More antibiotics are prescribed for treatment of acute otitis media (AOM) than for any other infection in young children. Children with AOM typically present with otalgia, fever, and bulging and erythema of the tympanic membrane.

Treatment of community-acquired pneumonia (CAP) is usually empiric, with selected antibiotic regimens directed against some of the most common causative pathogens. Recommended empiric regimens are listed in Table 2; recommended antibiotic dosages for treatment of CAP are listed in Tables 3 and 4. Joint guidelines for treatment of CAP by the American Thoracic Society and the Infectious Diseases Society of America (ATS/IDSA) were updated in 2019.

Bacterial infections in adults are generally treated empirically, with the antibiotic covering most, but not all, of the potential causative pathogens. For some infections, culture and sensitivity testing can guide treatment, allowing for use of narrower-spectrum antibiotics. The recommended dosages and durations of antibiotic treatment for common respiratory, skin, and urinary tract infections are listed in Tables 1-3. Infectious disease experts now recommend shorter treatment durations for many infections to reduce the development of antimicrobial resistance and minimize adverse effects.

The FDA has announced that it is requiring changes in the labeling of systemic fluoroquinolones to warn that the risk of serious adverse effects, including tendinitis, peripheral neuropathy and CNS effects, generally outweighs their benefit for the treatment of acute sinusitis, acute exacerbations of chronic bronchitis, and uncomplicated urinary tract infections. For these infections, the new labels will recommend reserving fluoroquinolones for patients with no other treatment options.

The most recent guidelines from the Infectious Diseases Society of America (IDSA) and its European counterpart on the choice of antimicrobials for treatment of uncomplicated urinary tract infections (UTIs) in non-pregnant women focus on the unnecessary use of fluoroquinolones to treat uropathogens that are increasingly becoming resistant to them. Resistance of Escherichia coli to ciprofloxacin in the US has increased from 3% in 2000 to 17.1% in 2010.

Readers have asked us to update our 2004 article on tablet splitting. Breaking drug tablets in half is a common practice, but the FDA recently advised consumers against it (FDA Consumer Health Information, July 2009).

Lyme disease in North America is caused by the spirochete Borrelia burgdorferi, which is transmitted to humans by Ixodes scapularis or pacificus ticks. These ticks may also carry other pathogens; coinfection with Babesia microti or Anaplasma phagocytophilum (formerly Ehrlichia) has been reported.1 In 2001 and 2002, 12 states (CT, DE, ME, MD, MA, MI, NH, NJ, NY, PA, RI, WI) reported about 95% of all the Lyme disease in the US, but cases occurred in all states except HI, MT and OK. Most Lyme disease in North America occurs between May and September.