Commentary
6 steps to take when a patient insists on that antibiotic
Patients may be less likely to ask for an antibiotic if you refer to acute bronchitis as a "chest cold."
Any use of antibiotics can promote the development of drug resistance, but antibiotic misuse is far more likely to lead to superinfections, allergic reactions, and adverse events. These are pressing concerns in ambulatory care, as well as in inpatient settings, but efforts to address unnecessary and inappropriate use of antibiotics have been more focused on the latter.1
A US study published in 2013 found that, in one year alone, nearly 260 million courses of antibiotics were prescribed to patients in ambulatory care. Patients <2 years or >65 years of age had the highest antibiotic prescription rates, and practitioners in family medicine were the most likely to prescribe them.2 Yet evidence suggests that more than half of all community-based antibiotic prescriptions may be unnecessary or inappropriate—the combined result of patient, physician, and health system factors.3 The continuing shift of medical services from acute care to community-based settings has contributed to an increase in antibiotic-resistant infections in the community, as well.
Skin infections caused by Staphylococcus aureus, respiratory infections caused by Streptococcus pneumoniae, urinary tract infections (UTIs) caused by Escherichia coli and other Enterobacteriaceae, and sexually transmitted diseases such as gonorrhea are recent examples of community-transmitted infections for which increases in antibiotic resistance rates have been reported.4 It is crucial for primary care physicians to know when watchful waiting is appropriate, when antibiotics are indicated, and, when needed, which antimicrobials are most likely to be effective. The case studies, text, and tables that follow can be used as a guide.
Pictured: Colorized scanning electron micrograph of a neutrophil (purple) ingesting methicillin-resistant Staphylococcus aureus bacteria (green).
CASE 1 ›
Ear tugging, fever, and upper respiratory symptoms
Two-year-old Daniel is brought in to see his family physician. His mother reports that he has been tugging at his right ear for the past 24 hours. Daniel also has upper respiratory symptoms and an axial temperature of 101.9°F. He had one episode of vomiting, which kept him out of day care today. The patient’s past medical history is significant for surgery to repair an atrial septal defect 15 months ago.
Daniel takes no medication, has no drug allergies, and his immunizations are up to date. He was given a course of antibiotics to treat otitis media 2 months ago. A physical exam reveals an irritable but normally developing child. An otoscopic exam reveals reddened tympanic membranes bilaterally with normal mobility.
CASE 2 ›
Dysuria and urethral discharge
Twenty-year-old Jon F visits his FP and reports painful urination and purulent urethral discharge of 3 days’ duration. He denies having flank pain. When asked about his sexual history, Mr. F acknowledges having had unprotected intercourse with a sex worker less than 2 weeks ago.
The patient’s past medical history is unremarkable. He reports smoking marijuana occasionally, but denies other recreational drug use.
He tested negative for human immunodeficiency virus (HIV) 18 months ago, but says he has used condoms inconsistently since then. A physical exam reveals normal vital signs, with no sores or rashes. His chest, heart, musculoskeletal, abdominal, and rectal exams are normal. A genital exam reveals a normal circumcised penis, with reddened meatus and purulent discharge; the scrotum and testes are normal and without lesions, tenderness, or masses.
If Daniel and Jon F were your patients, would you prescribe antibiotics for them—and if so, what drugs would you select?
How to manage community-acquired MRSA
Methicillin-resistant S aureus (MRSA) is a common antimicrobial-resistant pathogen found in health care settings and in the community. While most community-acquired infections are minor and involve the skin and soft tissues, community-acquired (CA)-MRSA can cause pneumonia, thrombophlebitis, and necrotizing fasciitis.5
Identifying patients at risk
Individuals who share personal items, such as toothbrushes or razors, or have physical contact with anyone who is infected with or who carries the multidrug-resistant pathogen (eg, those spending time in crowded spaces like prisons, schools, or day care centers) are at increased risk for CA-MRSA. So, too, are intravenous (IV) drug users, men who have sex with men, individuals who have repeated skin trauma or contact with animals, and those of Native American, African-American, and Pacific Islander descent.5
MRSA resistance mechanisms include expression of altered penicillin-binding proteins, which have a reduced affinity for beta-lactam antibiotics. MRSA isolates may also be resistant to macrolides, aminoglycosides, fluoroquinolones, and clindamycin. CA-MRSA is not typically associated with the same degree of multidrug resistance as hospital-acquired strains. Instead, CA-MRSA usually produces a toxin known as Panton-Valentine leukocidin (PVL), which leads to leukocyte destruction and local tissue necrosis.6
Uncomplicated CA-MRSA skin and soft-tissue infections usually respond to incision and drainage, provided the patient (or parent) is instructed in and adheres to the recommended hygiene and wound care provisions. Antimicrobial agents are generally reserved for patients who have extensive disease involving multiple infection sites and/or systemic symptoms, purulent cellulitis without drainable foci, or septic phlebitis, or failed to respond to incision and drainage alone. Extreme age is a reasonable indication for antibiotics as well. Patients with more serious conditions, such as pneumonia, thrombophlebitis, or necrotizing fasciitis, require high acuity care and IV antibiotics.7
First-line empiric therapy in the outpatient setting should be either trimethoprim/sulfamethoxazole (TMP/SMX) or a long-acting tetracycline (TABLE 1).7 The ideal adult dose of TMP/SMX is 2 double-strength tablets (160/800 mg) twice daily for 5 to 10 days, as treatment failures are more prevalent with lower doses. Tetracyclines should be avoided in patients younger than 8 years.7
Clindamycin is an option in settings in which isolates can be tested to ensure a lack of inducible resistance; it is also the preferred agent for pregnant women.7 Topical mupirocin may be suitable for children with minor skin infections or secondarily infected skin lesions. Oral linezolid and tedizolid can also be used to treat CA-MRSA, but cost and the potential for drug interaction may prohibit their use. Linezolid inhibits PVL toxin production, however, and may be useful in more serious infections, such as necrotizing fasciitis.7
Strategies for preventing recurrent infection include personal and environmental hygiene measures for patients and close contacts. Decolonization strategies such as application of intranasal mupirocin 2% and washing with chlorhexidine soap may also be considered.7