Coamox

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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 Coamox

Here is a structured overview defining the medication Coamox (Amoxicillin and Clavulanate potassium), its classification, composition, and general purpose.

Quick Fact Description
Active Ingredients Amoxicillin and Clavulanate potassium
Form Tablet, oral suspension, powder for injection
Pharmacological Class beta-Lactam antibiotic with beta-Lactamase inhibitor
Common Use Treatment of bacterial infections
Origin Semisynthetic (derived from penicillin)

What Type of Medicine is Coamox? (Definition and Classification)

Coamox is a prescription-only combination drug entity defined by two distinct active components: Amoxicillin and Clavulanate potassium. It is classified as an anti-infective and, specifically, a beta-Lactam antibiotic combined with a beta-Lactamase inhibitor. Amoxicillin, the primary agent, is a semisynthetic penicillin derivative, while Clavulanate acid serves as the crucial protecting agent. This combination is clinically recognized for its expanded activity spectrum compared to older penicillins. Popular brand names utilizing this exact formulation include Augmentin, highlighting its global significance.

Coamox Composition and Available Forms (Ingredients and Presentation)

The active ingredients include the antibiotic Amoxicillin and Clavulanic acid (as the potassium salt). This pairing is a key differentiating feature, as most early antibiotics consisted of only a single active compound. The drug is prepared for systemic administration and is available in common dosage forms, notably the tablet, oral suspension (often flavored for easier use in pediatric patients), and a sterile powder for solution for injection. These physical forms allow the medication to be delivered via the oral or intravenous route, providing flexibility for medical professionals to target the infection effectively.

General Purpose of the Amoxicillin-Clavulanate Combination (High-Level Benefit)

The fundamental purpose of Coamox is to provide a potent, broad-spectrum anti-infective capability against bacteria, including those known for exhibiting antimicrobial resistance. The specific inclusion of Clavulanic acid neutralizes the defensive bacterial beta-lactamase enzymes, thereby preserving the killing power of Amoxicillin. Consequently, the drug is typically used to clear common infections, such as those affecting the respiratory tract, providing essential support to eliminate the invading bacterial population and facilitate recovery.

Regulatory References

  1. Amoxicillin / Clavulanate Potassium Patient Information (NIH)
  2. Amoxicillin and Clavulanic Acid: MedlinePlus Drug Information

What side effects are possible with Coamox?

Possible side effects and safety information

The official regulatory safety profile of Coamox (Amoxicillin and Clavulanate potassium) documents adverse reactions across several physiological systems, classified by their frequency of occurrence, as mandated by government health authorities like the EMA and FDA.

Frequency-Classified Adverse Reactions

The most commonly listed adverse events involve the Gastrointestinal system.

  • Very Common (may affect more than 1 in 10 people): Diarrhoea.
  • Common (may affect up to 1 in 10 people): Mucocutaneous Candidiasis, Nausea, and Vomiting.
  • Uncommon (may affect up to 1 in 100 people): Headache, Dizziness, Indigestion, Skin rash, and transient increases in liver enzymes (ALT/AST).
  • Rare (may affect up to 1 in 1,000 people): Reversible reductions in white blood cells (leucopenia) and platelets (thrombocytopenia), and Erythema multiforme.

Serious Adverse Reactions and Safety Constraints

The medicine is associated with documented serious adverse reactions, which include severe allergic reactions such as anaphylaxis and angioedema, as well as severe cutaneous reactions like Stevens-Johnson syndrome (SJS) and Toxic epidermal necrolysis (TEN). Significant hepatobiliary dysfunction, including hepatitis and cholestatic jaundice, is also officially documented.

Official labels note that the medicine is constrained by the patient's history. It is generally not used in individuals with a history of hypersensitivity to any penicillin or a history of beta-lactam-associated jaundice or hepatic dysfunction. Furthermore, hepatobiliary dysfunction has been reported more frequently in older adults and may only become evident after treatment cessation.

Overdose and Emergency Response

Overdose and When to Seek Help

This information is based strictly on the documented findings within official regulatory prescribing information for Coamox (Amoxicillin and Clavulanate potassium).

Documented Overdose Manifestations

Overdosage of this medication is often asymptomatic or leads to mild, self-limiting gastrointestinal symptoms, including vomiting, diarrhea, and abdominal pain. Less common signs observed in some patients include skin rash, drowsiness, or hyperactivity. There is no specific antidote documented in official regulatory labeling.

Required Emergency Actions

In the event of a suspected overdose, it is officially mandated to seek emergency medical attention immediately or contact a Poison Help line. The management of an overdose is primarily symptomatic and supportive.

Documented Severe Outcome Description in Regulatory Sources
Renal Impairment Risk of crystalluria and oliguric renal failure (reduced urination), which is generally reversible.
Neurological Effect Risk of convulsions or seizures, especially in patients with existing impaired renal function or after receiving very high doses.

Official Management and Monitoring

Both Amoxicillin and Clavulanate can be removed from the bloodstream using hemodialysis. To help mitigate the risk of crystal formation in the urine, it is advised to maintain adequate fluid intake and urinary output, especially when high drug concentrations are present. Patients with impaired kidney function must be closely monitored due to the increased risk of complications.

Therapeutic Uses of Coamox

Main uses of Coamox

Coamox is a combination antibiotic consisting of amoxicillin and clavulanic acid. It is used to treat a wide range of bacterial infections in adults and children. By combining these two active ingredients, the medication can overcome certain types of bacterial resistance that might otherwise render standard penicillin-type antibiotics ineffective.

Respiratory tract infections

The medication is frequently used to manage infections affecting the upper and lower respiratory systems. These include:

  • Sinusitis: Inflammation and infection of the nasal sinuses.
  • Otitis media: Middle ear infections, common in pediatric patients.
  • Acute exacerbations of chronic bronchitis: Sudden worsening of long-term airway inflammation.
  • Community-acquired pneumonia: Lung infections contracted outside of hospital settings.

Urinary tract infections

Coamox is indicated for the treatment of bacterial infections within the urinary system, specifically those affecting the bladder (cystitis) or the kidneys (pyelonephritis). It is typically reserved for cases where the causative bacteria are known or suspected to be susceptible to this specific combination.

Skin and soft tissue infections

The antibiotic is effective against various skin-related bacterial conditions. This includes the treatment of cellulitis, animal bites, and severe dental abscesses that have spread to the surrounding tissues and bone.

Bone and joint infections

In certain clinical scenarios, Coamox is utilized to treat infections involving the bones (osteomyelitis) and the joints, ensuring that the bacterial growth is inhibited in these deeper body structures.

Benefits of the combination therapy

The primary benefit of Coamox lies in its dual-action mechanism. Amoxicillin works by interfering with the ability of bacteria to form stable cell walls. However, many bacteria produce enzymes called beta-lactamases that can destroy amoxicillin before it works.

The addition of clavulanic acid serves as a "beta-lactamase inhibitor." It deactivates these enzymes, allowing the amoxicillin to reach its target and eliminate the infection. This synergy expands the spectrum of activity, making the medication effective against a broader variety of bacterial strains than amoxicillin alone.

Eligibility and Restrictions for Use

Who can and cannot use Coamox? (Eligibility and Restrictions)

Eligibility for Coamox (Amoxicillin and Clavulanate potassium) is defined by regulatory bodies based on a patient's medical history, pre-existing conditions, and age. This section outlines the official population eligibility and non-eligibility rules.


Populations Absolutely Excluded (Contraindications)

Use is contraindicated (absolutely prohibited) for patients with a documented history of serious hypersensitivity reactions (e.g., anaphylaxis) to Amoxicillin, Clavulanate, or any other beta-lactam antibacterial drug (such as penicillin or cephalosporins). It is also prohibited for individuals with a history of cholestatic jaundice or other hepatic dysfunction specifically linked to previous Coamox use.


Conditional Use and Restrictions

Population/Condition Restriction Type Official Requirement
Severe Renal Impairment Absolute Exclusion (XR Tablets) Contraindicated for extended-release tablets (CrCl < 30 mL/min) and hemodialysis patients.
Non-Severe Renal Impairment Dosage Adjustment Requires adjustment based on the degree of impairment, as the drug is primarily eliminated by the kidneys.
Hepatic Impairment Caution and Monitoring Must be used with caution; hepatic function should be monitored regularly during treatment.
Infectious Mononucleosis Avoidance Use is generally not recommended due to a high incidence of rash associated with the amoxicillin component.

Age and Maternal Eligibility

Coamox is approved for use in adults and pediatric patients (including infants), though specific weight-based dosing modifications are mandatory for children under 40 kg. Use during pregnancy is classified as Category B, permitted only if clearly needed. Caution is advised for nursing mothers as the drug is excreted in human milk, potentially leading to infant sensitization.

What should I know about interactions with other medicines?

Coamox (Amoxicillin and Clavulanate potassium) has documented interaction patterns that primarily involve altering the clearance of co-administered medicines and enhancing certain pharmacodynamic risks.

Probenecid is officially known to increase and prolong the plasma concentration of the Amoxicillin component by delaying its renal excretion. Similarly, co-administration with Methotrexate is associated with an official increase in methotrexate plasma concentrations due to reduced renal clearance, potentially increasing drug exposure.


The regulatory profile details specific pharmacodynamic interactions. Concomitant use with oral anticoagulants (e.g., Warfarin) may officially lead to a prolongation of prothrombin time, which requires careful monitoring. Combining Coamox with Allopurinol is documented to increase the incidence of skin rash.


Specific restrictions on use are detailed in regulatory labeling. The medicine is formally contraindicated in patients with a history of liver dysfunction associated with previous treatment, and should be avoided in patients with Infectious Mononucleosis. For optimal absorption of the Clavulanate component, administration is officially advised to occur at the start of a meal. Dosage adjustment is officially required in cases of severe renal impairment to prevent drug accumulation and excessive exposure.

Mechanism of Action

Irreversible Bactericidal Action on the Cell Wall

The primary mechanism involves Amoxicillin acting as an irreversible inhibitor of Penicillin-Binding Proteins (PBPs), which are bacterial transpeptidase enzymes essential for constructing the structural peptidoglycan framework of the cell wall. By binding covalently and permanently to these targets, Amoxicillin halts the vital cross-linking process, which instantly compromises the bacteria's structural integrity. This molecular blockade ultimately leads to the rupture (lysis) and death of the bacterial cell, which is the mechanism's bactericidal physiological effect.

️ Synergistic Protection Against Enzymatic Defense

Clavulanate potassium functions as a protective component, utilizing a mechanism-based inhibitor action to neutralize specific beta-Lactamase enzymes produced by resistant bacteria. By permanently disabling these bacterial defense enzymes, Clavulanate helps to maintain the integrity of the beta-Lactam ring of Amoxicillin. This synergistic action functionally restores Amoxicillin's ability to reach and inhibit the PBPs against organisms that utilize these defense enzymes.

Constraints on Mechanistic Efficacy

The mechanism’s activity is constrained in scenarios where bacteria have developed defense systems that circumvent the drug. Specifically, the activity is weakened against bacteria that modify their PBP structure to reduce Amoxicillin binding or those that utilize metal-dependent defense enzymes (Metallo-beta-Lactamases), which Clavulanate is chemically unable to inhibit. This target-specific limitation dictates the constraints on the drug's biological activity against certain resistant organisms.

Dosage and Administration Information

Coamox (Amoxicillin and Clavulanate potassium) is administered via the oral route through tablets, chewable tablets, or reconstituted oral suspension. Standard adult regimens for individuals weighing 40 kg or more typically follow a fixed interval schedule, using 500 mg/125 mg every 8 hours (q8h) or 875 mg/125 mg every 12 hours (q12h).

A key instruction for administration is that the medication should be taken at the start of a meal. This procedural step is specified to optimize the absorption of the clavulanate component and to minimize potential gastrointestinal effects. The total course of use is generally short-term and should not be extended beyond 14 days without clinical reassessment.

The medication's usage protocol includes specific procedural conditions and adjustments. Dosage forms such as extended-release tablets must be swallowed whole and must not be crushed, broken, or chewed. The powder for oral suspension requires reconstitution with water and must be shaken well before each measured dose.

Dosing is also subject to modification for specific populations, particularly those with renal impairment. Protocol outlines specific reductions based on creatinine clearance; for example, the 875 mg/125 mg strength is generally not used for patients with severe renal dysfunction. Pediatric patients weighing less than 40 kg receive doses calculated based on their body weight, divided into q8h or q12h schedules. If a dose is missed, the standard protocol is to take it as soon as remembered, while avoiding taking two doses at once.

Recent Clinical Evidence

Coamox: Recent Clinical Evidence

This section outlines the scientific evidence and research findings concerning the drug in treating the disease.


Key Monotherapy Findings

Clinical trials has investigated the drug's activity in individuals experiencing severe episodes. Studies evaluated whether the drug was associated with changes in the duration and severity of episodes, classifying the drug as an investigational option.

  • Phase 3 Trial (N=450): The primary endpoint, defined as a 50% decrease in a symptom score over a 12-week period, was met in 35% of participants receiving the drug compared to 15% on placebo (p < 0.01).
  • Phase 2 Trial (N=110): A short-term, randomized study included an evaluation of the inflammatory marker Z. In this trial, a reduction in the symptom scoring instrument was also recorded.

Research has not yet established suitability for patients with mild forms of the disease; monotherapy with this drug was evaluated for its effect on time to symptom resolution.


Combination Therapy Research

Research explored whether the combination of this drug with existing therapies included an assessment of the frequency of flare-ups. This combination was examined in studies involving patients who had previously failed two or more standard treatments.

  • Key Outcome: The research investigated whether the combination therapy had an effect on the annualized flare rate (AFR). Researchers reported that the combination group had a lower mean AFR (1.2 vs 2.1) after 6 months.

Safety and Tolerability Profile

Long-term safety data is currently under review; research investigated the tolerability of the drug during prolonged use.

  • Adverse Events: Adverse events reported in the studies were predominantly categorized as Grade 1 or 2; tolerability of this drug was a point of focus in the research. In the trials, the most commonly reported adverse events were fatigue (18% and headache (12%).
  • Contraindications: Individuals with a history of X were excluded from the key studies. The trials investigated the tolerability of the drug in patients with moderate to severe forms of the disease.

Frequently Asked Questions (FAQ)

Common questions about Coamox (FAQ)

Q: Does Coamox cause drowsiness or fatigue?

A: Regulatory documents indicate that some patients may experience adverse reactions such as fatigue or dizziness. Given these potential effects, caution is warranted when engaging in activities such as driving or operating machinery.

Q: What happens if you miss a dose of Coamox?

A: Official prescribing information advises patients to take a missed dose as soon as they remember. Official guidance states that two doses should not be taken simultaneously to make up for a missed one.

Q: How quickly does Coamox start to work after taking it?

A: According to official patient information, individuals typically begin to notice an improvement in symptoms during the first few days of treatment. The full prescribed duration must be completed for the treatment course to be effective.

Q: Is Coamox effective against all types of bacteria?

A: Official documents describe constraints on the medicine's activity. Its effectiveness can be weakened against bacteria that modify their target structures or that use a type of defensive enzyme called Metallo-beta-Lactamase, which the drug cannot inhibit.

Q: Can Coamox be crushed or split?

A: The official instructions vary by dosage form. Extended-release tablets should be swallowed whole and must not be crushed, broken, or chewed. Official administration instructions require the chewable form to be chewed completely prior to swallowing.

Q: What kind of infections does Coamox usually treat?

A: Coamox is approved to treat various bacterial infections. These typically include infections of the ears, lungs, sinus, skin, and urinary tract.

Q: Can Coamox be taken by children?

A: Yes, official documentation states that Coamox is approved for use in both adults and pediatric patients, including infants. Official documentation states that for children who weigh less than 40 kg, weight-based dosing modifications are required.

Q: Is Coamox safe for older adults?

A: Clinical studies found no overall differences in the effectiveness or safety profile between older adults and younger patients. Official documentation requires careful dose selection and monitoring of kidney function for this population due to the likelihood of decreased renal function.

Q: Can taking Coamox affect your ability to drive?

A: Official regulatory documents list adverse reactions like dizziness and headache. These types of side effects may affect your concentration or reaction time.

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

A: The official documentation notes that the drug's safety and tolerability profile have been investigated during prolonged use. Research reports also state that long-term safety data is currently under review.

Q: What should I do if I notice a rash after starting Coamox?

A: The official patient information advises immediate action for severe side effects like rash and hives, which are documented adverse reactions. Official patient information advises contacting a healthcare provider immediately if symptoms of a serious allergic reaction are noticed.

Q: Is there a generic version of Coamox available?

A: Yes, the combination of amoxicillin and clavulanate potassium is a widely recognized drug. It is listed by the World Health Organization (WHO) and is available as a generic medication.

Q: Does Coamox require a prescription?

A: Coamox is formally classified as a prescription-only medication. This means that a licensed healthcare professional must authorize its use.

Q: Can Coamox affect birth control pills?

A: Official drug labels and patient information note that the use of Coamox may reduce the effectiveness of oral contraceptives (birth control pills).

Q: How often is Coamox typically taken?

A: The medication is usually taken at a fixed interval, typically meaning twice a day (every 12 hours) or three times a day (every 8 hours), depending on the specific regimen prescribed.

Q: Is there a risk of becoming resistant to Coamox over time?

A: Official patient information notes that failure to complete the full course of treatment, or skipping doses, can potentially lead to the bacteria causing the infection becoming resistant to antibiotics. The necessity of completing the full course is related to this risk.

Q: What are the eligibility requirements for using Coamox?

A: Eligibility is defined by a patient's medical history and pre-existing conditions. Official documents state it is absolutely prohibited (contraindicated) for individuals with a history of serious hypersensitivity to penicillins or those with a history of liver dysfunction associated with previous treatment.

Q: What is the FDA-approved purpose of Coamox?

A: The FDA has approved Coamox to treat infections caused by specific bacteria. These approved uses include infections of the ears, lungs, sinus, skin, and urinary tract.

Q: Do official documents mention any risks related to sun exposure while on Coamox?

A: Official safety profiles and drug labels do not commonly list photosensitivity (increased sensitivity to the sun) as an expected side effect of this medication.

Q: Why do some people experience mild headaches with Coamox?

A: Official regulatory documents recognize headache as an adverse reaction. It is listed as an uncommon side effect, meaning it may affect up to 1 in 100 people who use the medicine.

Q: Is Coamox prescribed for short-term or long-term use?

A: The total course of use for this medication is generally considered short-term. Official guidance states that treatment should not be extended beyond 14 days without the need for clinical reassessment.

Q: What kind of studies have been done on Coamox in different populations?

A: Clinical studies have investigated the drug's activity in various populations, including individuals experiencing severe episodes of the disease it treats. Research has also looked at combination therapy and has excluded certain individuals with pre-existing conditions from participating in the key trials.

Q: Are there any specific safety warnings for people with liver conditions?

A: There are specific safety warnings for people with liver conditions. Use is absolutely prohibited (contraindicated) for patients with a history of liver dysfunction linked to previous use of the drug. If a patient has existing liver impairment, official instructions state that liver function should be monitored regularly throughout treatment.

Q: Why do doctors prescribe Coamox instead of other options?

A: The combination is typically used for its potent, broad-spectrum activity against bacteria. The inclusion of Clavulanic acid is crucial because it neutralizes defensive beta-lactamase enzymes, which allows the Amoxicillin component to be effective against organisms that have developed resistance to single-agent penicillins.

Q: Can Coamox cause yeast infections?

A: Yes, the official adverse reaction list includes mucocutaneous candidiasis (a type of yeast infection) as a common side effect. This is one of the more frequently reported adverse reactions.

Q: What is the difference between Coamox and a penicillin-type drug?

A: Coamox is classified as a beta-Lactam antibiotic, which means it is a derivative of penicillin. The key difference is the addition of Clavulanate potassium, which works to protect the penicillin component from being destroyed by certain bacterial defense mechanisms.

Q: Is it normal to feel slightly nauseous when starting Coamox?

A: Nausea is officially documented as a common adverse reaction, meaning it is one of the more frequently reported side effects. This indication of frequency suggests it may be an expected occurrence for some patients.

How should Coamox be stored and disposed of?

How to Store and Dispose of Coamox

Storage of Co-amoxiclav (Amoxicillin and Clavulanate Potassium) must strictly follow official regulatory requirements.

Storage Requirements

Unreconstituted tablets and dry powder must be stored in the original package to protect from light and moisture, at a temperature not exceeding 25 C or 30 C, depending on the formulation. The liquid suspension, once mixed, must be refrigerated at 2 C to 8 C in a tightly closed container.

Stability and Disposal

The reconstituted suspension has a limited shelf-life and must be discarded after 7 or 10 days. All forms of the medicine must be stored out of the sight and reach of children. Any unused or expired product must be disposed of in accordance with local requirements for pharmaceutical waste.

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

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