他院で、連鎖球菌による扁桃炎、咽頭炎の抗菌薬治療に失敗した19歳 既往歴なしの患者さんが入院しました。入院時に咽頭痛が強く声が出ない。またspike fever あり。
なお、主治医にPCG 2400 or ABPC注射 8g 10日間 (途中明らかに良好ならば、サワシリン内服へ変更) を提案し、ABPCとなりました。
Antibiotic failure in the treatment of streptococcal tonsillopharyngitis
Factors associated with antibiotic failure in the treatment of streptococcal tonsillopharyngitis include epidemiologic factors, clinical factors, and microbiologic factors.
Epidemiologic factors include crowded conditions that facilitate group A streptococcal (GAS) transmission in households, workplaces, schools, and daycare centers.
Clinical factors include patient age, duration of illness prior to treatment, antibiotic formulation, and patient adherence. Clinical response to treatment is highest among adolescents and adults. Early treatment may suppress development of immunity, and treatment success may be inversely correlated with the duration of illness prior to the initiation of therapy.
In some countries outside the United States, benzathine penicillin G preparations that produce a lower, shorter, variable duration of serum concentrations have been described; use of such preparations may contribute to antibiotic failure in some cases． This has not been described as a problem in the United States.
Antibiotic failure associated with shorter duration of antibiotic therapy (3 to 6 days compared with standard duration of 10 days) was evaluated in a systematic review including 20 studies with more than 13,000 cases of acute GAS pharyngitis． The studies evaluating shorter duration of treatment noted shorter duration of symptoms including fever and throat soreness as well as lower risk of early clinical treatment failure (odds ratio [OR] 0.80, 95% CI 0.67-0.94), but no significant difference in early bacteriological treatment failure or late clinical recurrence compared with standard duration treatment. However, the overall risk of late bacteriological recurrence was worse in the shorter duration treatment studies (OR 1.31, 95% CI 1.16-1.48). There was no significant difference in the rate of long-term complications (glomerulonephritis or acute rheumatic fever) between patients who received shorter versus longer duration of therapy.
Microbiologic factors include presence of copathogens, alteration of microbial ecology, coaggregation, and streptococcal carriage. GAS carriage is likely in the setting of GAS detection in the throat but absence of tonsillopharyngitis symptoms or demonstrable rise in streptococcal antibody titers.
It can be difficult to distinguish between GAS tonsillopharyngitis and acute viral pharyngitis in a patient with GAS carriage. The possibility of GAS carriage should be considered in patients with multiple culture-positive (or rapid test–positive) episodes of pharyngitis, particularly in the setting of atypical symptoms (eg, prolonged course and/or association with viral symptoms such as cough and rhinorrhea). Such patients should also have a positive throat culture (or rapid test) when asymptomatic.