Keforal

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Medically reviewed

Rosario Oropesa

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 Keforal

Quick Facts

Property Description
Active ingredient Cephalexin (Cefalexin)
Form Capsule, Tablet, Powder for oral suspension
Pharmacological class First-generation Cephalosporin, beta-Lactam Antibiotic
Common use Systemic treatment of bacterial infections
Origin Semisynthetic

What is Cephalexin and What Type of Drug is it?

The medication marketed under the trade name Keforal contains the active ingredient cephalexin (INN: Cefalexin), which is classified as a semisynthetic antibiotic used to resolve bacterial infections. It belongs to the cephalosporin family, specifically the first-generation group of beta-lactam antibiotics. Its chemical formula, C16H17N3O4S, confirms it is a compound derived from a natural core but chemically modified to improve its pharmacological profile. Cephalexin is clinically recognized for its reliable effectiveness against Gram-positive bacteria, providing a well-established option for fighting susceptible bacterial pathogens.


How is Cephalexin Classified by its Mechanism?

Cephalexin's action is defined as bactericidal, meaning its primary function is to directly kill the targeted bacteria rather than simply limiting their population growth. It achieves this by disrupting the formation of the bacterial cell wall, a structure that is unique to bacteria. Specifically, the drug binds irreversibly to essential penicillin-binding proteins (PBPs), thereby inhibiting the final cross-linking of peptidoglycan synthesis. This mechanism provides a strong, decisive action against susceptible pathogens.


What Forms of Keforal are Used?

Cephalexin is predominantly designed for oral administration, meaning it is taken by mouth, and is available as solid dosage forms like capsules and tablets, as well as a powder for oral suspension to be prepared as a liquid. The compound is notably acid-stable, a property essential for effective absorption through the gastrointestinal tract. This high oral bioavailability is a critical characteristic that allows the medicine to be used systemically via a convenient, non-invasive route. This ease of use is a differentiating factor, making it a preferred choice when an effective oral antimicrobial agent is required.

Regulatory References

  1. Cephalexin - StatPearls - NCBI Bookshelf
  2. Cephalexin: MedlinePlus Drug Information

What side effects are possible with Keforal?

Possible side effects and safety information

The official safety profile for cephalexin (Keforal) is structured around adverse reactions categorized by frequency and the organ systems affected, based on regulatory documentation from bodies like the FDA and EMA.

Common adverse reactions, occurring in up to 1 out of 10 patients, include diarrhea and nausea. Uncommon events may involve a rise in liver enzymes, eosinophilia, and certain skin reactions like rash and hives (urticaria).

Adverse reactions classified as rare include more serious gastrointestinal effects such as vomiting and abdominal pain, as well as hemolytic anemia, dizziness, and reversible interstitial nephritis.

Specific serious reactions are documented, including the risk of severe, life-threatening allergic responses like anaphylaxis, severe skin conditions such as Stevens-Johnson Syndrome (SJS), and severe gastrointestinal illness like Pseudomembranous Colitis. Symptoms of this colitis may appear during therapy or even months after treatment is complete.

Regulatory notes define safety considerations for specific populations. Patients with renal impairment carry an increased, documented risk of neurotoxicity, which can include seizures, if dosage is not appropriately managed. Furthermore, the drug carries a known potential for cross-allergenicity with penicillin-class antibiotics, which is an established safety constraint. Cephalexin may also cause a false-positive direct Coombs’ test in laboratory assessments.

Overdose and Emergency Response

Overdose and When to Seek Help

Official regulatory information describes specific manifestations and the required immediate actions in the event of a Cephalexin overdose.

Overdose Scope Official Regulatory Descriptions
Documented Manifestations: Overdose presentations are documented to include nausea, vomiting, epigastric distress, diarrhea, and the potential presence of hematuria (blood in the urine).
Severe Outcomes: There is regulatory acknowledgment of the potential for seizures and other neurotoxic effects, such as encephalopathy and myoclonus, which are associated with high concentrations of cephalosporins.
Specific Risks: Patients with impaired renal function and elderly individuals are noted to have a greater risk of severe toxic reactions following overdose due to the drug’s substantial excretion by the kidney.
Mandatory Actions: Upon any suspected overdose, it is officially mandated to seek immediate medical attention or contact a certified Poison Control Center immediately.

Treatment of cephalexin overdose relies on the prompt institution of general supportive measures. Regulatory guidance explicitly states that no specific antidote is known for this medication. Furthermore, procedures like hemodialysis, peritoneal dialysis, and forced diuresis have not been established as beneficial for drug clearance. Therefore, care is focused on managing clinical signs and supporting the patient’s vital functions. If the severe outcome of seizures occurs, official protocols require the drug to be discontinued, and appropriate anticonvulsant therapy administered under strict clinical supervision.

Therapeutic Uses of Keforal

Keforal (Cefalexin) is commonly used across therapeutic domains where short-term symptomatic assistance is appropriate, such as conditions presenting with acute or disruptive episodes caused by susceptible bacteria. This medication is relevant for infections of the respiratory tract (like strep throat), ears, skin and soft tissues, and the urinary tract (UTIs).

It is often applied during phases when symptoms become more noticeable, helping to address symptom clusters that may become intense or disruptive. The medication supports patients during difficult episodes by easing distress and contributing to easing the overall symptom load. For patients experiencing acute discomfort:

“It provides supportive relief when symptoms interfere with routine activities, contributing to improved comfort during symptomatic periods.”

This therapeutic focus means it is applied in scenarios where additional management of discomfort is required, such as alleviating fever, assisting with localized pain, and supporting the management of inflammation at the site of infection.


Quick Fact: Supports management of Symptoms Related to Inflammatory or Irritative States

Regulatory References

  1. NIH MedlinePlus overview of Cephalexin

Eligibility and Restrictions for Use

The eligibility for using Keforal (Cephalexin) is determined by patient history and clinical conditions, as defined in regulatory documents worldwide.

Official Eligibility Constraints

Classification Who Cannot Use (Contraindication) Who Can Use (Established/Conditional)
Absolute Restriction Patients with a known allergy to cephalexin or any cephalosporin-class drug [1.3, 2.1]. Adults and pediatric patients over 1 year of age [1.3, 1.8].
Conditional Restriction Not explicitly established for infants under 1 year of age [1.1]. Pregnancy (Category B/A) and nursing mothers (use with caution) [1.7].

Eligibility is further constrained by specific health conditions:

  • Impaired Renal Function: The medicine must be administered with caution in patients with markedly impaired kidney function, such as severe renal impairment. Care should be taken in the elderly due to the higher likelihood of decreased kidney function [1.6, 2.4].
  • Comorbid History: Caution is explicitly required for patients with a history of gastrointestinal disease, particularly colitis, and those with a history of seizure disorders [1.1, 2.4].

These regulatory constraints ensure the medicine is only used within officially defined patient populations.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The official regulatory documents detail several interaction patterns for cephalexin (Keforal) that primarily concern the drug's clearance pathway and its potential for additive effects with other agents.

Pharmacokinetic and Clearance Interactions

Co-administration with probenecid is noted as a pharmacokinetic interaction that inhibits the antibiotic's renal tubular secretion. This effect increases cephalexin's concentration in the blood, and regulatory labeling advises that this combination is generally not recommended. Cephalexin also affects the clearance of the antidiabetic agent metformin, reducing its excretion and causing an increase in plasma concentrations.

Pharmacodynamic Risks

Concurrent use with oral anticoagulants, such as Warfarin, requires monitoring because it may lead to an altered international normalized ratio (INR) and an increased risk of bleeding. An additive risk of nephrotoxicity is also documented when cephalexin is combined with other medicinal products known to affect kidney function, such as loop diuretics.

Food and Supplement Restrictions

While food does not significantly alter the total amount of cephalexin absorbed, the drug’s absorption is documented to be reduced by mineral supplements. Specifically, products containing zinc must be administered at least three hours after cephalexin to minimize this absorption interference.

Procedural Interactions

Cephalexin use can cause a false-positive reaction for glucose in urine tests when using Benedict’s or Fehling’s solutions. A positive direct Coombs' Test may also occur during therapy.

Mechanism of Action

Targeted Inhibition of Bacterial Cell Wall Construction

Keforal (cephalexin) exerts its action by irreversibly inhibiting a key enzyme group known as Penicillin-Binding Proteins (PBPs), which are located in the bacterial cytoplasmic membrane. The drug's beta-lactam structure acts as a molecular mimic, allowing it to covalently acylate the active site of the PBPs

. This interaction permanently halts the transpeptidation (cross-linking) step of peptidoglycan synthesis, which is essential for assembling the rigid cell wall structure.


Mechanism of Lysis and Bactericidal Effect

Because the structural backbone of the microbe is incomplete, the bacterial cell wall becomes mechanically compromised and highly unstable. This failure in structural integrity prevents the cell from counteracting its own high internal osmotic pressure. As a direct consequence, the bacterial cell wall ruptures and the contents spill out, a process termed lysis. This cascade ultimately produces a bactericidal physiological effect, which leads to the elimination of the targeted bacterial population from the affected area.

Dosage and Administration Information

How to Use Keforal: Clinical Administration Guidelines

Keforal (cephalexin) is prescribed for oral administration only, available as capsules, tablets, and a powder for oral suspension. The method of use is governed by clinical specifications regarding dosage, timing, and duration.


Standard Dosing and Schedule

The typical adult daily dose ranges from 1 gram to 4 grams, which is divided into equal portions taken multiple times throughout the day. Standard regimens usually involve administration every 6 hours (four times daily) or every 12 hours (twice daily) to ensure consistent therapeutic levels. Cephalexin may be administered with or without food, as its absorption is not significantly altered by meals.


Usage Patterns and Adjustments

Treatment duration is typically 7 to 14 days, based on the type and severity of the infection. However, a minimum of 10 days of therapy is required for infections caused by beta-hemolytic streptococci to prevent complications.

For pediatric patients over one year old, dosing is based on body weight, commonly ranging from 25 to 50 mg/kg/day in divided doses. A critical procedural condition is the need for dose adjustment in cases of impaired kidney function. When renal function is markedly impaired, the total daily dosage must be reduced in accordance with the patient's creatinine clearance to prevent drug accumulation. The powder for oral suspension requires reconstitution with water and must be shaken well before each dose is measured accurately.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Keforal


Evidence for Use in Skin and Skin Structure Infections (SSSI)

Research into Keforal (cephalexin) for skin infections, such as cellulitis and impetigo, primarily involves short-term Randomized Controlled Trials (RCTs) and systematic reviews. These studies were used in a research context exploring how symptoms change over defined treatment periods. Researchers typically studied outcomes related to Clinical Success Rate and monitored changes in infection-related symptoms (e.g., pain, swelling), as well as the microbiological eradication of susceptible bacteria like S. aureus or S. pyogenes at the infection site.

Studies exploring short-term symptom changes documented the proportion of patients meeting pre-defined clinical endpoints for their acute or disruptive episodes. Findings describe patterns of evolution in localized signs of infection, such as observed changes in redness and tenderness, over the observation period. What remains uncertain is the need for more long-term data regarding the durability of the outcome, as most trial follow-up durations were limited.


Evidence for Use in Genitourinary Tract Infections (UTI)


The evidence base for Keforal in uncomplicated urinary tract infections includes Randomized Controlled Trials (RCTs) and specialized Pharmacokinetic (PK) research. The PK studies, which monitor how the medicine moves through the body, documented concentrations in the urinary tract, which is relevant in trials assessing short-term symptom patterns. Research examined outcomes related to microbiological eradication, specifically the rate of sterile urine culture findings, and resolution of symptoms linked to inflammatory or irritative states.

Studies monitored responses over defined, short time intervals, documenting the rates of pathogen absence in cultures and patient-reported outcomes describing perceived discomfort. A key limitation is that contemporary research relies mostly on non-inferiority trials comparing Keforal to other established antibiotics, rather than against a placebo. Additionally, follow-up durations were limited, meaning information about the rates of recurrent UTIs in the specific context of initial Keforal treatment is not fully established.


Evidence in Special Patient Populations and Research Gaps

Research has explored the use of Keforal across different age groups, including Pediatric patients (children) and Older Adults. Studies in children have examined its role in conditions like skin infections and strep throat. Research also specifically addressed the use of Keforal in individuals with renal impairment by documenting its pharmacokinetic profile in these circumstances. Subgroup findings for patients with complex comorbid conditions remain uncertain.

The research for Keforal's core uses has explored various aspects, but several areas remain where research is ongoing or still needed. Much of the comparative evidence is historical, and there is limited information for long-term outcomes, such as rates of infection recurrence over a year or more. The evidence quality varies across studies, especially those focusing on less-common infections or specific patient subgroups.

Key Studies & References

  1. Label: CEPHALEXIN tablet - FDA DailyMed
  2. Cephalexin: StatPearls (Overview of Pharmacokinetics, Indications, and Renal Elimination)

Frequently Asked Questions (FAQ)

Common questions about Keforal (FAQ)

Q: Why do doctors often prescribe Keforal for skin infections?

A: Keforal (cephalexin) is officially indicated for the treatment of skin and skin structure infections. Regulatory documents confirm its effectiveness against susceptible bacteria, such as Staphylococci and Streptococci, which commonly cause these types of infections. Its use is established for conditions like cellulitis and impetigo.

Q: Can Keforal treat ear infections in adults?

A: Yes, official indications for Keforal include the treatment of Otitis media, which is the medical term for a middle ear infection. It is prescribed for ear infections caused by susceptible organisms like S. pneumoniae and Staphylococci. A healthcare provider must determine the appropriate course of treatment for an ear infection.

Q: What happens if I forget to take a Keforal dose?

A: Regulatory guidance suggests taking a missed dose as soon as it is remembered, unless it is nearly time for the next scheduled dose. If it is almost time for the next dose, the missed one should generally be skipped, and the regular schedule continued. Official patient information advises against taking a double dose to compensate for a forgotten one.

Q: Can Keforal cause a yeast infection?

A: Yes, official safety information lists vaginal candidiasis (a common yeast infection) and oral thrush as possible side effects of Keforal. Antibiotics can sometimes disrupt the natural balance of bacteria and fungi in the body, which can lead to an overgrowth of yeast.

Q: Does Keforal interact with birth control pills?

A: While Keforal is not generally known to stop hormonal birth control from working, severe diarrhoea can potentially interfere with the pill's absorption. Official information indicates that if severe diarrhea occurs, consulting the patient information for specific birth control is advised.

Q: Are there any foods I should avoid while on Keforal?

A: Keforal can be taken with or without food. However, official information notes that the mineral supplement zinc can reduce the antibiotic's absorption. To minimize interference with absorption, products containing zinc are typically suggested to be taken at least three hours after Keforal.

Q: What's the difference between Keforal and cephalexin?

A: Cephalexin is the non-proprietary or generic name for the active ingredient in the medicine. Keforal is a specific trade name or brand name used by a manufacturer to market the drug. They refer to the same chemical compound used to treat bacterial infections.

Q: Can children take Keforal?

A: Yes, Keforal is approved for use in pediatric patients, typically those over one year of age. The specific dosage for children is calculated based on their body weight and the type of infection being treated.

Q: Is Keforal safe for pregnant women to use?

A: Official regulatory guidelines indicate that Keforal is generally considered acceptable for use during pregnancy, as no evidence suggests it causes harm to the baby. Any medication use during pregnancy requires review by a healthcare provider.

Q: What precautions should be taken when giving Keforal to the elderly?

A: Caution is specifically advised for elderly patients due to the higher likelihood of reduced kidney function. If kidney function is significantly impaired, the dosage of Keforal may need adjustment to prevent the drug from accumulating in the body.

Q: Can Keforal cause dizziness or drowsiness?

A: Yes, official safety documents list dizziness (rare) and drowsiness (frequency not known) as possible side effects. Due to the potential for these side effects, activities requiring mental alertness, such as driving or operating machinery, may be impacted until a person knows how the medicine affects them.

Q: Can Keforal be used to prevent infections?

A: In addition to treating active infections, Keforal has a role in prophylaxis (prevention). It is approved for use as an alternative for the prevention of bacterial endocarditis in individuals who are allergic to penicillin and are undergoing certain medical or dental procedures.

Q: How does Keforal compare to amoxicillin in terms of use?

A: Keforal (a cephalosporin) and amoxicillin (a penicillin) belong to similar classes of antibiotics and are used to treat a comparable range of bacterial infections. Keforal is often selected as an appropriate alternative for patients with a non-severe allergy to penicillin-class drugs like amoxicillin.

Q: Is it possible to be allergic to both Keforal and amoxicillin?

A: Yes, official safety information notes a potential for cross-allergenicity between penicillin-class antibiotics (like amoxicillin) and cephalosporin-class antibiotics (like Keforal). If a patient has a known penicillin allergy, a healthcare provider will carefully assess the risks before prescribing Keforal.

Q: Can I take ibuprofen or acetaminophen while on Keforal?

A: While regulatory warnings do not list specific major drug interactions with ibuprofen or acetaminophen, they generally advise caution when combining Keforal with other non-prescription medicines. The use of common painkillers should be reviewed by a healthcare provider.

Q: Is it normal to feel tired while taking antibiotics like Keforal?

A: Yes, some official patient information lists unusual tiredness or weakness as a common side effect of Keforal. As the body works to fight the infection, this feeling of fatigue is often experienced.

Q: Does Keforal interact with any common stomach acid reducers?

A: Regulatory patient materials suggest that Keforal may interfere with certain antacids or anti-ulcer medications. Providing a complete list of all medications to a healthcare provider is necessary when taking Keforal.

Q: Can Keforal affect the bacteria in my gut?

A: Yes, like many broad-spectrum antibiotics, Keforal can alter the normal balance of bacteria in the gut. This alteration can sometimes lead to an overgrowth of non-susceptible organisms, which is associated with gastrointestinal issues, including severe intestinal illness.

Q: What kind of research has been done on the long-term effects of Keforal?

A: Keforal is a well-established drug, and research has focused primarily on short-term outcomes for acute infections. Regulatory documents generally note that there is limited data on long-term effects or durability of the outcome, such as infection recurrence over a period longer than one year.

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

A: In individuals with normal kidney function, Keforal is rapidly cleared from the body. Regulatory pharmacokinetic data show that the drug typically persists for 4 to 6 hours and is mostly undetectable within about eight hours after the last dose is taken.

Q: Why do some people feel nauseous when taking Keforal?

A: Nausea is a common adverse effect listed in official safety information for Keforal. While the specific biological reason is not always stated, antibiotics frequently cause gastrointestinal upset due to their effect on the gut’s environment and flora.

Q: What conditions make someone unsuitable for taking Keforal?

A: Keforal is contraindicated (should not be used) if a patient has a known allergy to cephalexin or any other drug in the cephalosporin class. Caution is also required for patients with a history of severe kidney issues, seizure disorders, or gastrointestinal diseases like colitis.

Q: Can I take probiotics at the same time as Keforal?

A: Regulatory-derived information suggests separating the administration of probiotics from Keforal. To reduce the risk of the antibiotic reducing the probiotic’s effectiveness, probiotics are typically suggested to be taken at least one to two hours before or after the Keforal dose.

Q: Does Keforal affect the kidneys?

A: Keforal is excreted primarily by the kidneys, and official information notes that a rare side effect is reversible interstitial nephritis (kidney inflammation). For patients with existing kidney impairment, a dose reduction is necessary to prevent the drug from accumulating and causing toxicity.

Q: Does taking Keforal impact my ability to drive or operate machinery?

A: Official patient information advises that because side effects like dizziness and drowsiness are possible, caution should be exercised. Activities requiring mental alertness, such as driving or operating machinery, may be impacted until a person knows how the medicine affects them.

Q: Why is Keforal sometimes used for dental infections?

A: Keforal is officially indicated for the treatment of certain dental infections caused by susceptible microorganisms. It is effective in treating pathogens that may be present in the oral cavity, making it a suitable choice for this type of infection.

Q: Are there any known interactions between Keforal and herbal supplements?

A: Official guidance emphasizes the need for a healthcare provider to be informed about all herbal products or supplements being taken. While specific interactions are not always listed, a doctor may need to monitor the patient closely for any unexpected effects.

Q: Can Keforal be used for urinary tract infections?

A: Yes, Keforal is one of the medications officially indicated for the treatment of Urinary Tract Infections (UTIs). It is effective against common UTI-causing bacteria such as E. coli and P. mirabilis.

Q: What are the signs that Keforal is working for my infection?

A: Regulatory documents and general patient guidance indicate that symptom improvement should typically begin within two to three days of starting Keforal treatment. The key signs that the medicine is working are the resolution of symptoms like pain, fever, and localized signs of inflammation.

How should Keforal be stored and disposed of?

Storage and Stability

Keforal (cephalexin) storage is determined by the dosage form, ensuring the product's integrity. Solid forms, including capsules and the dry powder for oral suspension, must be stored at Controlled Room Temperature (20 C to 25 C). The product must be protected from light and moisture, and the container must be kept tightly closed.

Once the powder is mixed with water, the suspension requires storage in a refrigerator (2 C to 8 C) and must not be frozen. The prepared suspension is stable for a maximum of 14 days and any remaining portion must be discarded thereafter. All forms of the medicine must be kept out of the sight and reach of children.

Disposal Instructions

Unused or expired Keforal should be properly disposed of via a drug take-back program. If one is unavailable, the medicine should be mixed with an undesirable substance, placed in a sealed container, and discarded in the household trash, following official guidelines.

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

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