Q: How long does Synulox stay in your system after the last dose?

Pharmacokinetic studies indicate that the half-life (T1/2) of the active components is relatively short, approximately 1 to 1.3 hours. The components are largely eliminated from the body within a day after the final dose.

Q: What is the purpose of the potassium salt in Synulox?

The clavulanic acid component is chemically combined with potassium to form clavulanate potassium. The addition of the potassium salt makes the component stable and increases its bioavailability, ensuring the drug can be properly absorbed and used by the body.

Q: Do any official warnings exist regarding prolonged use of Synulox?

Yes, official warnings caution against the potential for microbial overgrowth or superinfections with non-susceptible organisms. The prolonged use of antibiotics increases the risk of conditions like yeast infections or C. difficile-associated diarrhea.

Q: Is Synulox a broad-spectrum antibiotic?

Yes, official classification describes the active drug combination as a broad-spectrum antibiotic. This means it is active against a wide range of both gram-positive and gram-negative microorganisms due to the protective effect of clavulanic acid.

Q: Can Synulox affect birth control pills?

Official regulatory information indicates that, in common with other broad-spectrum antibiotics, this medicine may potentially reduce the effectiveness of oral contraceptives. This potential interaction is documented in official information.

How should Synulox be stored and disposed of?

Regulatory documents define mandatory conditions for the storage and disposal of Synulox. All formulations, including Palatable Tablets and the Ready-to-Use Suspension, must not be stored above 25 C. The tablets require storage in a dry place, and all products must be stored out of the sight and reach of children.

Requirement Storage Rule Stability Rule
Temperature Do not store above 25 C; Powder for Oral Suspension must be refrigerated (2 C–8 C) after reconstitution. Any reconstituted oral suspension remaining 7 days after preparation must be discarded.
Handling/Stability The injectable suspension is moisture sensitive; a completely dry syringe is required for extraction. Do not use material showing dark brown discoloration. Injectable contents must be used within 28 days after first opening (broaching), with unused material discarded.

All unused Synulox products, or waste materials derived from their use, must be disposed of in accordance with local requirements and guidance from the local waste regulation authority.

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

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