Cefdinir is a semisynthetic, third generation cephalosporin antibiotic.
Uses
Cefdinir is used orally for the treatment of mild to moderate upper and lower respiratory tract infections (i.e., acute maxillary sinusitis, acute exacerbations of chronic bronchitis, community-acquired pneumonia) caused by susceptible bacteria. The drug also is used orally for the treatment of acute bacterial otitis media, streptococcal pharyngitis and tonsillitis, and mild to moderate, uncomplicated skin and skin structure infections caused by susceptible bacteria.
Respiratory Tract Infections
Acute Exacerbations of Chronic Bronchitis
Cefdinir is used in adults and adolescents 13 years of age or older for the treatment of acute exacerbations of chronic bronchitis caused by susceptible strains of S. pneumoniae (penicillin-susceptible strains only) or b-lactamase- and non-b-lactamase-producing strains of H. influenzae, H. parainfluenzae, or M. catarrhalis. Although co-trimoxazole generally has been considered the drug of choice for the treatment of upper respiratory tract infections and bronchitis caused by susceptible H. influenzae or M. catarrhalis, second or third generation cephalosporins are considered by many clinicians to be alternative agents for the treatment of these infections.
Acute Sinusitis
Cefdinir is used in adults and adolescents 13 years of age or older for the treatment of acute maxillary sinusitis caused by susceptible Streptococcus pneumoniae (penicillin-susceptible strains only), Haemophilus influenzae (including b-lactamase-producing strains), or Moraxella (formerly Branhamella) catarrhalis (including b-lactamase-producing strains). While efficacy of cefdinir for the treatment of acute maxillary sinusitis in children 6 months to 12 years of age has not been fully established, use of the drug for the treatment of this infection in pediatric patients is supported by evidence from studies in adults and adolescents, the similar pathophysiology of acute sinusitis in adults and children, and data regarding the pharmacokinetics of cefdinir in children. In controlled studies in patients 13 years of age or older with acute maxillary sinusitis, comparable clinical and bacteriologic responses were obtained with once-daily cefdinir (600 mg once daily), twice-daily cefdinir (300 mg twice daily), or amoxicillin and clavulanate potassium (500 mg of amoxicillin 3 times daily). When patients were subdivided based on the causative organism, the bacterial eradication rate in those with S. pneumoniae or M. catarrhalis infection was 89-100% with either drug; however, in those with H. influenzae infection, the eradication rate was 78% in those who received cefdinir and 57% in those who received amoxicillin and clavulanate potassium.
Community-acquired Pneumonia
Cefdinir is used in adults and adolescents 13 years of age or older for the treatment of mild to moderate community-acquired pneumonia caused by susceptible S. pneumoniae (penicillin-susceptible strains only) or b-lactamase- and non-b-lactamase-producing strains of H. influenzae, H. parainfluenzae, or M. catarrhalis. Cefdinir should not be used in the treatment of pneumonia caused by S. pneumoniae strains that are relatively or completely resistant to penicillins since efficacy of oral cephalosporins in the treatment of these infections has not been established. Limited data in patients with community-acquired pneumonia caused by organisms susceptible to the drugs indicate that the clinical response to cefdinir is similar to that reported with cefaclor, but may be inferior to that reported with amoxicillin and clavulanate potassium. In a double-blind, prospective, randomized study in adults and adolescents 13 years of age or older with community-acquired pneumonia, a satisfactory clinical response (cure plus improvement) was achieved 6-14 days after completion of therapy in 89% of those who received cefdinir (300 mg twice daily for 10 days) and in 86% of those who received cefaclor (500 mg 3 times daily for 10 days). In another study conducted principally in Europe, the clinical cure rate 6-14 days after completion of therapy was 80% in those who received cefdinir (300 mg twice daily for 10 days) and 89% in those who received amoxicillin and clavulanate potassium (500 mg of amoxicillin 3 times daily for 10 days). In these studies, the bacteriologic eradication rate 6-14 days following completion of therapy was 89-92% in those who received cefdinir, 93% in those who received cefaclor, and 93% in those who received amoxicillin and clavulanate potassium. When patients were subdivided based on the causative organism, the presumptive bacteriologic eradication 6-14 days after completion of cefdinir therapy was 95-100% in those with S. pneumoniae infection, 74-85% in those with H. influenzae infection, 91-100% in those with H. parainfluenzae infection, and 100% in those with M. catarrhalis infection.
Acute Otitis Media
Oral cefdinir is used in children 6 months of age or older for the treatment of acute otitis media caused by S. pneumoniae (penicillin-susceptible strains only), H. influenzae (including b-lactamase-producing strains), or M. catarrhalis (including b-lactamase-producing strains). In a controlled study in children 6 months to 12 years of age with acute suppurative otitis media, a 10-day regimen of once-daily cefdinir (14 mg/kg as a single daily dose), twice-daily cefdinir (7 mg/kg twice daily), or amoxicillin and clavulanate potassium (13.3 mg/kg of amoxicillin 3 times daily) produced similar clinical and bacteriologic responses. For additional information regarding treatment of acute otitis media, see Acute Otitis Media under Uses: Otitis Media, in the Cephalosporins General Statement 8:12.06.
Pharyngitis and Tonsillitis
Oral cefdinir is used for the treatment of pharyngitis and tonsillitis caused by susceptible S. pyogenes (group A b-hemolytic streptococci) in adults and children 6 months of age and older. Although cefdinir may effectively eradicate S. pyogenes from the nasopharynx, efficacy of the drug in the subsequent prevention of rheumatic fever has not been fully evaluated to date. In double-blind, controlled studies in adults, adolescents, and children with streptococcal pharyngitis, the clinical and microbiologic response to a 5-day regimen of oral cefdinir was similar to that of a 10-day regimen of oral penicillin V1, 6, 25 whereas the response to a 10-day regimen of cefdinir was superior to that of the 10-day penicillin V regimen. In controlled comparative studies in adults, adolescents, and children, the bacterial eradication rate 4-10 days after completion of therapy was 89-90% in those who received cefdinir for 5 days, 91-94% in those who received cefdinir for 10 days, and 70-83% in those who received penicillin V for 10 days. The clinical cure rate 4-10 days after completion of therapy was about 89-91, 95-97, and 85-90%, respectively. When cefdinir is used in the treatment of pharyngitis and tonsillitis, a once-daily dosing regimen reportedly is as effective as a twice-daily dosing regimen. Selection of an anti-infective agent regimen for the treatment of S. pyogenes pharyngitis and tonsillitis should be based on the drug’s spectrum of activity as well as the regimen’s bacteriologic and clinical efficacy, potential adverse effects, ease of administration and patient compliance, and cost. No regimen has been found to date that effectively eradicates group A b-hemolytic streptococci in 100% of patients. Because penicillin has a narrow spectrum of activity, is inexpensive, and generally is effective, the US Centers for Disease Control and Prevention (CDC), American Academy of Pediatrics (AAP), American Academy of Family Physicians, Infectious Diseases Society of America (IDSA), American Heart Association (AHA), American College of Physicians-American Society of Internal Medicine (ACP-ASIM), and others consider a natural penicillin regimen (i.e., 10 days of oral penicillin V or a single IM dose of penicillin G benzathine) the treatment of choice for streptococcal pharyngitis and tonsillitis and prevention of initial attacks (primary prevention) of rheumatic fever, although oral amoxicillin often is used instead of penicillin V in small children because of a more acceptable taste. Other anti-infectives (e.g., oral cephalosporins, oral macrolides) generally are considered alternatives. There is some evidence that bacteriologic and clinical cure rates reported with 10-day regimens of certain oral cephalosporins (e.g., cefaclor, cefadroxil, cefdinir, cefixime, cefpodoxime proxetil, cefprozil, cefuroxime axetil, ceftibuten, cephalexin) are slightly higher than those reported with the 10-day oral penicillin V regimen. In addition, there is some evidence that a shorter duration of therapy with certain oral cephalosporins (e.g., a 5-day regimen of cefadroxil, cefdinir, cefixime, or cefpodoxime proxetil or a 4- or 5-day regimen of cefuroxime axetil) achieves bacteriologic and clinical cure rates equal to or greater than those achieved with the traditional 10-day oral penicillin V regimen. Based on these results, some clinicians suggest that oral cephalosporins be included as agents of choice for the treatment of S. pyogenes pharyngitis and tonsillitis. However, the IDSA states that first generation cephalosporins can be used for the treatment of pharyngitis in patients hypersensitive to penicillins (except those with immediate-type hypersensitivity to b-lactam anti-infectives) but that cephalosporins appear to offer no advantage over penicillins since they have a broader spectrum of activity and generally are more expensive. In addition, because of limited data to date, the IDSA states that use of cephalosporin regimens administered for 5 days or less for the treatment of S. pyogenes pharyngitis cannot be recommended at this time.
Skin and Skin Structure Infections
Oral cefdinir is used in adults, adolescents, and children 6 months of age or older for the treatment of mild to moderate, uncomplicated skin and skin structure infections caused by S. aureus (including b-lactamase-producing strains) or S. pyogenes. In a comparative study in children 6 months to 12 years of age with mild to moderate bacterial skin and skin structure infections (e.g., impetigo, infecteddermatitis, wound infection, cellulitis, paronychia, abscess), oral cefdinir (7 mg/kg twice daily for 10 days) was as effective as oral cephalexin (10 mg/kg 4 times daily for 10 days). In a comparative study in adults and adolescents 13 years of age or older, oral cefdinir (300 mg twice daily for 10 days) was as effective as oral cephalexin (500 mg 4 times daily for 10 days) for the treatment of bacterial skin and skin structure infections (e.g., abscess, wound infection, paronychia, infected dermatitis, impetigo, cellulitis).
Dosage and Administration
Reconstitution and Administration
Cefdinir is administered orally. The drug may be given without regard to meals. Oral iron preparations, including multivitamin and mineral preparations containing iron, may interfere with the absorption of oral cefdinir resulting in decreased plasma concentrations of the cephalosporin. If concomitant use is necessary, cefdinir doses should be given 2 hours before or after the oral iron preparation. Cefdinir oral suspension can be administered concomitantly with iron-fortified infant formula since concomitant administration with such formula (2.2 mg elemental iron/180 mL) does not alter absorption of the cephalosporin. The effect of iron-fortified food (e.g., iron-fortified breakfast cereal) on oral absorption of cefdinir has not been studied. While concomitant administration of antacids containing aluminum or magnesium interferes with the absorption of oral cefdinir, administration of aluminum- or magnesium-containing antacids 2 hours before or after a dose of cefdinir is not associated with clinically important changes in the pharmacokinetics of the cephalosporin. Therefore, doses of cefdinir should be given 2 hours before or after a dose of aluminum- or magnesium-containing antacid. Cefdinir may be administered as a single daily dose or in divided doses every 12 hours. Once- and twice-daily regimens are similarly effective for the treatment of acute bacterial exacerbations of chronic bronchitis, acute maxillary sinusitis, acute bacterial otitis media, and pharyngitis and tonsillitis caused by susceptible organisms and either regimen may be used in these infections. However, pending further study regarding the efficacy of once-daily cefdinir regimens in the treatment of community-acquired pneumonia and uncomplicated skin and skin structure infections, the manufacturer states that a twice-daily regimen should be used for these infections. Cefdinir powder for oral suspension should be reconstituted at the time of dispensing by adding the amount of water specified on the container to provide a suspension containing 125 mg of cefdinir per 5 mL. The water should be added in 2 equal portions and the bottle inverted and shaken after each addition. Cefdinir oral suspension should be shaken well just prior to administration of each dose.
Dosage
Adult Dosage
Respiratory Tract Infections
For the treatment of acute exacerbations of chronic bronchitis, the usual dosage of cefdinir in adults and adolescents 13 years of age or older is 300 mg every 12 hours for 5-10 days or 600 mg once daily for 10 days. For the treatment of acute maxillary sinusitis in adults and adolescents 13 years of age or older, the usual dosage is 300 mg every 12 hours or 600 mg once daily for 10 days. Adult or adolescents 13 years of age or older should receive cefdinir in a dosage of 300 mg every 12 hours for 10 days for the treatment of community-acquired pneumonia (CAP).
Pharyngitis and Tonsillitis
For the treatment of pharyngitis and tonsillitis, the usual dosage of cefdinir for adults and adolescents 13 years of age or older is 300 mg every 12 hours for 5-10 days or 600 mg once daily for 10 days. (See Uses: Pharyngitis and Tonsillitis.)
Skin and Skin Structure Infections
For the treatment of uncomplicated skin and skin structure infections caused by susceptible bacteria, the usual dosage of cefdinir for adults and adolescents 13 years of age or older is 300 mg every 12 hours for 10 days.
Pediatric Dosage
Children 13 year of age or older or those weighing more than 43 kg may receive the usual adult dosage of cefdinir. Although safety and efficacy of cefdinir in children younger than 6 months of age have not been established, the American Academy of Pediatrics (AAP) states that pediatric patients older than 1 month of age may receive cefdinir in a dosage of 14 mg/kg daily given in 1 or 2 divided doses (maximum 600 mg daily) for the treatment of mild to moderate infections.
Respiratory Tract Infections
The usual dosage of cefdinir for the treatment of acute maxillary sinusitis in children 6 months to 12 years of age is 7 mg/kg every 12 hours or 14 mg/kg once daily for 10 days.
Acute Otitis Media
For the treatment acute bacterial otitis, children 6 months to 12 years of age should receive cefdinir in a dosage of 7 mg/kg every 12 hours for 5-10 days or 14 mg/kg once daily for 10 days.
Pharyngitis and Tonsillitis
For the treatment of pharyngitis and tonsillitis in children 6 months to 12 years of age, the usual dosage of cefdinir is 7 mg/kg every 12 hours for 5-10 days or 14 mg/kg once daily for 10 days. (See Uses: Pharyngitis and Tonsillitis.)
Skin and Skin Structure Infections
For the treatment of mild to moderate, uncomplicated skin and skin structure infections in children 6 months to 12 years of age, the usual dosage of cefdinir is 7 mg/kg every 12 hours for 10 days.
Dosage in Renal and Hepatic Impairment
Patients with creatinine clearances of 30 mL/minute per 1.73 m or greater may receive the usual dosage of cefdinir. The manufacturer recommends that adults with creatinine clearances less than 30 mL/minute per 1.73 m receive cefdinir in a dosage of 300 mg once daily and that children with creatinine clearances less than 30 mL/minute per 1.73 m receive the drug in a dosage of 7 mg/kg (up to 300 mg) once daily. For patients maintained on long-term hemodialysis, the usual initial dosage of cefdinir is 300 mg every 48 hours for adults or 7 mg/kg (up to 300 mg) every 48 hours for children. Because cefdinir is partially removed by hemodialysis, a supplemental dose of cefdinir (300 mg in adults or 7 mg/kg in children) should be given at the end of each dialysis period and subsequent doses administered every 48 hours. While the pharmacokinetics of cefdinir have not been studied in patients with hepatic impairment, hepatic metabolism of the drug is negligible and the manufacturer states that dosage adjustments are not expected to be necessary in such patients.
Cautions
Adverse Effects
Adverse effects reported with cefdinir are similar to those reported with other oral cephalosporins. (See Cautions in the Cephalosporins General Statement 8:12.06.) Cefdinir generally is well tolerated. Diarrhea, the most frequent adverse effect, has been reported in 16% of adult or adolescent patients and in 8% of pediatric patients receiving usual dosages of the drug. Adverse effects usually are transient and mild in severity, but have been severe enough to require discontinuance of the drug in up to 3% of patients.
Precautions and Contraindications
Cefdinir shares the toxic potentials of other cephalosporins, and the usual cautions, precautions, and contraindications associated with cephalosporin therapy should be observed. Prior to initiation of cefdinir therapy, careful inquiry should be made concerning previous hypersensitivity reactions to cephalosporins, penicillins, or other drugs. There is clinical and laboratory evidence of partial cross-allergenicity among cephalosporins and other b-lactam antibiotics, including penicillins and cephamycins. Cefdinir is contraindicated in patients who are hypersensitive to the drug or other cephalosporins and should be used with caution in patients with a history of hypersensitivity to penicillins. Use of cephalosporins should be avoided in patients who have had an immediate-type (anaphylactic) hypersensitivity reaction to penicillins. If an allergic reaction occurs during cefdinir therapy, the drug should be discontinued and the patient treated with appropriate therapy (e.g., epinephrine, corticosteroids, and maintenance of an adequate airway and oxygen) as indicated. Individuals with diabetes mellitus and/or their caregivers should be informed that reconstituted cefdinir oral suspension contains 2.86 g of sucrose per 5 mL. For a more complete discussion of these and other precautions associated with the use of cefdinir, see Cautions: Precautions and Contraindications in the Cephalosporins General Statement 8:12.06.
Pediatric Precautions
Safety and efficacy of cefdinir in neonates and children younger than 6 months of age have not been established. Although adverse effects reported in pediatric patients receiving cefdinir are similar to those reported in adults, the incidence of diarrhea and rash appears to be higher in pediatric patients 2 years of age or younger than in older pediatric patients. Diarrhea has been reported in 17% of those 2 years of age or younger and 4% of those older than 2 years of age. Rash (principally diaper rash in the younger patients) has been reported in 8% of those 2 years of age or younger and 1% of those older than 2 years of age.
Geriatric Precautions
Cefdinir is well tolerated in geriatric patients, and the incidence of adverse effects (including diarrhea) reported in clinical trials generally has been lower in geriatric patients than in younger adults. Although single-dose studies indicate that peak plasma concentrations and the area under the plasma-concentration time curve (AUC) of cefdinir may be higher in older adults than in younger adults, no adjustments in cefdinir dosage appear to be necessary other than those related to renal impairment. (See Dosage and Administration: Dosage in Renal and Hepatic Impairment.)
Mutagenicity and Carcinogenicity
In vivo and in vitro studies evaluating cefdinir have not shown evidence of mutagenicity. Studies have not been performed to evaluate the carcinogenic potential of the drug.
Pregnancy, Fertitlity and Lactation
Reproduction studies in rats or rabbits using oral cefdinir in dosages 70 or 0.7 times, respectively, the usual human dosage (based on mg/kg daily) have not revealed evidence of teratogenicity. There are no adequate and controlled studies using cefdinir in pregnant women or during labor and delivery, and the drug should be used during pregnancy only when clearly needed. Studies in rats using oral cefdinir in dosages up to 70 times the usual human dosage (based on mg/kg daily) have not revealed evidence of impaired fertility. Cefdinir was not detected in human milk following a single 600-mg oral dose of the drug. However, the drug should be used with caution in nursing women. Spectrum Based on its spectrum of activity, cefdinir is classified as a third generation cephalosporin. For information on the classification of cephalosporins and closely related b-lactam antibiotics based on spectra of activity, see Spectrum in the Cephalosporins General Statement 8:12.06. Cefdinir is stable in the presence of a wide variety of b-lactamases produced by gram-negative and gram-positive bacteria but may be hydrolyzed by certain plasmid-mediated extended-spectrum b-lactamases. Like other currently available oral third generation cephalosporins (e.g., cefpodoxime proxetil, ceftibuten), cefdinir has an expanded spectrum of activity against aerobic gram-negative bacteria compared with first and second generation cephalosporins but is inactive against most strains of Enterobacter and Pseudomonas aeruginosa. In vitro on a weight basis, cefdinir is more active against susceptible staphylococci and streptococci than other currently available oral third generation cephalosporins (e.g., cefpodoxime proxetil, ceftibuten). Cefdinir is inactive against enterococci (e.g., Enterococcus faecalis [formerly Streptococcus faecalis]) and methicillin-resistant staphylococci.
Pharmacokinetics
Cefdinir exhibits nonlinear dose-dependent pharmacokinetics. The pharmacokinetics of cefdinir have been studied in adults and in pediatric patients 6 months to 12 years of age. There is no evidence of gender- or race-related differences in the pharmacokinetics of the drug. Studies in adults with impaired renal function indicate that the pharmacokinetics of cefdinir are affected by the degree of renal impairment and that decreases in elimination rate, apparent oral clearance, and renal clearance are approximately proportional to reductions in creatinine clearance. Differences in the pharmacokinetics of the drug in geriatric individuals appear to be related to changes in renal function rather than age. Pharmacokinetics of cefdinir have not been studied in patients with hepatic impairment.
Absorption
Following oral administration of cefdinir capsules or oral suspension, peak plasma concentrations are attained 2-4 hours after the dose. Relative bioavailability of cefdinir administered to adults as the commercially available oral suspension is 120% of that achieved following administration of commercially available capsules of the drug. When administered as capsules, estimated oral bioavailability of cefdinir is 21% following a 300-mg dose and 16% following a 600-mg dose; estimated absolute bioavailability is 25% following administration of the oral suspension. In healthy adults who received a single 300- or 600-mg oral dose of cefdinir as capsules, peak plasma concentrations about 3 hours after the dose were 1.6 or 2.87 mcg/mL, respectively. Results of a study in adults 19-91 years of age given a single 300-mg oral dose of cefdinir indicate that peak plasma concentrations may be 44% higher and the area under the plasma concentration-time curve (AUC) 86% higher in older adults compared with younger adults. In pediatric patients 6 months to 12 years of age who received a single 7-mg/kg oral dose of cefdinir as the suspension, peak plasma concentrations were attained 2.2 hours after the dose and averaged 2.3 mcg/mL. Single 14-mg/kg oral doses in these patients resulted in peak plasma concentrations averaging 3.86 mcg/mL at 1.8 hours after the dose. Compared with administration in the fasting state, concomitant administration with a high-fat meal decreases the rate and extent of absorption of oral cefdinir by 16 and 10%, respectively. There is no evidence that cefdinir accumulates in plasma following multiple doses in patients with normal renal function receiving the drug once or twice daily.
Distribution
The volume of distribution of cefdinir averages 0.35 L/kg in adults and 0.67 L/kg in children 6 months to 12 years of age. Following oral administration, cefdinir is distributed into blister fluid, middle ear fluid, tonsils, sinus tissue, and bronchial mucosa and epithelial lining fluid in concentrations ranging from 15-48% of concurrent plasma concentrations. In adults undergoing elective tonsillectomy who received single 300- or 600-mg oral doses of cefdinir, median concentrations of the drug in tonsils 4 hours after the dose were 0.25 or 0.36 mcg/g, respectively. In adults undergoing elective maxillary and ethmoid sinus surgery, median sinus tissue concentrations 4 hours after single 300- or 600-mg oral doses of the drug were less than 0.12 or 0.21 mcg/g, respectively. In adults undergoing diagnostic bronchoscopy who received single 300- or 600-mg oral doses of cefdinir, median bronchial mucosa concentrations 4 hours after the dose were 0.78 or 1.14 mcg/mL, respectively, and median epithelial lining fluid concentrations were 0.29 or 0.49 mcg/mL, respectively. In pediatric patients with acute bacterial otitis media who received single 7- or 14-mg/kg oral doses of cefdinir, median concentrations of the drug in middle ear fluid 3 hours after the dose were 0.21 or 0.72 mcg/mL, respectively. Median maximal concentrations of cefdinir in blister fluid 4-5 hours after single 300- or 600-mg oral doses of the drug were 0.65 or 1.1 mcg/mL, respectively. It is not known whether cefdinir is distributed into CSF following oral administration. Cefdinir was not detected in human milk following oral administration of single 600-mg doses of the drug. Cefdinir is 60-70% bound to plasma proteins in adults or children; binding is independent of drug concentration.
Elimination
Cefdinir is not appreciably metabolized. The drug is eliminated principally by renal excretion. In adults with normal renal function, the mean plasma elimination half-life of cefdinir is 1.7-1. hours and renal clearance is 2 mL/minute per kg. Following oral administration of 300- or 600-mg of cefdinir, apparent oral clearance is 11.6 or 15.5 mL/minute per kg, respectively, and 18. or 11.% of the dose, respectively, is eliminated unchanged in urine. Clearance of cefdinir is decreased in patients with impaired renal function. In patients with creatinine clearances of 30-60 mL/minute, peak plasma concentrations and plasma elimination half-life of the drug are increased approximately twofold and the AUC is increased approximately threefold. In patients with creatinine clearances less than 30 mL/minute, peak plasma concentrations are increased approximately twofold but plasma elimination half-life and AUC are increased approximately fivefold and sixfold, respectively. Cefdinir is removed by hemodialysis. A 4-hour period of dialysis removes approximately 63% of the drug and decreases the apparent elimination half-life of cefdinir in patients with substantial renal impairment from 16 to 3.2 hours.
Chemistry and Stability
Chemistry
Cefdinir is a semisynthetic cephalosporin antibiotic. The drug is an oral aminothiazolyl hydroxyimino cephalosporin. Cefdinir is structurally similar to other oral (cefpodoxime proxetil, ceftibuten) or parenteral (cefepime, cefotaxime, ceftazidime, ceftizoxime, ceftriaxone) cephalosporins that contain an aminothiazolyl side chain at position 7 of the cephalosporin nucleus; however, cefdinir contains an unsubstituted oxime group rather than the methoxyimino group contained in many aminothiazolyl cephalosporins. The oxime group may contribute to improved activity against gram-positive bacteria. Like cefixime, cefdinir contains a vinyl moiety at position 3 of the cephalosporin nucleus which makes the drug suitable for oral administration. Cefdinir occurs as a white to slightly brownish-yellow solid and has solubilities of 0.46 mg/mL in water and 0.19 mg/mL in methanol. Commercially available cefdinir powder for oral suspension occurs as a cream-colored, strawberry-flavored powder. Following reconstitution, the cream-colored oral suspension contains 125 mg of cefdinir per 5 mL1 and has a pH of 3.5-4.5.
Stability
Cefdinir capsules and powder for oral suspension should be stored at 25°C, but may be exposed to temperatures ranging from 15-30°C. Following reconstitution, cefdinir oral suspension should be stored in a tight container and is stable for 10 days at 15-30°C; any unused suspension should be discarded after this period. For further information on chemistry, mechanism of action, spectrum, resistance, uses, cautions, acute toxicity, drug interactions, or laboratory test interferences of cefdinir, see the Cephalosporins General Statement 8:12.06.
Preparations
Cefdinir Oral Capsules 300 mg Omnicef®, Abbott For suspension 125 mg/5 mL Omnicef®, Abbott
Prescription
In many countries, Omnicef is available over the counter, which means you can buy it without a prescription.