The FDA has approved omadacycline (Nuzyra – Paratek), a semisynthetic tetracycline derivative, for once-daily IV and oral treatment of community-acquired bacterial pneumonia (CAP) and acute bacterial skin and skin structure infections (ABSSSIs) in adults.

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

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 approved oritavancin (Orbactiv – The Medicines Company), a long-acting lipoglycopeptide antibiotic given as a single intravenous (IV) dose, for treatment of acute bacterial skin and skin structure infections caused by susceptible gram-positive bacteria in adults. It is the third lipoglycopeptide antibiotic to be marketed in the US; telavancin (Vibativ) and dalbavancin (Dalvance) were approved earlier.

The FDA has approved two new drugs for treatment of adults with acute bacterial skin and skin structure infections caused by susceptible gram-positive bacteria. Dalbavancin (Dalvance – Durata) is a long-acting intravenous (IV) lipoglycopeptide antibiotic similar to telavancin (Vibativ). Tedizolid phosphate (Sivextro – Cubist) is an IV and oral oxazolidinone antibacterial drug similar to linezolid (Zyvox). A third IV antibiotic, oritavancin (Orbactiv), recently approved by the FDA for the same indication, will be reviewed in a future issue.

Methicillin-resistant Staphylococcus aureus (MRSA), which was traditionally a nosocomially-acquired organism but now frequently occurs in the absence of healthcare exposure, is the predominant cause of suppurative skin and soft-tissue infections in many parts of the US. Community-associated MRSA usually causes furunculosis, purulent cellulitis, and abscesses, but necrotizing fasciitis, necrotizing pneumonia, and sepsis can also occur.

The FDA has approved levomilnacipran (lee" voe mil na' si pran; Fetzima – Forest), a serotonin and norepinephrine reuptake inhibitor (SNRI), for treatment of major depressive disorder. Levomilnacipran is the more active enantiomer of milnacipran (Savella), which was approved in 2009 for management of fibromyalgia. Fetzima has not been studied in fibromyalgia.

The text that follows reviews some common bacterial infections and their empiric treatment pending the results of culture and susceptibility testing. The recommendations made here are based on the results of susceptibility studies, clinical trials, and the opinions of Medical Letter reviewers. Tables 1 and 2 list the usual dosages of antibacterial drugs.

Tuberculosis (TB) is still a common cause of death worldwide, and the prevalence of drug-resistant TB poses challenges to its treatment and control. Guidelines with detailed management recommendations are available from the American Thoracic Society, Centers for Disease Control and Prevention (CDC) and Infectious Diseases Society of America (IDSA).

Attention-deficit/hyperactivity disorder (ADHD) is a disruptive behavior disorder that occurs in about 5% of school-age children, most often in boys, and frequently persists into young adulthood.

The FDA has approved ceftaroline fosamil (Teflaro – Forest), an intravenous (IV) cephalosporin, for treatment of acute bacterial skin and skin structure infections, including those caused by methicillin-resistant Staphylococcus aureus (MRSA), and for treatment of community-acquired bacterial pneumonia in adults. It is the first beta-lactam antibiotic approved for treatment of MRSA.

Drugs are not the only treatment for mood disorders. Psychotherapy remains an important component in the management of these disorders, and electroconvulsive therapy (ECT) has a long history of efficacy and safety when drugs are ineffective, poorly tolerated or cannot be used. Some drugs are recommended here for indications that have not been approved by the FDA.

Telavancin (Vibativ - Astellas and Theravance), a lipoglycopeptide derivative of vancomycin (Vancocin, and others), has received FDA approval for treatment of complicated skin and skin structure infections caused by susceptible gram-positive bacteria in adults.

The recent Medical Letter article on vancomycin dosing and monitoring briefly mentioned use of an alternative antibiotic for treatment of methicillin-resistant Staphylococcus aureus (MRSA) with reduced susceptibility to vancomycin. Some readers have asked for more information on this subject.

Click here to view the free full article.

(Med Lett Drugs Ther 2009; 51:25) In the paragraph on dosing, the second-to-last sentence should have said that the new recommendations suggest considering use of an alternative antibiotic when the MIC for the infecting organism is ≥2 mg/L, not >2 mg/L.

Consensus recommendations for dosing and therapeutic monitoring of intravenous (IV) vancomycin (Vancocin, and others) were recently published. IV vancomycin has been used for decades as an alternative to penicillins for treatment of serious infections due to gram-positive cocci. In recent years, the widest use of the drug has been for treatment of serious methicillin-resistant Staphylococcus aureus (MRSA) infections.

Information about empirical treatment of bacterial infections, emerging trends in antimicrobial resistance, new drugs and new data about older drugs continue to become available. Usual pathogens and empiric treatment for some common types of infections are summarized in the text and a table listing the drugs of choice and alternatives for each pathogen begins on page 40. The recommendations made here are based on the results of susceptibility studies, clinical trials and the opinions of Medical Letter consultants.

Methicillin-resistant Staphylococcus aureus (MRSA) infections, which have been a concern for many years, previously occurred primarily in hospitalized patients and those recently treated with antibiotics. In the past few years, there has been an increasing incidence worldwide of community-associated (CA) MRSA infections in patients without recent antibiotic exposure or contact with the healthcare system.

Tigecycline (Tygacil - Wyeth), a derivative of minocycline, is a new intravenous (IV) antibiotic approved for treatment of complicated intra-abdominal and skin and skin-structure infections.

New drugs for bacterial infections and new information about older drugs continue to become available. Empirical treatment of some common bacterial infections is discussed in this article. A table listing the drugs of choice and alternatives for each pathogen begins on page 18. These recommendations are based on results of susceptibility studies, clinical trials and the opinions of Medical Letter consultants. Local resistance patterns should be taken into account. Trade names are listed on page 24.

Daptomycin (Cubicin - Cubist), a cyclic lipopeptide (a new class of antibiotics), has been approved by the FDA for intravenous (IV) treatment of complicated skin and skin structure infections. It is being promoted as a once-daily bactericidal alternative to vancomycin (Vancocin, and others) for methicillin-resistant Staphylococcus aureusinfections.

Five different selective serotonin reuptake inhibitors (SSRIs) are promoted for treatment of depression and a sixth (fluvoxamine) for use in obsessive compulsive disorder. Which one should we prescribe for our patients?

The choice of drugs for treatment of pneumonia depends on the most likely pathogens causing the infection and local antimicrobial resistance patterns. Factors such as severity of illness, presence of co-morbid conditions and whether the infection is community or hospital-acquired also need to be considered.

Linezolid, the first of a new class of antibiotics, the oxazolidinones, has been marketed for treatment of infection due to vancomycin-resistant Enterococcus faecium, nosocomial and community-acquired pueumonia due to Staphylococcus aureus or penicillin-sucsceptible Streptococcus pneumoniae, and skin and skin structure infections, including those due to methicillin-resistant S. aureus (MRSA).

Since The Medical Letter last reviewed the choice of drugs for treatment of bacterial infections, a few new drugs and some new information about older drugs have become available.