The FDA has warned that use of the macrolide antibiotic clarithromycin (Biaxin, and generics) may increase the risk of cardiovascular morbidity and mortality in patients with heart disease.

About 50% of the world’s population is infected with Helicobacter pylori. These gastric bacteria can cause chronic inflammation and have been associated with development of gastritis, peptic ulcer disease, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Eradication of H. pylori can promote gastric healing, prevent recurrence of duodenal and gastric ulcers, and reduce the incidence of gastric cancer. Guidelines for treatment of H. pylori infection were updated recently.

Antimicrobial prophylaxis can decrease the incidence of postoperative surgical site infection after some procedures. Since the last Medical Letter article on this subject, consensus guidelines have been published. Recommendations for prophylaxis in specific surgical procedures are listed in Table 1.

The FDA has approved a fixed-dose combination of meropenem, a carbapenem antibiotic, and vaborbactam, a new beta-lactamase inhibitor (Vabomere – Melinta), for IV treatment of adults with complicated urinary tract infections (UTIs) that are proven or strongly suspected to be caused by Escherichia coli, Klebsiella pneumoniae, or Enterobacter cloacae spp. complex. Meropenem (Merrem, and generics) has been approved for years for treatment of complicated skin and skin structure infections, intra-abdominal infections, and bacterial meningitis. Resistance to meropenem and other...

Flosequinan (Manoplax - Boots), a fluoroquinolone derivative, is now available in the USA for treatment of congestive heart failure. Labeling approved by the US Food and Drug Administration recommends the drug only for patients who cannot tolerate or have not responded adequately to an angiotensin-converting enzyme (ACE) inhibitor.

Doripenem (Doribax - Ortho-McNeil Janssen), an intravenous (IV) carbapenem antibiotic with a spectrum of activity similar to that of imipenem and meropenem, has been approved by the FDA for treatment of complicated intra-abdominal and urinary tract infections. Use of doripenem for treatment of nosocomial pneumonia, including ventilator-associated pneumonia, is still under FDA review.

View the Comparison Table: Some Antibiotics for MRSA Skin and Skin Structure Infections

This article includes recommendations for management of most sexually transmitted infections (STIs) other than HIV and viral hepatitis. Some of the indications and dosages recommended here have not been approved by the FDA (see Table 1).

Rifaximin (Xifaxan - Salix), a non-absorbed oral antibiotic derived from rifampin (Rifadin, and others), has been approved by the FDA for treatment of travelers' diarrhea caused by noninvasive strains of Escherichia coli in patients 12 years of age or older. It has been available in Europe since 1987.

The FDA has approved fidaxomicin (Dificid – Optimer), a new oral macrolide antibiotic, for treatment of Clostridium difficile-associated diarrhea in patients ≥18 years old. The incidence and severity of C. difficile infection (CDI) have increased in recent years with the emergence of an epidemic hypervirulent strain (NAP1/B1/027), possibly related to widespread use of fluoroquinolones.