Cefdin 300

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Cefdin 300

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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 Cefdin 300

What is Cefdin 300?

Cefdin 300 is a prescription medication containing the active ingredient cefdinir. It belongs to a class of drugs known as third-generation cephalosporin antibiotics. These medications are used to treat various types of infections caused by bacteria.

Mechanism of Action

Cefdinir works by interfering with the way bacteria build their cell walls. A stable cell wall is necessary for bacteria to survive and multiply. By disrupting the synthesis of this wall, the medication causes the bacterial cell to weaken and eventually break apart, effectively stopping the spread of the infection in the body.

Therapeutic Use

As an antibiotic, Cefdin 300 is specifically designed to target bacterial organisms. It is not effective against viral infections, such as the common cold or the flu. Healthcare providers typically prescribe this medication for common bacterial conditions, which may include:

  • Respiratory tract infections: Such as community-acquired pneumonia or acute exacerbations of chronic bronchitis.
  • Sinus and throat infections: Including acute maxillary sinusitis and pharyngitis or tonsillitis.
  • Skin infections: Uncomplicated infections of the skin and skin structures.

Pharmacological Profile

Cefdinir is noted for its broad-spectrum activity, meaning it can be effective against a wide variety of both Gram-positive and Gram-negative bacteria. After oral administration, the medication is absorbed into the bloodstream and distributed to the site of the infection to begin the therapeutic process.

What side effects are possible with Cefdin 300?

Possible Side Effects and Safety Information

This section summarizes the officially documented adverse reactions and safety considerations for Cefdin 300, strictly based on authoritative government regulatory documents.

Documented Adverse Reactions

Side effects are categorized by frequency observed in clinical trials and post-marketing reports:

  • Common (occurring in 1% or more of patients): Diarrhea is the most common adverse reaction reported.
  • Uncommon (occurring in less than 1% of patients): Nausea, abdominal pain, headache, and vaginal moniliasis (yeast infection).

Serious and Clinically Significant Safety Concerns

Severe reactions documented in official safety information include:

  • Gastrointestinal: Severe, watery, or bloody diarrhea, which may be a sign of pseudomembranous colitis (a serious, potentially life-threatening bowel condition).
  • Hypersensitivity: Severe allergic reactions (anaphylaxis, angioedema) and cross-sensitivity with penicillin antibiotics.
  • Skin: Severe skin reactions such as Stevens-Johnson syndrome and toxic epidermal necrolysis.
  • Other: Renal dysfunction (including acute renal failure) and hepatic dysfunction.

Key Safety Limitations and Considerations

  • Kidney Function: Patients with markedly compromised renal function (creatinine clearance less than 30 mL/min) require a dose adjustment because the drug's elimination is reduced in this population.
  • Drug Interactions: Medications such as antacids (containing aluminum or magnesium) and iron supplements must be administered at least two hours before or after Cefdin 300 to prevent a significant reduction in drug absorption.
  • Contraindications: Cefdin 300 is contraindicated in individuals with a known hypersensitivity to cephalosporin antibiotics or a history of anaphylactic reaction to penicillin.

Overdose and Emergency Response

The official regulatory profile for Cefdin 300 overdose focuses on the identification of severe manifestations and mandated emergency actions. Documented overdose presentations, consistent with beta-lactam antibiotic overdosage, include gastrointestinal effects such as nausea, vomiting, diarrhea, and epigastric distress. A critical and severe manifestation documented in the prescribing information is the potential for a seizure or convulsion, affecting the Central Nervous System. Immediate emergency medical attention is required in all suspected cases, and official guidance instructs contacting the Poison Help line at 1-800-222-1222. Urgent help is necessitated if the person has collapsed, had a seizure, has trouble breathing, or cannot be awakened.

Due to the drug’s primary elimination route, patients with markedly compromised renal function are at an elevated risk for prolonged high plasma concentrations and subsequent toxicity. Management efforts are centered on the removal of Cefdinir from the body. Hemodialysis is specifically documented as a procedure that can remove the drug and may be utilized in the event of a serious toxic reaction. The regulatory basis for treatment focuses on procedural support since information on overdosage in humans is constrained.

Therapeutic Uses of Cefdin 300

What Cefdin 300 Treats: Main Uses and Benefits

Cefdinir is generally used to help treat infections caused by bacteria, such as those affecting the airway tubes, lungs, skin, ears, sinuses, throat, and tonsils.

Cefdin 300 is commonly used across domains where additional symptomatic support is needed, primarily addressing acute bacterial illnesses. This includes specific conditions such as acute otitis media, sinusitis, pharyngitis/tonsillitis, community-acquired pneumonia, and uncomplicated skin and skin structure infections. The medication is applied in contexts where clinical signs suggest a bacterial etiology, and symptoms cluster around localized pain, fever, and inflammation.

“The medication is applied in addressing conditions where symptoms create noticeable physiological strain, which contributes to improved comfort during periods of heightened symptoms.”

The use of Cefdin 300 supports the management of disruptive symptoms like productive cough, acute breathing difficulties, and pronounced redness or tenderness on the skin. It may assist with maintaining functional stability and helps patients cope more steadily with challenging infectious episodes.


Quick Fact: Relief for Systemic Imbalance and Physical Discomfort

Cefdin 300 is relevant for easing symptoms related to systemic imbalance and physical discomfort associated with bacterial infection, such as fever, earache, and inflammation in the sinuses or throat.

Regulatory References

  1. Cefdinir: MedlinePlus Drug Information

Eligibility and Restrictions for Use

Who can and cannot use Cefdin 300

The eligibility for using Cefdin 300 is defined by official regulatory documentation, focusing on patient age, hypersensitivity history, and specific health conditions.

Contraindicated Populations

Use of Cefdinir is contraindicated for any patient with a known allergy or history of a serious hypersensitivity reaction to the active ingredient, Cefdinir, or any other antibiotic belonging to the cephalosporin class.

Age-Related Eligibility

The medication is approved for use in adults and adolescents (13 years of age and older) and for pediatric patients from 6 months through 12 years of age. Safety and efficacy have not been established in infants younger than 6 months. For older adults, no specific adjustment is required based on age alone, provided renal function is normal.

Condition-Based Restrictions

Eligibility is restricted for patients with markedly compromised renal function (creatinine clearance less than 30 mL/min). These individuals require conditional use, which involves modification. Caution is also required for patients with a history of colitis or severe diarrhea, as noted in official warnings regarding gastrointestinal conditions. For women, Cefdinir is documented as Pregnancy Category B and was not detected in human breast milk in regulatory studies.

What should I know about interactions with other medicines?

Cefdin 300 Interactions with other medicines and products

Official regulatory information documents interactions that affect the exposure of Cefdinir or its pharmacodynamic activity with other products.

Interacting Product Category Documented Interaction Outcome
Antacids (Magnesium/Aluminum) Significantly reduces Cefdinir absorption and plasma levels.
Iron Supplements (including multivitamins) Significantly reduces Cefdinir absorption, potentially by up to 80% with therapeutic doses.
Warfarin (Anticoagulant) Increases the risk of bleeding and potential prolongation of Prothrombin Time or INR.
Probenecid (Uricosuric agent) Inhibits renal excretion of Cefdinir, resulting in increased Cefdinir plasma concentrations.

The absorption interactions with Antacids and Iron Supplements require a specific timing constraint: Cefdinir must be administered at least two hours before or two hours after these products. No formal contraindicated combinations are documented based on drug-drug interaction risk.

Regulatory documents also note specific constraints related to patient status and laboratory tests. Systemic exposure to Cefdinir is increased in geriatric patients and those with severe renal impairment (Creatinine Clearance < 30 mL/min) due to reduced clearance. Additionally, Cefdinir may cause false-positive results for ketones in urine (nitroprusside tests) and for glucose in urine (Benedict's or Fehling's solutions).

Mechanism of Action

Irreversible Inhibition of Bacterial Cell Wall Construction

Cefdinir, the active compound in Cefdin 300, works by focusing its action on the bacterial cell's structural components. Its beta-lactam ring irreversibly binds to and deactivates Penicillin-Binding Proteins (PBPs), which are the essential enzymes required for the final step of peptidoglycan cross-linking. This mechanism prevents the bacteria from assembling a rigid, protective cell wall.


Cascade of Structural Failure and Bactericidal Action

The resulting physiological consequence of inhibiting PBPs is a catastrophic failure of the bacterial cell's structural integrity. Because the weakened cell wall cannot withstand the high internal osmotic pressure, the bacterial cell swells and rapidly ruptures (lysis), resulting in bacterial cell death. This structure maintains stability against certain bacterial beta-lactamase enzymes, facilitating its PBP engagement.

Dosage and Administration Information

How to Use Cefdin 300

The usage of Cefdinir is defined by standardized dosing and administration conditions. This medication is administered through the oral route (by mouth) and is available in two forms: the 300 mg capsule and an oral suspension (e.g., 125 mg/5 mL) for dosing in pediatric patients.

Standard Dosing Regimens

The established total daily dosage for adults and adolescents is 600 mg. This quantity can be achieved through two primary authorized schedules:

  • Twice Daily Schedule: 300 mg taken every 12 hours.
  • Once Daily Schedule: 600 mg taken every 24 hours (authorized for some, but not all, infections).

Treatment duration is short-term and fixed, commonly ranging from 5 to 10 days, depending on the specific infection being addressed.

Administration Conditions and Adjustments

Cefdinir may be administered with or without food without affecting its systemic availability. A principle for use is the separation from certain compounds: Cefdinir intake is separated by at least 2 hours from aluminum- or magnesium-containing antacids and iron supplements. Failure to observe this timing may interfere with the drug’s intended absorption.

For patients with significantly reduced renal function (creatinine clearance less than 30 mL/min), a dose modification is used. The total daily dose for these adults is reduced to 300 mg once daily to prevent systemic accumulation. Similarly, adjusted dosing is defined for patients undergoing hemodialysis.

Recent Clinical Evidence

RESEARCH EVIDENCE / OVERVIEW OF STUDIES FOR CEFDINIR

This section provides a descriptive overview of the research and study types conducted for Cefdinir (Cefdin 300). It focuses only on what types of outcomes were measured and the populations that were observed in the trials, without making any claims about clinical performance or individual outcomes.


Evidence Base for Respiratory and Throat Infections

Research examined data related to Acute Bacterial Exacerbations of Chronic Bronchitis (ABECB) primarily through prospective, randomized, comparative studies. These trials was evaluated in adults and adolescents, focusing on clinical success rates and microbiological eradication findings. For Community-Acquired Pneumonia (CAP), studies monitored clinical response, bacteriological clearance, and changes noted on lung imaging. Research indicates that measured clinical response outcomes was often comparable to the results described for various oral comparator treatments.

Studies for Pharyngitis/Tonsillitis explored short-course regimens in adults, adolescents, and pediatric patients. These trials measured GABHS eradication and overall clinical success.

Evidence Base for Ear and Skin Infections

Extensive pediatric research was studied for Acute Otitis Media (AOM) in children aged 6 months through 12 years. These studies measured clinical response rates and bacteriological outcomes. Research for Uncomplicated Skin and Skin Structure Infections (uSSSI) focused on adults, adolescents, and pediatric patients, monitoring clinical cure rates and bacteriological findings against specific susceptible strains.

Evidence Gaps and Areas of Uncertainty

Uncertainty remains regarding some subgroup findings, as overall population patterns may mask less conclusive findings for specific groups, such as the youngest pediatric patients. Long-term outcomes are not well characterized, and data describing recurrence or chronic functional measures are limited. The existing research mainly applies to uncomplicated infections, and comparative data is not available for conditions involving deep tissue involvement or complex comorbidities. Study results reflect the specific conditions under which the research was conducted, and the findings describe group patterns, not outcomes for an individual person.

Key Studies & References

  1. FDA Approved Labeling / Prescribing Information for Cefdinir (Omnicef or generic equivalent)
  2. Cefdinir: MedlinePlus Drug Information (NIH)
  3. Cefdinir Drug Information and Mechanism of Action (Drugs.com)

Frequently Asked Questions (FAQ)

Common questions about Cefdin 300 (FAQ)


Q: Is Cefdin 300 considered a strong antibiotic?

A: Cefdin 300 contains Cefdinir, which is classified as a third-generation cephalosporin antibiotic. Official information states that it works through a bactericidal mechanism, meaning it directly kills bacteria. It also has stability against certain bacterial resistance mechanisms, demonstrating its intended activity against susceptible pathogens.


Q: How quickly should I expect Cefdin 300 to start working?

A: According to official pharmacokinetic data, the highest concentration of Cefdinir in the bloodstream occurs approximately 2 to 4 hours after a dose. While the drug is active in the body quickly, the duration of treatment is typically 5 to 10 days. Clinical improvement can vary based on the type and severity of the infection.


Q: What is the average length of treatment with Cefdin 300?

A: The duration of Cefdinir treatment is short-term and is officially defined by the type of infection being addressed. The length of treatment commonly ranges from 5 to 10 days.


Q: Is it necessary to take Cefdin 300 with food?

A: Official administration instructions state that Cefdinir may be taken with or without food without affecting how much of the medicine the body absorbs. However, to avoid reduced absorption, it requires separation from antacids and iron supplements, as detailed in the Interactions section.


Q: Does Cefdin 300 interact with antacids or iron supplements?

A: Yes, Cefdinir interacts significantly with aluminum- or magnesium-containing antacids and iron supplements. These products can drastically reduce the amount of antibiotic absorbed, making it less effective. This significant interaction requires that Cefdinir be administered at least two hours before or two hours after these products to ensure proper absorption.


Q: Can children be prescribed Cefdin 300?

A: Yes, Cefdinir is approved for use in pediatric patients starting from 6 months through 12 years of age, as well as in adolescents and adults. Official data indicates that safety and effectiveness have not been established in infants younger than 6 months.


Q: Can pregnant women be prescribed Cefdin 300?

A: Cefdinir is classified as Pregnancy Category B in the U.S. regulatory system. Animal studies did not show harm to the fetus, but there are no definitive, well-controlled studies in pregnant women. Official guidance indicates it should be used during pregnancy only after a professional assessment of the potential benefits outweighing the potential risks.


Q: Is Cefdin 300 safe for breastfeeding mothers?

A: According to official regulatory studies, Cefdinir was not detected in human breast milk following a single dose of the medication. Standard guidance advises that caution is generally recommended when the medication is given to a woman who is nursing.


Q: Is it normal to feel tired or dizzy while taking Cefdin 300?

A: In clinical trials, headache was listed as an uncommon adverse reaction, occurring in less than 1% of patients. However, symptoms like tiredness or dizziness are not specifically listed among the common or uncommon side effects documented in the official product information.


Q: Does Cefdin 300 change the color of my stool?

A: Yes, regulatory postmarketing reports have noted cases of reddish-colored stools associated with Cefdinir use. This effect is thought to be related to the drug forming a non-absorbable complex with iron metabolites in the body.


Q: Is it true that Cefdin 300 can cause yeast infections?

A: Yes, vaginal moniliasis, which is a type of fungal or yeast infection, is listed in the official safety information. It is considered an uncommon side effect, reported in less than 1% of patients during clinical trials.


Q: Is Cefdin 300 used for ear infections?

A: Yes, Cefdinir is officially indicated for the treatment of certain types of bacterial ear infections, specifically Acute Bacterial Otitis Media, in both children and adults when caused by susceptible organisms.


Q: Why is it important to complete the entire course of Cefdin 300?

A: The official product information emphasizes that Cefdinir, like other antibiotics, should be used correctly to reduce the development of drug-resistant bacteria. Completing the full prescribed course is intended to eliminate the bacteria, which helps prevent the development of resistance and recurrence.


Q: What are the most serious, but rare, side effects of Cefdin 300?

A: Official safety warnings include serious, though uncommon, adverse reactions. These include severe allergic reactions (such as anaphylaxis), severe skin conditions (like Stevens-Johnson syndrome), and serious gastrointestinal issues like severe, persistent diarrhea which may indicate pseudomembranous colitis.


Q: Can Cefdin 300 affect blood clotting?

A: Official documents note that Cefdinir may interact with the anticoagulant Warfarin, potentially causing a prolongation of the Prothrombin Time or INR (measures of blood clotting). Additionally, rare reports of coagulation disorder and bleeding tendency have been documented in postmarketing experience.


Q: Can Cefdin 300 be taken with birth control pills?

A: The drug label does not specifically list an interaction with hormonal contraceptives (birth control pills). However, the effectiveness of oral contraceptives can sometimes be reduced when taken with antibiotics. Concerns about potential interactions should be discussed with a healthcare professional.


Q: Is there a generic version available for Cefdin 300?

A: Yes, Cefdinir is the active ingredient in Cefdin 300 and is widely available as a generic product under the name Cefdinir. It was also previously marketed under the brand name Omnicef.


Q: What types of bacteria is Cefdin 300 effective against?

A: Official microbiology data confirms Cefdinir is active against a range of Gram-positive bacteria, such as Staphylococcus aureus and Streptococcus pneumoniae, and Gram-negative bacteria, including Haemophilus influenzae and Moraxella catarrhalis. It is used only against susceptible strains.


Q: Can Cefdin 300 be used to treat skin infections?

A: Yes, Cefdinir is officially indicated for treating Uncomplicated Skin and Skin Structure Infections caused by susceptible bacteria. These include infections of the skin and skin structure that fall under the 'uncomplicated' classification in official documentation.


Q: Can Cefdin 300 affect liver enzyme levels?

A: Rare adverse events reported in postmarketing experience include signs of hepatic dysfunction. This is related to reports of hepatic dysfunction, which include rare events like acute hepatitis and hepatic failure, as documented in postmarketing experience.


Q: How is Cefdin 300 different from other cephalosporin antibiotics?

A: Cefdinir is classified as a third-generation cephalosporin, which is a distinguishing factor. Compared to older generations in this drug class, third-generation agents typically offer an extended spectrum of activity and increased stability against certain bacterial enzymes that can cause resistance.


Q: What impact does Cefdin 300 have on gut flora?

A: Like other antibiotics, Cefdinir works by killing bacteria, which can disrupt the natural balance of microorganisms (gut flora) in the intestines. This disruption is the reason why diarrhea is the most common adverse reaction reported. In rare, severe cases, this disruption is associated with a condition known as pseudomembranous colitis.


Q: Are there research studies comparing Cefdin 300 to other common antibiotics?

A: Yes, the Clinical Studies section of the official prescribing information includes data from comparative trials. These studies compared Cefdinir's efficacy and safety against other active control treatments for the various infections for which it is indicated.


Q: Is Cefdin 300 effective against 'superbugs' or drug-resistant bacteria?

A: Cefdinir is active against some bacteria that produce beta-lactamase enzymes, which are a common form of resistance. However, it is inactive against certain highly resistant organisms, such as Methicillin-resistant Staphylococci (MRSA).


Q: Can Cefdin 300 cause confusion or changes in mood?

A: While not a common side effect, rare reports from postmarketing experience for Cefdinir and the cephalosporin drug class have noted effects on the central nervous system (CNS). These effects have included serious events such as loss of consciousness or seizures.


Q: Does Cefdin 300 affect the central nervous system?

A: Rare adverse events reported for this drug class and Cefdinir itself have included central nervous system (CNS) effects. These are typically serious, such as seizures and loss of consciousness. This is why caution is generally noted for this class of antibiotics.


Q: How does antibiotic resistance relate to Cefdin 300?

A: Cefdinir's chemical structure gives it stability against certain enzymes that cause resistance (beta-lactamase). However, the label emphasizes that it must be used appropriately to reduce the development of drug-resistant bacteria, as improper use can lead to the drug's effectiveness being diminished over time.


Q: What evidence supports the use of Cefdin 300 for tonsillitis?

A: Clinical trials for Cefdinir demonstrated that it is effective for treating Pharyngitis/Tonsillitis. The evidence showed successful eradication of Streptococcus pyogenes (S. pyogenes), which is the most common bacterial cause of these throat infections.

How should Cefdin 300 be stored and disposed of?

Cefdinir capsules and the unmixed powder for oral suspension must be stored at Controlled Room Temperature (20°C to 25°C or 68°F to 77°F). All forms require protection from light and must be kept from freezing.

  • Capsules must be stored in a closed container in a cool, dry place.
  • The liquid suspension is stable for only 10 days after it is mixed with water and should not be refrigerated. Any remaining liquid must be discarded after this 10-day period.

Disposal of Unused Medicine

To discard unused or expired Cefdinir, follow official regulatory guidelines. The medicine should not be flushed down a toilet or sink. Instead, utilize community drug take-back programs. If a take-back program is unavailable, mix the medicine with an undesirable substance (like coffee grounds or dirt) in a sealed bag and dispose of it in the household trash. Both forms must be kept out of the reach of children.

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

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