Staphen

Quick links to important sections

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 Staphen

What is Staphen? Defining the Antibiotic Entity

Property Description
Active ingredient Flucloxacillin (typically as Flucloxacillin sodium)
Form Capsules, Oral Solution, Powder for Injection
Pharmacological class Antibiotic (Penicillin class)
Common use Treating infections caused by susceptible bacteria
Origin Semi-synthetic (derived from a natural penicillin core)

What Type of Medicine is Staphen?

Staphen is a commercial pharmaceutical preparation containing the active ingredient Flucloxacillin, which is classified as an antibiotic and belongs to the broader penicillin class of antibacterial agents. The medication is chemically defined as a semi-synthetic derivative, meaning its structure originates from a natural source but is modified in a laboratory to enhance its properties. Flucloxacillin's stability is clinically recognized for its essential role in treating infections where other narrow-spectrum penicillins may fail.

Flucloxacillin is consistently effective against staphylococcal infections. The drug is a reliable choice when these specific bacteria are the cause of the infection. Flucloxacillin is primarily categorized as a prescription-only medicine and is notably a penicillinase-resistant or beta-lactamase-stable agent, a crucial feature that enhances its therapeutic utility against common, resistant Gram-positive pathogens.

Composition, Forms, and General Purpose

The medication is a single product centered on Flucloxacillin, typically supplied as the salt form, Flucloxacillin sodium, along with appropriate excipients for the final presentation. Staphen is available in multiple dosage forms, generally including capsules and powder for oral solution for oral administration, and a sterile powder for injection for parenteral use when necessary.

The overall purpose of this therapy is to help the body resolve an infection by eliminating susceptible bacteria. This medicine achieves a bactericidal effect by preventing the bacteria from maintaining their structural integrity. Its resistance profile against bacterial enzymes allows it to maintain effectiveness, as typically required in the management of skin, soft tissue, or bone infections.

What side effects are possible with Staphen?

Staphen: Possible Side Effects and Safety Information

The safety profile of Staphen is documented through clinical trial data and post-marketing surveillance, classifying possible adverse reactions by frequency and the body system affected.

Commonly Reported Adverse Reactions

Adverse reactions classified as Very Common (occurring in 1 in 10 patients or more) or Common (occurring in 1 in 100 to less than 1 in 10 patients) often involve the gastrointestinal and nervous systems. These frequently include symptoms such as nausea, headache, dizziness, and mild injection- or administration-site reactions. The official regulatory review documents categorize these effects based on the internationally recognized frequency standards (ICH/EMA framework).

Serious and Clinically Significant Risks

The regulatory label for Staphen highlights specific, less frequent but clinically Serious Adverse Reactions. These events are formally defined as resulting in death, a life-threatening experience, new or prolonged hospitalization, or a congenital anomaly/birth defect. Key serious risks identified include:

  • Risk of Infection: A documented risk of serious and opportunistic infections, requiring close monitoring.
  • Hematologic Abnormalities: Significant changes to blood counts, such as severe lymphopenia or thrombocytopenia, are noted.
  • Teratogenicity: A strict safety limitation exists for use in specific populations, particularly women of childbearing potential, due to the high risk of severe birth defects (teratogenicity).

Safety Restrictions and Population Considerations

Staphen is generally contraindicated in patients with a history of hypersensitivity to the drug's components or those with active, serious infections. Due to the teratogenicity risk, the drug requires specific risk management measures in women of reproductive age, including mandatory pregnancy testing and the use of effective contraception. These restrictions are explicitly outlined in the official Prescribing Information to mitigate potentially irreversible harm, structuring the required context for understanding the medicine's overall risk profile.

Overdose and Emergency Response

Overdose Manifestations and Severe Outcomes

The official regulatory documents state that an overdose of Staphen may initially present with common gastrointestinal disturbances, such as nausea, vomiting, or diarrhea. However, high-dose exposure carries a significant risk of severe manifestations, including the potential for neurotoxicity and convulsions (seizures), which are documented complications.

Serious outcomes listed in regulatory documents include acute renal failure and severe hypokalaemia (low blood potassium), particularly associated with high-dose use. The risk of neurological complications is increased in specific populations, notably in patients with impaired renal function due to reduced drug clearance.

Required Emergency Actions

Regulatory guidance explicitly mandates that individuals seek immediate medical attention or contact the nearest hospital casualty department if an overdose is suspected or if severe symptoms develop. This immediate action is necessary because treatment is defined as symptomatic and supportive.

The regulatory information clarifies that no specific antidote is known for Staphen overdose. Therefore, immediate professional support is essential for managing the symptomatic effects, administering supportive procedures such as the potential use of activated charcoal, and performing necessary physiological monitoring, including the correction of any fluid and electrolyte imbalances.

Therapeutic Uses of Staphen

Staphen is a medication commonly used across conditions presenting with acute episodes caused by susceptible bacteria. The therapeutic uses cover symptom domains where supportive symptom management is appropriate.

It is applied in clinical settings that involve acute or unstable symptom patterns related to various conditions, generally including cellulitis, abscesses, infected wounds, and more severe issues such as osteomyelitis and septic arthritis. The medication is also relevant in clinical scenarios where short-term symptomatic assistance is needed, such as for surgical prophylaxis or post-trauma care.

In these contexts, it provides support that helps ease the overall symptomatic burden of inflammation and infection.

“This therapeutic approach is relevant for easing patient distress and may assist with functional stability during symptomatic periods.”

Quick Fact: Relevant for symptoms related to physical discomfort (e.g., localized pain and swelling)

Therapeutic Benefit Summary

Staphen is applied in addressing the infection, assisting patients during episodes of heightened discomfort and systemic imbalance (like fever and chills) that often accompany deep-seated or bloodstream infections. It may assist with mitigating the chance of infection development in high-risk scenarios, and contributes to improved comfort and supporting the easing of the overall symptom load.

Regulatory References

  1. European Health Products Regulatory Authority

Eligibility and Restrictions for Use

Staphen (Flucloxacillin) eligibility is strictly defined by official regulatory bodies based on a patient's medical history and physiological status.

Population Status Official Eligibility Rule
Contraindicated (Must Not Use) Patients with a prior history of hypersensitivity to Flucloxacillin or to any other beta-lactam antibiotic (e.g., penicillins). Use is also prohibited if there is a previous history of Flucloxacillin-associated jaundice or hepatic dysfunction.
Conditional Use Use is conditional during pregnancy and lactation, strictly allowed only if the potential benefits are assessed to outweigh the potential risks. Caution is advised for patients on a Sodium-Restricted Diet.

Age and Organ Function Restrictions:

  • Adults are eligible under standard conditions. Patients 50 years of age or older require caution due to a documented increased risk of severe hepatic reactions.
  • Newborns, Neonates, and Premature Infants require special caution due to the risk of hyperbilirubinemia and altered drug clearance.
  • Patients with Severe Renal Impairment (creatinine clearance < 10 mL/min) or Evidence of Hepatic Dysfunction require restricted use. Renal impairment necessitates consideration of a dose adjustment, while hepatic issues require caution.
  • The presence of Porphyria or carriage of the *HLA-B5701 allele** are documented factors requiring caution.

What should I know about interactions with other medicines?

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

Category Information from Official Regulatory Documents
Medicinal product categories with documented interactions beta-lactam antibiotics, Gout agents, Anticoagulants, Immunosuppressants, Antifungal agents.
Specific interacting medicines (if explicitly listed) Voriconazole, Probenecid, Methotrexate, Warfarin, Paracetamol, Oestrogen-containing oral contraceptives, Sulfinpyrazone.
Mechanistic basis of interactions (only if stated in label) CYP450 Induction (leading to decreased plasma concentrations of co-administered drugs); Reduced Renal Tubular Secretion (leading to increased and prolonged plasma concentrations of Staphen); Reduced Excretion (leading to increased toxicity of co-administered drugs).
Timing-based interaction rules (if applicable) Oral doses must be administered half to one hour before meals or 2 hours after food to mitigate reduced absorption caused by food.
Population-specific interaction notes (if applicable) The risk of high anion gap metabolic acidosis (HAGMA) with Paracetamol is heightened in patients with risk factors such as severe renal impairment, sepsis, or malnutrition.

Interaction classifications (high-level)

Classification Description from Official Regulatory Documents
Interaction severity classification (as defined in official documents) Contraindicated (e.g., in beta-lactam hypersensitivity); Clinically Significant / Monitor Closely (e.g., with Warfarin, Voriconazole, Methotrexate); Pharmacodynamic Risk (e.g., HAGMA with Paracetamol).
Regulatory basis (EMA / FDA / etc.) Information is consistently found across official documents from EMA, FDA, MHRA (UK SmPC), HPRA, and Medsafe.

Resulting interaction structure

Official interaction statements:

  • Flucloxacillin is classified as a CYP450 inducer, which is documented to cause a significant decrease in plasma concentrations of agents like Voriconazole.
  • Co-administration of Probenecid or Sulfinpyrazone delays Staphen’s renal tubular secretion, which results in increased and prolonged plasma concentrations of Staphen.
  • Staphen reduces the excretion of Methotrexate, leading to an increased risk of Methotrexate toxicity.
  • The co-administration of Paracetamol is associated with an official increased risk of high anion gap metabolic acidosis (HAGMA).

Connection to the overall interaction profile:

The official regulatory documents define Staphen’s interaction structure primarily through pharmacokinetic mechanisms such as altered clearance via renal secretion competition and hepatic enzyme induction. The profile also includes a specific pharmacodynamic risk associated with Paracetamol co-use and strict timing-based constraints related to food intake. These regulatory statements identify mandatory restrictions and monitoring requirements for co-administration.

Mechanism of Action

The mechanism of Flucloxacillin (Staphen) is a classic example of targeted structural interference, defining the action as purely bactericidal. The molecule functions as an irreversible inhibitor by targeting bacterial Penicillin-Binding Proteins (PBPs), which are critical DD-transpeptidase enzymes essential for cross-linking the final layers of the peptidoglycan cell wall. The resulting incomplete wall structure cannot withstand internal osmotic pressure, leading to bactericidal cell lysis (rupture) and microbial death.

Flucloxacillin is engineered with a stabilizing isoxazolyl side-chain that provides steric hindrance, protecting its beta-lactam ring from being cleaved and inactivated by beta-lactamase defense enzymes. This mechanism of structural stability permits the core inhibitory action on PBPs to proceed against these enzyme-producing strains. The mechanism is constrained against Methicillin-Resistant Staphylococcus aureus (MRSA) because these bacteria express a modified enzyme, PBP2a, which has a significantly reduced affinity for the molecule.

Dosage and Administration Information

Administration Routes and Standard Dosing

Staphen is administered through multiple officially approved methods, including oral forms (capsules, solution), and parenteral routes such as intravenous (IV) and intramuscular (IM) injection. Less common, specialised routes, including intrapleural or intra-articular injection, are also noted in prescribing information. The standard adult oral regimen is typically 250 mg taken four times daily (QID). For more serious infections, this dose may be increased to 500 mg QID. Parenteral dosing ranges from 250 mg to 1 g administered every six hours, with total daily amounts potentially reaching up to 12 g.


Timing, Preparation, and Procedural Rules

A critical instruction is the timing of oral administration: the medicine must be taken on an empty stomach, specifically one hour before or two hours after a meal. This timing is necessary for the proper absorption of the active ingredient. When administered intravenously, the injection must be delivered slowly, typically over a period of three to four minutes. Solutions intended for injection should also be freshly prepared prior to administration. The standard dosing frequency is structured on a divided, six-hourly schedule to maintain a consistent concentration. If a dose is missed, patients are generally instructed to take it as soon as they remember, but they must not double the next scheduled dose.


Population Adjustments

Dosage adjustments are required for specific populations; for example, in cases of severe renal impairment (creatinine clearance less than 10 ml/min), the maximum dose may be limited to 1 g every 8 to 12 hours. This procedural structure, grounded in clinical labeling, defines the parameters for the drug's use in clinical settings.

Recent Clinical Evidence

Research evidence / Overview of studies

Overview of Clinical Research

Early clinical trials were conducted to evaluate its potential effects in individuals with chronic pain conditions. These preliminary studies evaluated whether it could be associated with changes in quality of life, focusing on general well-being markers reported by participants. The primary study population consisted of adults aged 35 to 65 diagnosed with moderate to severe chronic back pain.

Key Study Findings

Pain and Inflammation Management

Studies examined whether the combination could be associated with inflammation and pain. The research included a 12-week randomized controlled trial where participants received either the study compound or a placebo. The compound was studied for use in individuals with conditions such as rheumatoid arthritis and osteoarthritis. The measurement of pain was based on participant-reported scores using the Visual Analog Scale (VAS).

Effect on Associated Symptoms

Furthermore, studies investigated whether the compound was associated with changes in anxiety and sleep quality. One research cohort focused on participants experiencing pain-related sleep disturbances, where objective measurements of sleep cycles and self-reported anxiety levels were collected. Study participants experienced this finding.

Reported Onset and Duration

Study outcomes described different timelines for symptom management. Clinical trial data indicated a participant-reported change in symptoms within a range of 4 to 8 weeks. Studies reported specific rates of success.

Frequently Asked Questions (FAQ)

Common questions about Staphen (FAQ)

Q: Is it normal to feel a bit nauseous when first starting Staphen?

Regulatory documents state that mild stomach upset, including nausea, is a commonly reported side effect. Some official resources note that if nausea occurs, taking the medicine with a small amount of food might be an option, though the primary instruction remains to take it on an empty stomach for better absorption.


Q: What are the most commonly reported mild side effects of Staphen?

According to official product information, the most common mild side effects reported include minor stomach disturbances like nausea and mild diarrhea, as well as general symptoms such as dizziness and headache. These are categorized as very common or common in clinical trials.


Q: How long does Staphen stay in your system after you stop taking it?

Pharmacokinetic studies reported in official documents indicate that the drug has an elimination half-life of approximately 1.3 to 1.4 hours in adults. Based on the reported half-life, the medication is generally expected to be cleared from the body within a day after the final dose in individuals with normal kidney function.


Q: What are any long-term side effects associated with continuous use of Staphen?

Official regulatory warnings highlight that taking this medicine for prolonged periods, especially over 14 days, is associated with a risk of severe liver damage, which can include hepatitis and cholestatic jaundice. This risk is noted to be higher in older patients, and monitoring of liver function is often required for extended courses of treatment.


Q: Can Staphen affect my ability to drive or operate machinery?

Official consumer medicine information advises caution regarding driving or operating machines. The reason is that Staphen may cause undesirable effects such as dizziness or allergic reactions, which could potentially influence an individual's judgment or physical ability.


Q: Is it possible for Staphen to lose effectiveness over time?

Official warnings note that the prolonged use of any antibiotic can occasionally lead to the overgrowth of non-susceptible organisms, such as certain fungi or bacteria. Regulatory documents emphasize the importance of completing the full course of therapy to prevent this potential loss of effectiveness.


Q: Why do some people say Staphen caused them headaches?

Headache is listed in official documents as a commonly reported side effect of the medicine. In rare instances, headaches are also associated with more serious effects like anemia (low red blood cell count) that are sometimes noted in regulatory summaries.


Q: Can Staphen cause changes in mood or anxiety levels?

Central Nervous System (CNS) side effects have been reported rarely with this medicine. These effects include dizziness and convulsions. While official documents mention these rare CNS effects, specific changes to mood or anxiety levels are generally not listed as known adverse effects.


Q: What should I do if my side effects from Staphen don't go away after a week?

Official patient information advises that if common side effects persist, are bothersome, or become severe, guidance from a healthcare professional should be sought. Signs of a severe or allergic reaction, such as swelling or difficulty breathing, warrant immediate emergency medical evaluation.


Q: Can Staphen interact with common medications for diabetes or high cholesterol?

Specific medications for diabetes or high cholesterol are generally not listed as known interacting drugs in the official summaries. It is advised that individuals always check with a healthcare professional regarding all other medicines, as official guidance requires providers to be aware of all co-administered therapies.


Q: Can Staphen cause dry mouth or changes in taste?

Consumer regulatory sheets note that the oral liquid form of Staphen is known to have a bitter taste. While dry mouth is not commonly listed, the medication can lead to overgrowth of fungi (oral thrush), which can cause discomfort or a change in sensation in the mouth.


Q: How does the body break down and excrete Staphen?

The drug is eliminated from the body primarily through the kidneys, a process known as renal excretion. For this reason, official prescribing guidelines require dose adjustments for patients who have severe renal impairment, as their body cannot clear the drug as efficiently.


Q: What is the research status of Staphen, are new studies ongoing?

Staphen is a well-established medication that has been approved for a long time. Official regulatory pages focus on monitoring its approved uses and safety profile through post-market surveillance. These documents typically do not provide information on whether new clinical trials for different uses are currently ongoing.


Q: Is it better to take Staphen with food or on an empty stomach?

Regulatory instructions strictly state that the medication is best taken on an empty stomach to ensure proper absorption into the bloodstream. This means taking it one hour before a meal or two hours after eating. However, official resources also mention that administration with a small amount of food is sometimes considered if stomach irritation is a factor.


Q: Does Staphen have a known risk for dependency?

Official consumer information sheets confirm that this medication, which is an antibiotic, is not known to be addictive and does not have a risk for dependency.


Q: Why is consistency important when taking Staphen?

The medicine is often prescribed on a regular, six-hourly schedule. Consistency in taking the drug at the prescribed intervals is important to maintain a sufficient and consistent concentration of the antibiotic in the bloodstream to effectively eliminate the bacteria.


Q: Can Staphen interact with other prescribed medications like blood thinners?

Yes, official regulatory documents confirm that Staphen is known to interact with certain prescribed anticoagulant medications, specifically Warfarin. Due to this potential interaction, official prescribing guidelines require close monitoring of the anticoagulant effects when Staphen is co-administered.


Q: Can taking Staphen affect blood pressure readings?

Specific changes to blood pressure readings are not commonly listed among the known adverse effects in official regulatory summaries. Individuals who are concerned about blood pressure should discuss this with their healthcare provider.


Q: Is Staphen known to cause allergic reactions?

Yes, Staphen is absolutely contraindicated (must not be used) in anyone with a history of hypersensitivity or allergic reaction to this drug or any other penicillin-class antibiotic. Severe allergic reactions are rarely reported, and signs of a serious reaction warrant immediate emergency medical evaluation.


Q: Why is Staphen sometimes prescribed over similar drugs?

Staphen is classified as a beta-lactamase resistant penicillin in official drug summaries. This means its structure is stable against bacterial beta-lactamase enzymes, making it effective against common bacterial infections, such as staphylococcal infections, where other penicillins would be broken down and inactivated.

How should Staphen be stored and disposed of?

How to Store and Dispose of Staphen: Official Regulatory Information

Storage of Staphen must strictly follow the conditions defined in the official labeling to ensure product stability and efficacy. The medication must be kept within the specified temperature range (e.g., room temperature) and protected from both light and moisture.

Mandatory Storage Constraints:

Constraint Requirement
Temperature Store within the range specified on the label.
Protection Keep protected from light and humidity.
Container Must remain in the original, tightly closed packaging.
Prohibited Do not freeze or expose to excessive heat.

After initial opening or preparation, specific products may have a defined in-use shelf-life after which they must be discarded. To prevent harm, all medicine must be kept out of the sight and reach of children.

Disposal:

Do not dispose of unused or expired Staphen via household trash, wastewater, or plumbing, unless explicitly directed otherwise by regulatory labeling. Disposal must be performed according to local governmental regulations, often utilizing a pharmaceutical take-back program or pharmacy collection point.

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

Available in countries:

Equivalent of Staphen found in:

A-Z Index: