AMPICLOX® 500 mg Capsules — Verified and Updated Drug Information
Scope: This profile is focused on Ampiclox 500 mg hard capsules marketed in Egypt, containing ampicillin 250 mg + cloxacillin 250 mg per capsule. The most recent GSK product-information document I could locate that is directly identifiable for Ampiclox is Version GA03, dated 25 August 2014; a 2023 regulatory SmPC for another Ampicillin/Cloxacillin product reproduces the same core Ampiclox information. Egyptian medicine databases continue to list Ampiclox 500 mg/12 capsules and identify Medical Union Pharmaceuticals (MUP) in Egypt with the product.
1. Disclaimer
This information is provided for educational and reference purposes and is not a substitute for the prescribing information supplied with the medicine, professional medical judgment, diagnosis, or individualized treatment advice. Antibiotic selection and dosing should take into account the suspected or confirmed organism, site and severity of infection, antimicrobial susceptibility, allergy history, renal/hepatic function, age, and other relevant clinical factors.
We do not guarantee the accuracy, currency or completeness of information regarding medications or medical products, and official sources should be verified before making any decisions. Readers are responsible for independently verifying the information before relying on it.
Because regulatory status, manufacturers, formulations, availability, and labeling may differ between countries and may change over time, the package and current Egyptian Drug Authority (EDA) information should be checked for the exact product available in Egypt. The EDA itself states that its Egyptian Pharmaceutical Information Center provides updated, evidence-based pharmaceutical information.
2. Summary
Ampiclox 500 mg capsules are an oral fixed-dose combination of two penicillin antibiotics: ampicillin and cloxacillin, with 250 mg of each active ingredient per capsule. The combination pairs the broader activity of the aminopenicillin ampicillin with the antistaphylococcal, penicillinase-resistant activity of cloxacillin. Both agents are bactericidal and inhibit bacterial cell-wall synthesis.
The product information describes Ampiclox as being used for susceptible bacterial infections, including selected respiratory, postoperative, ENT, obstetric, bloodstream, bone, and other infections. Importantly, activity against individual bacteria cannot be assumed solely from the name of the infection: resistance is geographically variable and can be high, and the product information specifically recommends culture and susceptibility testing when appropriate.
Ampiclox is not an appropriate treatment for viral infections such as ordinary colds or influenza. Unnecessary antibiotic use contributes to adverse effects and antimicrobial resistance.
3. Brand Name
Ampiclox® 500 mg Capsules
The product is a GlaxoSmithKline-associated trademark internationally. The GSK product information states that AMPICLOX is a trademark of the GlaxoSmithKline group of companies.
For the Egyptian market, medicine databases currently identify AMPICLOX capsule, hard 250 mg + 250 mg under Medical Union Pharmaceuticals Egypt (MUP). Historical Egyptian registration information identifies Medical Union Pharmaceuticals in Egypt together with SmithKline Beecham UK as the foreign principal associated with the product.
4. Category
Pharmacological class: Penicillin antibacterial combination.
More specifically, Ampiclox combines:
Ampicillin: an aminopenicillin / broad-spectrum penicillin.
Cloxacillin: an isoxazolyl, antistaphylococcal penicillin that is resistant to staphylococcal penicillinases.
The WHO ATC system currently places ampicillin combinations in J01CR, “combinations of penicillins, including beta-lactamase inhibitors”; J01CR01 is named “ampicillin and beta-lactamase inhibitor.” However, this ATC terminology should not be interpreted as meaning that cloxacillin itself is a conventional beta-lactamase inhibitor such as sulbactam or clavulanate. Cloxacillin works principally by being resistant to staphylococcal beta-lactamase rather than by acting as a separate beta-lactamase inhibitor.
5. Active Ingredient
Each Ampiclox 500 mg capsule contains:
- Ampicillin 250 mg, as ampicillin trihydrate.
- Cloxacillin 250 mg, as cloxacillin sodium.
Therefore, the stated 500 mg strength represents the combined nominal amount of the two active antibacterial components: 250 mg + 250 mg, rather than 500 mg of either component individually.
6. Pharmaceutical Form & Strength
Dosage form: Hard gelatin capsule.
Strength: 500 mg total active ingredients per capsule:
Ampicillin 250 mg + Cloxacillin 250 mg.
The GSK product information describes the 500 mg presentation as a hard gelatin capsule containing almost white granular powder. The Egyptian market product is listed as Ampiclox 500 mg, 12 capsules.
The current Egyptian listing should not be confused with Ampiclox suspension, neonatal drops, or injectable presentations described in international product information; those formulations have different compositions, indications, administration requirements, and excipients.
7. Manufacturer & Marketing Authorization Holder
For the Egyptian market, available Egyptian medicine databases identify Medical Union Pharmaceuticals (MUP), Egypt as the laboratory/manufacturer associated with Ampiclox, while historical Egyptian registration information associates the product with SmithKline Beecham UK as the foreign principal.
The GSK international product information confirms the Ampiclox trademark relationship with the GlaxoSmithKline group. It also shows that manufacturing arrangements can differ by country; the particular international document located identifies manufacture under licence by Medreich Limited, India, so that manufacturing statement should not be automatically transferred to the Egyptian presentation.
Current Egyptian marketing-authorization-holder status: I could not locate a publicly searchable, current EDA record that unambiguously states the present Egyptian MAH for the exact 500 mg/12-capsule presentation. Accordingly, it would be inaccurate to invent or state a definitive current MAH beyond the manufacturer/registration information that can actually be supported.
8. Mechanism of Action
Ampiclox contains two bactericidal beta-lactam antibiotics.
Ampicillin binds to bacterial penicillin-binding proteins (PBPs) and interferes with the transpeptidation steps required for peptidoglycan cross-linking. This weakens the bacterial cell wall and can lead to bacterial cell death.
Cloxacillin acts by the same fundamental beta-lactam mechanism but is structurally resistant to the beta-lactamases produced by susceptible staphylococci. Consequently, it can retain activity against many methicillin-susceptible staphylococci (MSSA/MSCoNS) that would be resistant to ordinary penicillin.
The combination therefore attempts to cover susceptible organisms for which ampicillin alone would be inadequate because of staphylococcal penicillinase, while retaining ampicillin's broader activity against selected organisms. It does not overcome all mechanisms of beta-lactam resistance.
9. Spectrum of Activity
Ampiclox has activity against selected Gram-positive and Gram-negative bacteria, but its actual clinical spectrum is constrained by antimicrobial resistance.
The product information specifically states that:
- MSSA and methicillin-susceptible coagulase-negative staphylococci (MSCoNS) are commonly susceptible.
- MRSA and methicillin-resistant coagulase-negative staphylococci (MRCoNS) are resistant.
- For other indicated organisms, activity is broadly similar to that of ampicillin and includes only limited activity against Gram-negative organisms.
- Acquired resistance varies geographically and may be high.
The product information lists susceptible organisms in its broader pharmacological description, including Staphylococcus aureus, Streptococcus pyogenes, viridans streptococci, Streptococcus pneumoniae, Neisseria species, Haemophilus influenzae, Escherichia coli, Salmonella typhi, and Proteus mirabilis. However, these should not be interpreted as a guarantee of susceptibility for a current clinical isolate; local resistance patterns and susceptibility testing remain important.
The combination should therefore not be described simply as a universally “broad-spectrum antibiotic.” Its usefulness depends on the susceptibility of the causative organism.
10. Pharmacokinetics
Absorption
Both ampicillin and cloxacillin are acid-stable and are absorbed orally. The GSK information reports approximate oral absorption of 40% for ampicillin and 50% for cloxacillin. Food may reduce absorption, which is why Ampiclox is recommended 0.5–1 hour before meals.
Distribution
Ampiclox distributes into a variety of tissues and body fluids, including bronchial secretions, sinuses, saliva, bile, serous membranes, and middle-ear fluid. Penetration into cerebrospinal fluid is limited when the meninges are not inflamed. Small quantities are excreted into breast milk.
Half-life
The reported plasma half-lives are approximately:
- Cloxacillin: 0.5–1 hour.
- Ampicillin: 1–1.5 hours.
Protein binding
Approximate serum protein binding is:
- Cloxacillin: 94%.
- Ampicillin: 18%.
Metabolism and elimination
The product information reports partial metabolism, with approximately 20% of cloxacillin and 40% of ampicillin metabolised in normal subjects. Elimination is mainly renal. Approximately 30% of an oral dose is reported to be recovered in active form in urine for Ampiclox overall, with greater urinary recovery after parenteral administration; approximately 10% of the administered dose is excreted in bile.
Because renal elimination is important, dosing requires adjustment in renal impairment according to the product information.
11. Indications
The product information supports use for treatment of susceptible bacterial infections, including selected:
- Post-operative wound infections.
- Post-operative pulmonary infections.
- Bronchopneumonia.
- Acute exacerbations of chronic bronchitis.
- Puerperal fever.
- Septicaemia.
- Bone infections such as osteomyelitis.
- Ear, nose and throat infections.
- Other mixed infections involving susceptible Gram-positive and Gram-negative organisms.
The manufacturer information specifically recommends culture and antimicrobial susceptibility testing when appropriate, especially when resistance makes the usefulness of Ampiclox questionable.
Ampiclox should not be used simply because a patient has cough, sore throat, cold symptoms, influenza, or another illness caused by viruses. Antibiotics do not treat viral infections.
12. Administration
Oral administration
Ampiclox should be taken 0.5–1 hour before meals because food can reduce oral absorption.
The GSK product information gives the following label-based oral dosage for adults and older adults:
Adults and elderly: 1–2 g every 6 hours.
With the 500 mg capsule presentation, that corresponds mathematically to 2–4 capsules per dose, but this is label information, not a recommendation for self-treatment. The appropriate dose and duration must be determined by the prescriber according to the infection and patient-specific factors.
The product information also describes reduced-frequency dosing for renal impairment, including an initial normal dose followed by reduced maintenance frequency depending on creatinine clearance. Patients undergoing dialysis may require an additional dose after the procedure.
Important practical point
The older practice of automatically using a fixed “7–10 day” course for every infection should not be presented as a universal rule. Antibiotic duration should be based on the infection being treated and the prescriber’s current treatment plan.
13. Method of Preparation
For Ampiclox 500 mg capsules, no preparation or reconstitution is required. The capsule is supplied as a finished oral dosage form and should be swallowed according to the prescribed regimen.
The reconstitution instructions sometimes reproduced under the name “Ampiclox”—such as adding water to neonatal drops or suspension—apply to different pharmaceutical presentations, not to the 500 mg hard capsule. The current GSK information separately describes these preparations.
Capsules should not be opened, crushed, mixed into liquids, or otherwise altered unless a pharmacist or prescriber specifically instructs the patient to do so.
14. Contraindications
Ampiclox should not be administered to patients with a history of hypersensitivity to beta-lactam antibiotics, including penicillins and relevant cephalosporins, or to any component of the specific formulation.
A history of severe immediate penicillin allergy, including anaphylaxis, is particularly important because serious and occasionally fatal hypersensitivity reactions have been reported with beta-lactam antibiotics.
The product information also states that Ampiclox is contraindicated for ocular administration. This is relevant to injectable formulations and should not be interpreted as a route of administration for the capsule.
15. Warnings & Precautions
Hypersensitivity and anaphylaxis
Previous beta-lactam allergy should be established before treatment. Serious hypersensitivity reactions, including anaphylaxis, can occur with oral as well as parenteral therapy. If a significant allergic reaction occurs, treatment should be discontinued and appropriate medical management instituted.
Infectious mononucleosis and lymphoid leukaemia
Ampicillin-containing medicines are associated with a high frequency of rash in patients with infectious mononucleosis and in certain patients with acute or chronic lymphoid leukaemia. Ampiclox should therefore be avoided when these conditions are suspected.
Antibiotic-associated diarrhoea and colitis
Persistent or significant diarrhoea during or after antibiotic therapy may represent antibiotic-associated colitis, including potentially severe Clostridioides difficile-associated disease. The product information specifically advises investigation and discontinuation of treatment where clinically appropriate.
Renal impairment
Dosage adjustment is required in renal impairment because the components are substantially eliminated through the kidneys.
Prolonged or inappropriate therapy
Prolonged use can permit overgrowth of nonsusceptible organisms and can contribute to antimicrobial resistance. Antibiotics should therefore be used only when indicated and according to the prescribed regimen.
Resistance
The existence of the combination does not guarantee activity against resistant bacteria. In particular, MRSA and MRCoNS are resistant according to the product information. Local resistance patterns may substantially influence whether Ampiclox is appropriate.
16. Drug Interactions
The product information identifies several interactions or potential interactions:
Probenecid: decreases renal tubular excretion of Ampiclox and can therefore increase and prolong its blood concentrations.
Allopurinol: concurrent use has been associated with an increased likelihood of allergic skin reactions.
Sulfonamides and acetylsalicylic acid: the product information reports inhibition of cloxacillin protein binding in vitro, potentially increasing free cloxacillin concentrations; the clinical significance of this finding is less certain.
Bacteriostatic antibiotics: the product information states that bacteriostatic drugs may interfere with the bactericidal action of Ampiclox; the clinical relevance depends on the specific drug and infection.
Important correction concerning oral contraceptives
Older Ampiclox labeling states that antibiotics may reduce the efficacy of combined oral contraceptives through effects on gut flora. This is too broad by current evidence-based standards. Current CDC contraceptive guidance states that most broad-spectrum antibiotics do not reduce the effectiveness of combined hormonal contraceptives; the clinically important exception is enzyme-inducing therapy such as rifampin or rifabutin.
Therefore, Ampiclox should not be described as routinely making combined oral contraceptives ineffective. However, vomiting, severe diarrhoea, or use of other interacting medicines can create separate contraceptive concerns.
Patients should tell the prescriber/pharmacist about prescription medicines, non-prescription medicines, and supplements before starting treatment.
17. Side Effects
The reported adverse-effect profile includes the following:
Common
- Diarrhoea
- Nausea
- Skin rash
- Urticaria
- Pruritus
Uncommon
- Vomiting
Very rare or serious reported reactions
- Anaphylaxis and other severe hypersensitivity reactions.
- Haemolytic anaemia.
- Leucopenia.
- Thrombocytopenia.
- Agranulocytosis.
- Myoclonus and convulsions.
- Pseudomembranous colitis and haemorrhagic colitis.
- Hepatitis and cholestatic jaundice.
- Transient increases in transaminases.
- Severe bullous skin reactions, including erythema multiforme, Stevens–Johnson syndrome, and toxic epidermal necrolysis.
- Exfoliative dermatitis.
- Purpura.
- Interstitial nephritis.
The source notes that the adverse-reaction information reflects the individual components and/or the combination and that many reactions are not unique to Ampiclox. The very-rare categories were based on extensive post-marketing reporting and therefore should not be interpreted as precise incidence measurements.
A severe allergic reaction, breathing difficulty, facial or throat swelling, extensive blistering/peeling rash, severe persistent diarrhoea, jaundice, or other serious reaction requires prompt medical evaluation.
18. Use in Special Populations
Pregnancy
The Ampiclox product information states that adequate human pregnancy data were not available in the referenced labeling, while animal studies did not identify a risk to pregnancy or embryo-fetal development. Ampiclox should therefore be used during pregnancy only when clinically indicated and when the prescriber considers the expected benefits to outweigh the potential risks.
Breastfeeding
The product information states that small quantities of Ampiclox are excreted into breast milk and that adequate human and animal lactation data were not available in that labeling. Breastfeeding use should therefore be assessed by a healthcare professional for the individual clinical situation.
Children
Paediatric doses are formulation- and age-specific in the product information. Neonatal drops, suspension, and injectable forms have different concentrations and are not interchangeable by volume with the 500 mg capsule.
Elderly patients
The product information includes the elderly under adult dosing but renal function is particularly relevant because renal elimination is important; dosing should therefore be individualized where renal impairment is present.
Renal impairment
Dose reduction or extended dosing intervals may be required according to creatinine clearance. The product information specifies progressively reduced maintenance frequency with declining renal function.
Hepatic impairment
The referenced product information advises reducing the frequency of administration depending on severity.
Driving and operating machinery
The product information reports no observed adverse effect on the ability to drive or operate machinery.
19. Storage Conditions
For Ampiclox 500 mg capsules, the GSK product information specifies:
Store in a dry place below 25°C.
The medicine should be kept in its original packaging where appropriate, protected from unsuitable environmental conditions, and kept out of the reach of children. It should not be used after the expiry date stated on the packaging.
The special refrigeration and post-reconstitution discard instructions sometimes associated with Ampiclox apply to the liquid/neonatal formulations, not to the 500 mg capsules.
20. Additional Sections
Active ingredients and excipients
The GSK product information lists magnesium stearate and colloidal anhydrous silica as excipients for the 500 mg capsule presentation.
This corrects the older formulation wording in which only magnesium stearate was listed for the capsule. The newer located GSK product information should therefore be preferred when describing the formulation.
Overdose
Excessive oral dosing is generally less likely to cause serious toxicity in a person with normal renal function, but very high beta-lactam exposure—particularly in renal failure—can produce neurological toxicity, including convulsions. Gastrointestinal symptoms such as nausea, vomiting, and diarrhoea can also occur. Suspected significant overdose requires medical assessment rather than self-management.
Antimicrobial stewardship
Ampiclox should be reserved for infections for which its spectrum is appropriate. It should not be used merely because symptoms are compatible with an infection. Antibiotics do not treat viral illnesses, and unnecessary use contributes to adverse effects and antimicrobial resistance.
Current Egyptian-market identification
The currently indexed Egyptian presentation is Ampiclox 500 mg, 12 capsules, containing ampicillin + cloxacillin, and Egyptian medicine databases identify MUP / Medical Union Pharmaceuticals in association with the product. Online price pages currently display an old recorded price of EGP 8.60, with the underlying price-change date given as 2 December 2022; because that price evidence is clearly stale, it should not be presented as a current 2026 retail price.
21. Frequently Asked Questions (FAQ)
What does one Ampiclox 500 mg capsule contain?
It contains 250 mg ampicillin + 250 mg cloxacillin. The “500 mg” refers to the combined amount of the two active ingredients.
Is Ampiclox the same as ampicillin alone?
No. Ampiclox combines ampicillin with cloxacillin. Cloxacillin adds antistaphylococcal, penicillinase-resistant activity that ampicillin does not possess.
Is cloxacillin a beta-lactamase inhibitor?
Not in the usual pharmacological sense of drugs such as clavulanate or sulbactam. Cloxacillin is a beta-lactamase-resistant antistaphylococcal penicillin. Its resistance to staphylococcal penicillinase is an intrinsic property of the antibiotic. The WHO ATC classification nevertheless places Ampiclox-type combinations within J01CR.
Does Ampiclox treat colds or flu?
No. Colds and influenza are viral illnesses, and antibiotics do not treat viruses. Antibiotics should be used only when a bacterial infection is suspected or confirmed and antibiotic therapy is clinically indicated.
Can Ampiclox be taken with food?
The product information recommends taking Ampiclox 0.5–1 hour before meals because food may reduce its absorption.
Does Ampiclox cover MRSA?
No. The Ampiclox product information specifically states that MRSA and MRCoNS are resistant.
Can Ampiclox cause an allergic reaction?
Yes. Like other penicillins, it can cause hypersensitivity, including potentially life-threatening anaphylaxis. A previous serious beta-lactam allergy is a major contraindication.
Does Ampiclox routinely reduce the effectiveness of birth-control pills?
Current evidence does not support a general interaction between ordinary broad-spectrum antibiotics and combined hormonal contraceptives. The important antibiotic exceptions are enzyme-inducing agents such as rifampin and rifabutin.
Is Ampiclox 500 mg/12 capsules currently listed in Egypt?
Yes. Current online Egyptian medicine databases continue to list Ampiclox 500 mg 12 capsules, with ampicillin + cloxacillin as the active ingredients and MUP/SmithKline Beecham information associated with the product. However, a current publicly searchable EDA record for the exact presentation was not located, so current regulatory details should be confirmed against the package and EDA.
22. References
- GlaxoSmithKline — AMPICLOX International Product Information, Version GA03, 25 August 2014. This is the most recent directly identifiable GSK Ampiclox product-information version located during the verification, and it provides the detailed composition, indications, dosing, warnings, interactions, adverse reactions, pharmacokinetics, excipients, storage, and product status.
GSK AMPICLOX Product Information - NAFDAC Greenbook — Ampiclox 500 Capsule. Provides an independently accessible regulatory product record confirming the 250 mg + 250 mg formulation of ampicillin/cloxacillin and the prescription-only classification for an Ampiclox 500 capsule product.
NAFDAC Greenbook product record - Egyptian Drug Authority (EDA) — Egyptian Pharmaceutical Information Center. The EDA describes its pharmaceutical information service as providing updated, evidence-based information about medicines and pharmaceutical products.
Egyptian Drug Authority pharmaceutical information service - WHO/WHO Collaborating Centre — ATC/DDD Index. Current ATC information places ampicillin combinations in J01CR; J01CR01 is listed as “ampicillin and beta-lactamase inhibitor.”
WHO ATC/DDD Index - CDC — Combined Hormonal Contraceptives, U.S. Medical Eligibility Criteria. Current guidance states that most broad-spectrum antibiotics do not reduce combined hormonal contraceptive effectiveness, whereas rifampin/rifabutin can reduce effectiveness.
CDC contraceptive guidance - CDC — Healthy Habits: Antibiotic Do's and Don'ts / Common Cold. Supports the statements that antibiotics treat certain bacterial infections, do not treat viral infections, and should be taken only when indicated and as prescribed.
CDC Antibiotic Use guidance - Egyptian market references. Current indexed Egyptian medicine databases list Ampiclox 500 mg/12 capsules and associate it with MUP/Medical Union Pharmaceuticals; historical Egyptian registration material associates the product with Medical Union Pharmaceuticals Egypt and SmithKline Beecham UK. These sources are useful for market identification but should not be treated as substitutes for a current EDA regulatory record.