Looking for data.
In the article "For AOM, Cefdinir Equals Amoxicillin/Clavulanate," Dr. Stan L. Block alluded to the fact that there are studies showing that once-daily Omnicef for 10 days is more effective than b.i.d, dosing for 5 days (February 2004, p. 20).
I am only aware of one study that looked at the two side by side (along with Augmentin 45 mg/kg divided t.i.d.) and held they were fairly similar in efficacy.
Are there other data to support the continued use of Omnicef as a once-daily drug versus the 5-day, b.i.d, course?
Gary Schlichter, M.D.
Dr. Block replies:
I appreciate Dr. Schlichter's comments and the opportunity to clarify some of the highlights of our earlier paper (Pediatr. Infect. Dis. J. 19[12 Supp1.]:S159-65, 2000.
In that study, we actually compared 10 days of cefdinir 14 mg/kg per day, either as a single dose or divided twice daily, with 10 days of amoxicillin-clavulanate 40 mg/10 mg per kg per day divided thrice daily (the old formulation and dosing schedule).
Although Dr. Schlichter is correct in that no differences were observed in overall outcomes for each of the three groups (83%, 80%, and 86%, respectively), statistically significant differences in efficacy were noted in two subpopulations of patients.
We observed that twice-daily dosing was less efficacious than both once-daily cefdinir and amoxicillin-clavulanate for children younger than 24 months (63% vs. 80% and 89%, respectively) and for those who had pneumococcus recovered from tympanocentesis (55% vs. 80% and 90%, respectively).
The rates of gastrointestinal adverse effects were nearly threefold higher for the old amoxicillin-clavulanate dosing regimen.
Thus, when prescribing cefdinir, I would recommend that clinicians use the single dose of 14 mg/kg per day of cefdinir for 10 days in younger children and in those who are recent antibiotic failures.
The twice-daily dosing for a short course is reasonable for children older than 2 years with uncomplicated AOM, in whom it also will be a more cost-effective option.
Our latest paper reflects that, among children who have received 7-valent pneumococcal conjugate vaccine (PCV7), even a shorter course of twice-daily cefdinir is slightly more effective than the standard dose (45 mg/6.4 mg per kg per day) of amoxicillin-clavulanate twice a day.
This was the only formulation available when the study was performed. It could be that the higher dose (90 mg/6.4 mg per kg per day) of amoxicillin-clavulanate would perform better.
This finding may also be related to the major microbiologic shift towards more Haemophilus influenzae organisms in PCV7 vaccinated children.
The latest American Academy of Pediatrics American Academy of Family Physicians guidelines for AOM may be too restrictive regarding antibiotic choices for PCV7-vaccinated children who have failed high-dose amoxicillin. A
Although amoxicillin-clavulanate is an excellent drug for AOM, the addition of clavulanate to amoxicillin provides additional coverage only for [beta]-lactamase-producing gram-negative organisms in highdose amoxicillin failures. Oral third-generation cephalosporins provide superb coverage for all gram-negative organisms in AOM, whether [beta]-lactamase producing or not.