Description of Medical Condition Inflammation of the bronchioles, usually seen in young children, occasionally in high-risk adults. May be seasonal (winter and spring) and often occurs in epidemics. Usual course: insidious; acute; progressive. System(s) affected: Pulmonary Genetics: N/A Incidence/Prevalence in USA: Medical care provided to 1000-1500/100,000 annually. Estimated incidence is higher. Annual winter-spring epidemics. Predominant age: newborn-2 years (peak age 2-6 months) Predominant sex: Male > Female Medical Symptoms and Signs of Disease Anorexia Cough Cyanosis Expiratory wheezing Apnea Fever Grunting Inspiratory crackles Intercostal retractions Irritability Noisy breathing Otitis media Pharyngitis Tachycardia Tachypnea Vomiting What Causes Disease? Respiratory syncytial virus — most prevalent Parainfluenza Adenovirus Rhinovirus Influenza virus Chlamydia Eye, nose, […]


Description of Medical Condition Disease caused by a ubiquitous mold that primarily involves the lungs. Disease frequently lethal in neutropenic and bone marrow transplant (BMT) patients. Syndromes include: Allergic aspergillosis Extrinsic allergic alveolitis — hypersensitivity pneumonitis in individuals repeatedly exposed to the fungus Allergic bronchopulmonary aspergillosis (ABPA) pulmonary infiltrates, mucous plugging; secondary to allergic reaction to fungus Aspergillomas: "fungus ball" saprophytic colonization within pre-existing pulmonary cavities Invasive aspergillosis: most common and severe in BMT and neutropenic patients. Also occurs with increased frequency in other immunocompromised persons, such as those with AIDS, solid organ transplant or high dose corticosteroids; commonly fatal. System(s) affected: Pulmonary, Nervous, Gastrointestinal, Musculoskeletal, Cardiovascular Genetics: No known genetic […]


Gemifloxacin (LG Life Sciences [a spin-off of LG Chemical]/Oscient's [formerly Genesoft/Genome Therapeutics] Factive) is the newest fluoroquinolone to enter the U.S. market. The oral product was launched in September 2004 for the treatment of mild to moderate acute exacerbations of chronic bronchitis and community-acquired pneumonia (community-acquired pneumonia). An IV form is also in development. The drug was formerly being developed by SmithKline Beecham (now GlaxoSmithKline [GSK]). SmithKline Beecham submitted a new drug application (NDA) in December 1999 for the treatment of bacterial respiratory and urinary tract infections, including community-acquired pneumonia, chronic bronchitis, and acute sinusitis. However, the FDA issued a nonapprovable letter in 2000, citing insufficient safety data about gemifloxacin's effect […]

Acute Exacerbations of Chronic Bronchitis: Emerging therapies

Despite the large patient populations with respiratory tract infections (RTIs), in recent years, many biopharmaceutical companies have shifted development effort away from RTIs to pursue other disease areas with perceived higher unmet need (e.g., resistant hospital-acquired infections). Likewise, many companies have shifted away from antibacterial drug development in favor of chronic disease markets perceived to have higher return on investment. The reasons behind the move away from antibiotics include a perceived high level of competition, relatively low unmet need, and relatively high development costs and large clinical trials required for approval of community-based antibiotics. As a result, the pipeline of emerging antibacterial agents, particularly for RTIs, has dwindled. Virtually all of […]

Ketolides: Cethromycin

Overview Ketolides are a new class of antibacterials specially designed to combat respiratory tract pathogens that have acquired resistance to macrolides. The ketolides are derivatives of the macrolide erythromycin A. Telithromycin (Sanofi-Aventis' s Ketek) is the first and only member of this new class to be approved for clinical use. The ketolides exhibit good activity against gram-positive and some gram-negative organisms, but their main advantage is their excellent activity against erythromycin-resistant S. pneumoniae. Resistance to existing macrolide antibiotics creates an important commercial opportunity for entry of the "next-generation" macrolide antibiotics. Macrolides are currently a preferred class of antibacterials for first-line treatment of RTIs because of their spectrum of activity and ease […]


Overview Streptogramins are produced by streptomycetes and are classified as A or B compounds, based on their mechanism of action as outlined below. As a class, streptogramin A and B compounds are bacteriostatic when used separately. However, when used in combination, they can act in synergy to become bactericidal. They are active primarily against gram-positive bacteria. Streptogramin combinations are bactericidal (concentration-independent) against streptococci and staphylococci and are bacteriostatic against enterococci. While streptogramins are expected to be used in treating serious nosocomial infections caused by antibiotic-resistant, gram-positive bacteria, these agents also have a potential role for the treatment of severe cases of acute exacerbations of chronic bronchitis in the hospital setting. In […]

Peptidyl Deformylase Inhibitors

Overview The dramatic rise in S. pneumoniae resistance to penicillin, macrolides, and other antimicrobials is concerning. While the fluoroquinolones currently enjoy a low level of bacterial resistance in the community, experts expect resistance against this class to increase as they are more widely used, thereby limiting future antibacterial options. Consequently, there is considerable interest in the development of novel antimicrobials, such as peptide deformylase inhibitors, that have the potential to be active against pathogens resistant to currently available antimicrobials. Peptide deformylase is an enzyme involved in bacterial protein synthesis, and this target is highly conserved across bacterial species. Therefore, peptide deformylase inhibitors can potentially provide broad-spectrum activity. In addition, there appears […]

Dihydrofolate Reductase Inhibitors

Overview The dihydrofolate reductase (DHFR) inhibitors target bacterial DHFR, an enzyme involved in the folic acid pathway, thereby disrupting bacterial replication. DHFR inhibitors target both gram-positive and gram negative-bacteria and hence could serve as broad-spectrum antibacterials. Trimethoprim/sulfamethoxazole (Roche's Bactrim, Monarch's Septra, generics), the most common folic acid biosynthesis inhibitor, was used in the past to treat RTIs such as mild pneumonia and sinusitis. However, the emergence of S. pneumoniae resistant to trimethoprim/sulfamethoxazole, concerns regarding sulfa hypersensitivity, and poor activity against atypical RTI organisms has limited its use. Newer drugs in this class are being designed that overcome current mechanisms of resistance and provide a better spectrum of coverage against RTI pathogens. […]


Overview Glycopeptides are used for the treatment of severe or life-threatening infections that are caused by gram-positive organisms such as streptococci and staphylococci. In acute exacerbations of chronic bronchitis , they are used rarely. Physicians typically reserve them for severe acute exacerbations of chronic bronchitis episodes in which multidrug-resistant organisms are suspected or in which the patient has complications, such as bacteremia or meningitis. They are also used as second-line agents in patients who cannot receive or who have failed to respond to penicillins and cephalosporins. Glycopeptide therapy is relatively well tolerated. The most severe adverse reactions are toxicities associated with the inner ear and kidneys, but they occur only infrequently. […]


Overview Tetracyclines are the prototypical broad-spectrum antibiotic and are occasionally used as first-line agents in some markets (e.g., Germany) for the treatment of mild acute exacerbations of chronic bronchitis, particularly when cost, penicillin hypersensitivity, and β-lactam resistance are of concern. The widespread use of tetracyclines has resulted in a steady increase in the prevalence of resistance to these agents. Therefore, empiric use of tetracyclines is usually restricted to regions where resistance levels remain low or when other appropriate antibiotics are contraindicated. Although some tetracyclines have very low activity against S. pneumoniae, doxycycline maintains good antipneumococcal activity and is the tetracycline most commonly used for the treatment of acute exacerbations of chronic […]