How long does ceftiofur last? A guide to the duration and pharmacokinetics of this veterinary antibiotic

October 10, 2025 •

4 min read

The duration of ceftiofur's effectiveness can range from just a few hours to over a week, depending on the specific formulation and animal species. Understanding how long does ceftiofur last is crucial for veterinarians to ensure therapeutic success and minimize the development of antibiotic resistance.

Quick Summary

The duration of ceftiofur is highly variable, determined by its formulation, with short-acting versions requiring daily doses and long-acting ones providing extended therapy. Pharmacokinetics differ significantly across species, impacting dosing frequency and overall effectiveness for treating bacterial infections in animals.

Key Points

Formulation is Key: Ceftiofur's duration varies dramatically, from short-acting daily injections (sodium, hydrochloride) to long-acting sustained-release formulas (crystalline free acid, CCFA) that can last over a week.
Species-Specific Duration: The drug's half-life and effective duration differ significantly between species, with CCFA providing 7 days of coverage in cattle but requiring two doses over 10 days for horses.
Infection Affects Efficacy: An animal's health status can alter ceftiofur's pharmacokinetics. For example, infected pigs clear the drug more quickly than healthy pigs, which can reduce its duration of action.
Dosing is Time-Dependent: Ceftiofur's efficacy is dependent on maintaining drug concentrations above the Minimum Inhibitory Concentration (MIC) for the target bacteria over a specific duration, not on achieving high peak levels.
Withdrawal Periods Vary: The time required before an animal can be slaughtered for human consumption (withdrawal period) varies significantly based on the formulation, species, and administration route.

Ceftiofur is a third-generation cephalosporin antibiotic widely used in veterinary medicine to treat a variety of bacterial infections in livestock, horses, and other animals. Its effectiveness is time-dependent, meaning drug concentrations must remain above the minimum inhibitory concentration (MIC) for the target bacteria for a specific duration to be effective. The answer to how long ceftiofur lasts is not a single number, but rather a variable determined by the specific formulation, species, dosage, and the animal's overall health.

Short-Acting vs. Long-Acting Ceftiofur

The most significant factor determining ceftiofur's duration of action is its formulation. Different preparations are designed for distinct therapeutic needs, affecting how quickly the drug is absorbed, metabolized, and eliminated from the body. The two primary types are short-acting and long-acting formulations.

Short-Acting Formulations (Sodium and Hydrochloride)

These are typically administered via daily intramuscular (IM) or subcutaneous (SC) injections. The drug is absorbed relatively quickly, reaching peak plasma concentrations within a few hours. However, the therapeutic levels decline over the subsequent hours, necessitating repeated daily injections to maintain bactericidal efficacy. Ceftiofur sodium, for instance, is rapidly metabolized and eliminated.

Cattle: A short-acting ceftiofur hydrochloride (e.g., EXCENEL RTU) is often administered daily for three to five days to treat bovine respiratory disease (BRD) or metritis.
Swine: Short-acting versions might be used daily for up to three days to treat bacterial pneumonia.
Other Animals: In smaller animals like cats, the half-life can be longer than some short-acting options, but daily dosing is still standard.

Long-Acting Formulations (Crystalline Free Acid)

Long-acting formulations, such as ceftiofur crystalline free acid (CCFA), are engineered for sustained release. These are oil-based suspensions that, when injected, create a depot at the injection site from which the drug is slowly released over an extended period. This reduces the need for multiple, frequent injections, which is beneficial for animal welfare and compliance.

Cattle: A single dose of long-acting CCFA (e.g., Excede) can provide up to seven days of therapy for conditions like BRD and foot rot.
Swine: A single dose of CCFA can also provide long-lasting protection for up to seven days against swine respiratory disease.
Horses: In equines, two doses of CCFA administered four days apart provide a full 10-day course of therapy for lower respiratory tract infections.
Nondomestic Species: Extended-release preparations are particularly useful for treating nondomestic species, minimizing the stress of repeated handling.

Species-Specific Pharmacokinetics and Duration

Beyond the formulation, the animal species plays a significant role in how ceftiofur is metabolized and how long it remains effective. Key pharmacokinetic parameters, such as elimination half-life ($$t_{1/2}$$), differ considerably.

Cattle: The long-acting CCFA formulation is designed to maintain therapeutic plasma levels for seven days. Studies involving multiple injections for metritis confirmed that therapeutic levels are sustained for the duration of the treatment period.
Swine: In pigs, the kinetics of ceftiofur can be influenced by underlying infections. For example, pigs with Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) show a faster drug clearance and lower plasma concentrations compared to non-infected pigs. This highlights how a disease state can affect duration.
Horses: With the CCFA formulation, therapeutic concentrations are sustained for four days after the first dose and six days after the second, ensuring coverage for the full 10-day period.
Cats: The half-life for some ceftiofur formulations in cats is relatively long compared to other species, which is beneficial for treatment. A study on ceftiofur sodium in cats predicted effective treatment with once-daily dosing for susceptible bacteria.
Rabbits: Research has shown CCFA in rabbits to have a terminal half-life of over 42 hours, indicating prolonged presence in the system.
Avian Species: Studies on birds, such as ring-necked doves, have shown a single CCFA dose can maintain plasma concentrations above the MIC for at least 108 hours.

Factors Influencing Ceftiofur's Duration

Several physiological and pathological factors can alter how long ceftiofur remains active in an animal's system:

Renal and Hepatic Function: Since ceftiofur is eliminated via the kidneys and liver, impaired function in these organs can lead to slower clearance and a longer-lasting effect.
Infection Status: As seen in the swine example, an existing infection can significantly alter the body's metabolism and clearance of the antibiotic.
Route of Administration: The speed of absorption and resulting plasma concentration profile vary depending on whether the injection is intramuscular or subcutaneous.
Drug-Protein Binding: Ceftiofur is highly protein-bound. For time-dependent antibiotics like ceftiofur, efficacy depends on the concentration of the free, unbound drug remaining above the MIC for the appropriate duration.

Comparison of Ceftiofur Formulations


Feature	Short-Acting (e.g., Sodium, HCl)	Long-Acting (Crystalline Free Acid)
Mechanism	Rapid release from injection site.	Sustained release from oil-based depot.
Administration	Daily injections for several days.	Single or double injection regimen.
Duration of Effect	Therapeutic levels maintained for ~24 hours, requiring re-dosing.	Provides therapeutic levels for 7-10 days, depending on species.
Best For	Conditions requiring daily monitoring or short, intense courses of therapy.	Large animal groups where handling is difficult; chronic or longer infections.
Examples	Naxcel, Excenel	Excede

Conclusion

In summary, the question of how long does ceftiofur last has a complex answer that depends heavily on the specific formulation and the species being treated. While short-acting forms require daily administration to maintain therapeutic concentrations, the long-acting crystalline free acid (CCFA) version is designed to provide effective levels for up to a week or more with a single dose. Veterinary professionals must carefully consider these factors, along with species-specific pharmacokinetics and the animal's health status, to select the appropriate formulation and dosing schedule. This tailored approach is essential for successful treatment outcomes and responsible antimicrobial stewardship.

Resources

For more detailed product information on specific formulations like Excede, please visit the official manufacturer's website.

Excede® STERILE SUSPENSION – Dairy Cattle Anti-infective

Frequently Asked Questions

Short-acting ceftiofur (sodium, hydrochloride) is absorbed and eliminated quickly, requiring daily injections. Long-acting ceftiofur (crystalline free acid, CCFA) is formulated for a sustained release from the injection site, providing therapeutic levels for up to seven days or more with a single dose.

In cattle, a single dose of a long-acting formulation like ceftiofur crystalline free acid (Excede) is designed to provide up to seven days of therapy for conditions such as bovine respiratory disease (BRD) and foot rot.

For lower respiratory tract infections in horses, a long-acting ceftiofur (CCFA) is given in two doses, four days apart. This regimen provides a full 10-day course of antimicrobial coverage.

Not necessarily. For instance, studies in pigs infected with PRRSV showed that they cleared ceftiofur more rapidly than non-infected pigs, resulting in lower drug concentrations and a shorter duration of effective action.

Several factors affect ceftiofur's duration, including its formulation (short vs. long-acting), the animal species, the route of administration, the animal's overall health (especially kidney and liver function), and whether there is a pre-existing infection.

Yes, withdrawal periods vary significantly by formulation, species, dosage, and route of administration. For example, withdrawal periods for meat range from a few days for some short-acting products to 71 days for some long-acting products in pigs.

No, ceftiofur is poorly absorbed after oral administration. It is typically administered via intramuscular or subcutaneous injection to ensure rapid and effective absorption into the bloodstream.