Cefacilina

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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 Cefacilina

Cefacilina is the trade designation for the active chemical substance Cefadroxil, a powerful semisynthetic medication classified as a first-generation cephalosporin antibiotic. It is a prescription-only drug whose fundamental purpose is to combat and eliminate susceptible bacterial infections within the body.


Quick Facts

Property Description
Active ingredient Cefadroxil
Form Capsule, Tablet, Oral Suspension
Pharmacological class First-Generation Cephalosporin (Beta-Lactam Antimicrobial)
Common use Anti-infective agent for bacterial pathogens
Origin Semisynthetic

What Type of Antibiotic is Cefacilina?

Cefacilina belongs to the beta-lactam antimicrobial class, specifically categorized as a first-generation cephalosporin. This classification signifies that the drug is structurally related to penicillins but possesses an enhanced stability profile and a distinct spectrum of activity. Cefadroxil is a bactericidal agent with a long half-life, which means the medication is designed to kill bacteria and remains active in the body for a prolonged period. This long half-life is a key differentiator that supports less frequent dosing compared to some older antimicrobial agents, enhancing convenience.


Composition and General Purpose

The medication is a single-ingredient product containing Cefadroxil, which is formulated to be highly stable and suitable for oral administration. It is available in various dosage forms, including traditional capsules and tablets, as well as a powder for reconstitution into an oral suspension. The general purpose of Cefacilina is directly derived from its fundamental bactericidal nature. The substance Cefadroxil is recognized for its efficacy against common skin and urinary tract pathogens. It works by causing the destruction of bacterial cells, thus effectively clearing the infection and restoring the body's natural balance. Its specific mechanism involves the inhibition of cell-wall synthesis, ensuring it is an effective tool against targeted bacterial threats while being completely inactive against viral, fungal, or parasitic causes of illness.

What side effects are possible with Cefacilina?

Possible Side Effects and Safety Information

The official safety profile for Cefacilina (Cefadroxil) details adverse reactions across various body systems and is classified by frequency, consistent with regulatory standards.

Adverse Reaction Classification

Classification System-Organ Class Examples
Common Gastrointestinal disorders (e.g., diarrhea, nausea, vomiting), skin reactions (e.g., rash, pruritus).
Uncommon Infections and infestations (e.g., vaginal mycoses, thrush).
Rare Blood and lymphatic disorders (e.g., eosinophilia, leucopenia), immune system disorders (e.g., angioedema), renal and urinary disorders (e.g., interstitial nephritis).
Very Rare Severe allergic reactions (e.g., anaphylactic shock), certain neurological events (e.g., headache, dizziness).

Serious Adverse Reactions and Key Constraints

Documented serious adverse reactions include Pseudomembranous Colitis, which can range in severity and may occur even up to two months after treatment discontinuation, and severe cutaneous adverse reactions such as Stevens-Johnson Syndrome.

Cefacilina is contraindicated in individuals with a known allergy to the cephalosporin class of antibiotics. Due to documented cross-sensitivity among beta-lactam drugs, caution is warranted in patients with a history of penicillin allergy.

Official labeling addresses special safety considerations: patients with impaired renal function require particular attention, as the drug is substantially eliminated by the kidneys, increasing the risk of adverse effects, including neurological events like seizures. Furthermore, prolonged use may lead to the overgrowth of non-susceptible organisms (superinfection).

Overdose and Emergency Response

Overdose and When to Seek Help

Official regulatory information describes that overdosage of Cefacilina (Cefadroxil) primarily results in gastrointestinal symptoms, such as nausea and vomiting. While these effects are generally the main manifestation, severe overexposure carries a documented potential for neurological complications. Specifically, seizures are a known, albeit rare, severe outcome associated with high systemic levels of this cephalosporin class of antibiotic.


Regulatory Actions and Management

Government guidance requires that individuals seek immediate medical attention or call the Poison Help line upon any suspicion of overdose. If severe manifestations occur, such as collapse, an active seizure, or difficulty breathing, emergency services must be contacted immediately.

Treatment procedures are classified as symptomatic and supportive, as no specific antidote is known for Cefadroxil overdosage. Management involves maintaining and correcting water and electrolyte balance, and monitoring of renal function is necessary. Furthermore, the official labeling notes that patients with markedly impaired renal function carry an increased risk for severe toxicity and neurological adverse effects during overdosage.

Therapeutic Uses of Cefacilina

What Cefacilina Treats: Main Uses and Benefits

Cefadroxil is used to treat certain infections caused by bacteria, such as those of the skin, throat, tonsils, and urinary tract. Cefacilina is commonly used across conditions presenting with acute episodes in the skin, soft tissues, and urinary tract, as well as during symptomatic throat infections like pharyngitis and tonsillitis.

The medication is relevant in clinical settings marked by heightened patient distress associated with conditions where functional stability becomes affected. It helps address symptom clusters that may become intense or disruptive, specifically painful or difficult urination (dysuria), constant urgency, significant soreness, or patterns of redness and localized pain. It is applied in situations involving certain distressing symptoms that interfere with daily functioning.

The therapeutic benefit contributes to improved comfort during these periods of heightened symptoms and assists with maintaining functional stability. Cefacilina may help patients cope more steadily with symptom fluctuations and supports the general well-being during symptomatic phases.

“This application provides supportive relief when symptoms interfere with routine activities, helping to ease the overall symptom load during acute episodes.”

Quick Fact: Symptomatic Support
Cefacilina is commonly used to help manage symptomatic discomfort in conditions where symptoms may intensify temporarily, such as UTIs and acute skin episodes. It is relevant for easing discomfort when symptoms become more noticeable.

Regulatory References

  1. Cefadroxil: MedlinePlus Drug Information

Eligibility and Restrictions for Use

Who Can and Cannot Use Cefacilina?

The official population eligibility for Cefacilina (Cefadroxil) is strictly defined by regulatory documents, outlining populations permitted to use the drug and those for whom use is contraindicated or restricted.


Contraindicated Populations

Cefacilina is contraindicated and must not be used by patients with a documented history of hypersensitivity or severe allergic reactions to the cephalosporin class of antibiotics. Due to the risk of cross-hypersensitivity, patients with a history of severe reactions to penicillins or other beta-lactam drugs are also formally non-eligible for use.


Population Restrictions and Conditional Use

Use is restricted in patients with markedly impaired renal function (e.g., severe kidney impairment). These individuals require mandatory dose adjustment, as defined in the official labeling. The medication should also be used with caution in patients with a history of gastrointestinal disease, particularly colitis.


Age and Physiological Limitations

Population Group Regulatory Eligibility Status
Infants/Children (<6 years) Capsules/tablets are not recommended; oral suspension is typically used.
Children with Renal Insufficiency Not indicated for use in children suffering from renal insufficiency.
Pregnant Women Safe use has not been established; use is discouraged unless clearly needed.
Nursing Mothers Excreted in low concentrations in breast milk; requires strict caution and prescriber consideration.

Eligibility is defined by regulatory standards and is strictly determined by known allergies and specific health conditions.

What should I know about interactions with other medicines?

The interaction profile for Cefacilina (Cefadroxil) is officially documented across several categories defined by regulatory agencies. The primary mechanistic bases include competitive inhibition of renal tubular secretion (a pharmacokinetic interaction) and pharmacodynamic antagonism.


Interaction Scope

Medicinal products or categories with documented interactions include Probenecid (an inhibitor of renal tubular secretion), Live Bacterial Vaccines (e.g., Oral Typhoid Vaccine), Other Nephrotoxic Agents (such as Aminoglycosides), and certain Diagnostic Reagents.


Official Interaction Statements

  • Co-administration with Probenecid is officially documented to increase Cefacilina blood concentrations and prolong its half-life by competitively inhibiting its renal clearance. This interaction is classified as modifying the systemic exposure of the antibiotic.
  • The drug's inherent bactericidal property may result in pharmacodynamic antagonism, which is formally stated to reduce the therapeutic efficacy of live bacterial vaccines. This imposes a formal restriction on simultaneous administration due to the risk of vaccine failure.
  • A regulatory note advises caution regarding the combination with other nephrotoxic agents due to the potential for an additive increase in nephrotoxicity.
  • The medication may interfere with certain laboratory procedures, specifically causing false-positive results when testing for urine glucose using cupric sulfate-type reduction methods.
  • Population-specific interaction notes caution that the drug’s elimination is slower in patients with markedly impaired renal function (creatinine clearance less than 50 mL/min/1.73 m^2), which necessitates an awareness of the increased systemic exposure risk.
  • Timing-based interaction rules officially state the drug may be administered with or without food, as food does not significantly alter drug absorption.

Mechanism of Action

Cefacilina (Cefadroxil) functions as a bactericidal agent by targeting the unique structural integrity of the bacterial cell wall. Its mechanism is the irreversible covalent inhibition of Penicillin-Binding Proteins (PBPs), which are bacterial enzymes essential for cell membrane function. Specifically, Cefadroxil binds to the transpeptidases within the PBPs, halting the final cross-linking step of the peptidoglycan synthesis pathway.

This blockade results in a structurally weak, defective cell wall. The vulnerable bacterial cell, unable to withstand internal osmotic pressure, rapidly swells and bursts—a process termed osmotic lysis. This destruction physically clears susceptible microbial populations. The mechanism is constrained by bacterial counter-mechanisms, such as the production of beta-lactamase enzymes, which hydrolyze the drug's beta-lactam ring, thereby inactivating the molecule and reducing its molecular impact on the PBPs.

Dosage and Administration Information

How to Use Cefacilina

The usage of Cefacilina (Cefadroxil) is governed by specific instructions for use. The medication is strictly intended for oral administration, utilizing available dosage forms such as capsules, tablets, or a reconstituted oral suspension.

Standard adult regimens typically call for 1 g per day, which may be administered as a single daily dose or divided into two equal doses (e.g., every 12 hours). For more complex conditions, such as certain urinary tract infections, the dose may be increased to 2 g per day, always given in two divided doses. The twice-daily or once-daily pattern is supported by the drug's extended half-life.

The medication may be taken with or without food. Taking the dose with food can be utilized to help diminish potential gastrointestinal discomfort. If the oral suspension is prescribed, the powder must be properly reconstituted with water and shaken well before measuring and administering each dose. Capsules and tablets should be swallowed whole with fluid.

Dose adjustments are a mandatory procedural step for patients with impaired renal function (creatinine clearance le 50 mL/min). The regimen is modified by reducing the maintenance dose or extending the interval between doses. Furthermore, treatment of infections caused by Streptococcus requires a minimum course duration of 10 days; the full course must be completed even if symptoms appear to resolve early.

Recent Clinical Evidence

The research on Cefacilina (Cefadroxil) is primarily documented through regulatory-focused clinical trials and Randomized Controlled Trials (RCTs). These studies were designed to examine the medication’s use in treating certain bacterial infections and were used by regulators in the review of the authorized indications. The evidence base for these core indications is characterized as High, reflecting the design and consistency of the clinical study programs.


Evidence for Use in Urinary Tract Infections (UTIs)

Studies examined Cefacilina in adult patients with UTIs caused by susceptible pathogens, such as E. coli. These short-term RCTs compared the drug against other antimicrobial therapies, monitoring outcomes related to bacteriological clearance and clinical resolution of symptoms. Findings describe patterns observed in the studies regarding pathogen clearance over the acute phase. Limitations include that long-term effects are not fully established and evidence is focused on specific, susceptible bacterial strains.


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

Cefacilina was studied for acute, uncomplicated SSSIs like cellulitis and impetigo in both adult and pediatric patients. Researchers used comparative studies and RCTs to monitor short-term changes, primarily measuring rates of clinical resolution and pathogen clearance. The research describes changes measured during the study period, but a key limitation is that results apply mainly to uncomplicated SSSIs, and data for complex infections remain insufficient.


Evidence for Use in Pharyngitis and Tonsillitis

Research examined the drug in adult and pediatric patients with streptococcal pharyngitis and tonsillitis. Trials consistently maintained a treatment duration of at least 10 days, monitoring outcomes related to physical discomfort and bacteriological eradication of S. pyogenes. A significant research gap is documented: no data is available establishing the drug's effectiveness for the prophylaxis (prevention) of subsequent conditions, such as rheumatic fever.


Evidence Gaps and Follow-Up

Studies for all indications require relatively short treatment and observation periods. As a result, there is limited information for long-term outcomes or durability of effect. While research was conducted in pediatric patients, data for other groups, such as pregnant individuals or those with significant comorbid conditions, remain insufficient, and the focus across the research base is on uncomplicated forms of the core conditions.

Key Studies & References Cefadroxil: MedlinePlus Drug Information (Uses and Indications)

Frequently Asked Questions (FAQ)

Common questions about Cefacilina (FAQ)


Q: How quickly should I expect to see an effect after taking Cefacilina?

A: Official regulatory documents indicate that Cefacilina is rapidly absorbed after oral intake. Measurable levels of the medicine in the bloodstream are typically present for up to 12 hours following a dose, reflecting the drug's extended presence in the body. While the drug is active quickly, the time it takes to notice a reduction in symptoms can vary based on the type of infection being treated.

Q: What happens if I miss a dose of Cefacilina?

A: If a dose is missed, official guidance describes that the medicine is generally taken as soon as possible once remembered. However, if it is already close to the time for the next scheduled dose, the regulatory instruction is to skip the missed dose and continue with the regular schedule. Regulatory instructions indicate that the dose should not be doubled to compensate for the missed one.

Q: Are headaches a normal side effect of Cefacilina?

A: Headaches are described in the official product information as a very rare side effect. This classification means that, based on clinical studies, headaches may affect fewer than 1 in 10,000 users. Other more commonly reported side effects typically involve the stomach or skin.

Q: Can Cefacilina cause liver problems?

A: Regulatory literature related to the cephalosporin class of medicines states there have been rare instances of drug-induced liver injury. These events usually involve transient changes in liver enzymes, which may be observed in blood tests. Such reactions are generally described in the literature as being self-limited.

Q: What is the general duration of treatment with Cefacilina?

A: The length of treatment with Cefacilina is dependent on the specific infection being treated. For instance, the required minimum duration for infections caused by Streptococcus bacteria is 10 days. The duration for other types of infections is determined by the healthcare provider based on the condition's severity.

Q: Does Cefacilina lose its effectiveness over time according to studies?

A: Regulatory warnings are in place to reduce the development of drug-resistant bacteria and to preserve the activity of this medicine. Official advice emphasizes that Cefacilina should only be used to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. This warning is included to help reduce the development of resistance and maintain the medicine's activity against targeted bacteria.

Q: What are the general expectations if Cefacilina does not seem to be working?

A: Official information emphasizes that tests, such as Culture and Susceptibility Tests, should be performed both before and during therapy. If the medicine does not appear to be working, this testing procedure is used to confirm that the infection is still caused by bacteria that are susceptible to Cefacilina.

Q: Why do official documents mention certain foods should be avoided with Cefacilina?

A: The official documentation states that Cefacilina may be administered with or without food, as food does not significantly change how the medicine is absorbed. Taking a dose with food is mentioned as a way to help reduce any potential discomfort in the digestive system.

Q: What should I know about taking Cefacilina if I have diabetes?

A: Official labeling notes that Cefacilina may interfere with certain laboratory procedures. Specifically, it can cause false-positive results when testing for sugar in the urine using cupric sulfate-type methods. This is an important consideration for individuals managing conditions that involve monitoring blood sugar.

Q: Is Cefacilina known to cause weight gain or loss?

A: Human adverse reaction data does not formally describe weight gain or loss as a reported side effect of Cefacilina. Non-clinical studies that examined animals noted only slight changes in weight gain in some high-dose groups, but no weight gain or loss claim is described in the human adverse reaction data.

Q: Can Cefacilina affect my sleep?

A: Sleeplessness, also known as insomnia, is described in official product information as a very rare neurological event. This means it is reported infrequently among users of the medicine, affecting less than 1 in 10,000 people.

Q: Is it safe to use Cefacilina if I am pregnant or breastfeeding?

A: Official regulatory documentation states that safe use has not been established in pregnant women, and its use is discouraged unless clearly needed. For nursing mothers, the medicine is known to be excreted in low concentrations in breast milk, and its use requires strict caution and careful consideration.

Q: Will Cefacilina affect the results of any lab tests?

A: Official regulatory warnings confirm that Cefacilina may interfere with certain laboratory procedures. Specifically, it can lead to false-positive results when testing for urine sugar using cupric sulfate-type reduction methods. This may impact the accuracy of these specific diagnostic screens.

Q: What if I experience a mild rash while taking Cefacilina?

A: Rash is classified as a common side effect in official documents. While many rashes are mild, any severe skin reactions, such as blistering, peeling, or a painful rash, are documented to require immediate attention from a healthcare provider.

Q: Is there a generic version of Cefacilina available?

A: Cefacilina is the trade designation for the active ingredient Cefadroxil. Official drug information confirms that the active ingredient is widely available as a generic product.

Q: What is the difference between Cefacilina and amoxicillin?

A: Cefacilina is classified as a first-generation cephalosporin, whereas amoxicillin is a penicillin. Regulatory documents note that because they belong to the broader beta-lactam class, there is a potential risk of cross-sensitivity between cephalosporins and penicillins.

Q: Does Cefacilina have a risk of causing C. difficile infection?

A: Official warnings detail the potential for serious adverse reactions, including Pseudomembranous Colitis, which is often linked to the overgrowth of Clostridioides difficile bacteria. This severe condition can occur during therapy or even up to two months after the medicine is stopped.

Q: Is Cefacilina approved for use in older adults?

A: Official labeling notes that Cefacilina is substantially eliminated by the kidneys. Because older adults are more likely to have reduced kidney function, official documents describe that dose adjustments and monitoring procedures are often applied in this population.

Q: Do studies suggest any potential for developing resistance to Cefacilina?

A: Official regulatory information includes a warning aimed at reducing the development of drug-resistant bacteria. This warning exists to help ensure the long-term activity of Cefacilina and other antibacterial medicines against targeted pathogens.

Q: Are there any specific safety warnings for people with a history of seizures when considering Cefacilina?

A: Regulatory documents state that patients with impaired kidney function have been reported to develop neurological events like seizures due to the drug accumulating in the body. The use of Cefacilina requires caution and monitoring in individuals where this risk of accumulation is present.

Q: Can Cefacilina cause dizziness or affect driving ability?

A: Dizziness is officially described as a very rare neurological event. Patient information indicates that if side effects such as dizziness or tiredness are experienced, activities like driving or operating machinery may need to be avoided until an individual feels well again.

Q: Is it normal to feel tired when taking Cefacilina?

A: Tiredness, also referred to as fatigue, is listed in official documents as a very rare adverse reaction. This means it is an infrequent event, reported in less than 1 in 10,000 users of the medicine.

Q: How is the need for Cefacilina determined by healthcare providers?

A: The need for this medicine is determined by using it only to treat infections that are proven or strongly suspected to be caused by susceptible bacteria. Healthcare providers rely on tests, such as Culture and Susceptibility Tests, to confirm that Cefacilina is the appropriate choice for the infection.

Q: Can Cefacilina affect blood sugar levels?

A: The medicine is known to interfere with certain laboratory procedures, specifically causing false-positive results when testing for sugar in the urine using cupric sulfate-type reduction methods. This affects the test results but does not mean the medicine directly changes a person's blood sugar level.

How should Cefacilina be stored and disposed of?

How to Store and Dispose of Cefacilina (Cefadroxil)

Official labeling defines specific storage conditions to maintain the medicine's stability and efficacy.


Storage Requirements

Dosage Form Mandatory Storage Condition
Capsules/Tablets Store at Controlled Room Temperature, 20 C to 25 C (68 F to 77 F). Protect from moisture.
Oral Suspension (Reconstituted) Must be stored in a refrigerator (2 C to 8 C). Do not freeze.

The reconstituted suspension is stable for a maximum of 14 days and must be discarded after this period. All forms must be stored in a tightly closed container and kept out of the sight and reach of children.


Disposal Instructions

Unused or expired Cefacilina should be disposed of using official drug take-back programs. If this is not possible, the medicine should be mixed with an unappealing substance, sealed in a plastic bag, and placed in the household trash. Do not dispose of the medication by flushing it down a toilet or drain.

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

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