Treatment recommendations for respiratory tract infections associated with aging

Asthma and treatment with inhaled corticosteroids: associations with hospitalisations with pneumonia

BACKGROUND

Pneumonia is an important cause of morbidity and mortality. COPD patients using inhaled corticosteroids (ICS) have an increased risk of pneumonia, but less is known about whether ICS treatment in asthma also increases the risk of pneumonia. The aim of this analysis was to examine risk factors for hospitalisations with pneumonia in a general population sample with special emphasis on asthma and the use of ICS in asthmatics.

METHODS

In 1999 to 2000, 7340 subjects aged 28 to 54 years from three Swedish centres completed a brief health questionnaire. This was linked to information on hospitalisations with pneumonia from 2000 to 2010 and treatment with ICS from 2005 to 2010 held within the Swedish National Patient Register and the Swedish Prescribed Drug Register.

RESULTS

Participants with asthma (n = 587) were more likely to be hospitalised with pneumonia than participants without asthma (Hazard Ratio (HR 3.35 (1.97-5.02)). Other risk factors for pneumonia were smoking (HR 1.93 (1.22-3.06)), BMI < 20 kg/m2 (HR 2.74 (1.41-5.36)) or BMI > 30 kg/m2 (HR 2.54 (1.39-4.67)). Asthmatics (n = 586) taking continuous treatment with fluticasone propionate were at an increased risk of being hospitalized with pneumonia (incidence risk ratio (IRR) 7.92 (2.32-27.0) compared to asthmatics that had not used fluticasone propionate, whereas no significant association was found with the use of budesonide (IRR 1.23 (0.36-4.20)).

CONCLUSION

Having asthma is associated with a three times higher risk of being hospitalised for pneumonia. This analysis also indicates that there are intraclass differences between ICS compounds with respect to pneumonia risk, with an increased risk of pneumonia related to fluticasone propionate.

Novel preventive and therapuetic strategy for post-stroke pneumonia

Pneumonia is a significant complication of ischemic stroke that increases mortality. Post-stroke pneumonia is defined as newly developed pneumonia following stroke onset. Clinically and chronologically, post-stroke pneumonia is divided into two types of aspiration pneumonia. First, acute-onset post-stroke pneumonia occurs within 1 month after stroke. Second, insidious or chronic-onset post-stroke pneumonia occurs 1 month after the stroke. The mechanisms of pneumonia are apparent aspiration and dysphagia-associated microaspiration. Stroke and the post-stroke state are the most significant risk factors for aspiration pneumonia. The preventive and therapeutic strategies have been developed thoroughly and appropriate antibiotic use, and both pharmacological and nonpharmacological approaches for the treatment of post-stroke pneumonia have been studied rigorously. Increases in substance P levels, oral care, and swallowing rehabilitation are necessary to improve swallowing function in post-stroke patients, resulting in a reduction in the incidence of post-stroke pneumonia in a chronic stage. The stroke must be a cause of aspiration pneumonia.

Methicillin-resistant Staphylococcus aureus colonization is associated with higher mortality in nursing home residents with impaired cognitive status

OBJECTIVES

To assess the effect of methicillin-resistant Staphylococcus aureus (MRSA) colonization on morbidity and mortality of nursing home residents.

DESIGN

Three-year cohort study from 2000 to 2003.

SETTING

Twenty-three nursing homes of all types and regions in the northern part of Belgium (Flanders).

PARTICIPANTS

Two thousand eight hundred fourteen nursing home residents.

MEASUREMENTS

The consequences of MRSA colonization on mortality and hospitalization were studied, adjusting for potential confounders. Dates and cause of death and hospitalization were collected every 6 months during 3 years of follow-up.

RESULTS

After adjustment for age, sex, and Charlson comorbidity index, the risk for 36-month mortality remained significantly higher in MRSA carriers (hazard ratio (HR) = 1.4, 95% confidence interval (CI) = 1.1-1.8) than in noncarriers. The effect of MRSA on mortality was dependent on the degree of cognitive impairment, with the highest effect in patients with severe cognitive impairment (adjusted HR = 1.8, 95% CI = 1.1-2.8) and absence of effect in residents with good mental status (adjusted HR = 0.8, 95% CI = 0.43-1.62). Deaths were more frequently reported to be infection-related in MRSA carriers. No association was found between MRSA colonization and hospitalization for any reason, but during follow-up, MRSA carriers were twice as frequently hospitalized for respiratory tract infections.

CONCLUSION

Colonization of MRSA in Belgian nursing home residents was associated with higher mortality. This excess mortality was restricted to residents with impaired cognitive function, probably reflecting differences in therapeutic approaches, in delay of diagnosis of pneumonia and other acute disorders in these patients, or in both.

What's the basis for treating infections your way? Quality assessment of review articles on the treatment of urinary and respiratory tract infections in older people

OBJECTIVE

To assess the quality of readily available review articles on urinary and respiratory tract infections in older people.

METHODS

Data sources were articles identified by MEDLINE search (1988-1998), review of the bibliographies of identified publications, textbooks from the library of a geriatric university hospital, and booklets with general guidelines on antibiotic therapy. Selection was made of review articles or book chapters about urinary and/or respiratory tract infections in older people that were readily available, ie, in Swiss medical libraries. Quality was assessed according to clinical applicability of the recommendations, methodology of the review, type of literature cited in the bibliography, and age of the population included in these reference articles.

RESULTS

Only 13 of 29 (45%) review articles about urinary tract infections and seven of 29 (24%) articles about respiratory tract infections satisfied our criteria of applicability. Specifically, dosage, route of administration, and treatment duration were often not described. The overall methodological quality was low (mean score 1.9 +/- 1.0 on a scale of 9). No review specified the methods used to identify, select, and validate included information. Authors of the review articles quoted an important number of other review articles and only a small number of clinical trials. Less than one-quarter of these clinical trials actually comprised primarily an older population.

CONCLUSIONS

Review articles on treatment of common infectious diseases in older people are often neither clinically applicable nor of good methodological quality. Therefore, more systematic review articles regarding treatment of older patients, as well as evidence-based practice guidelines, are needed.

Pneumonia: the impact of antibiotic resistance on its management

Pneumonia in the community affects between 1 and 5 per 1000 per year. The microbial aetiology is diverse and influenced by preexisting disease, seasonality, as well as animate and inanimate environmental sources; pneumococci, Legionella spp., Mycoplasma pneumoniae, and more recently Chlamydia pneumoniae are the predominant bacterial pathogens. Gram-negative enteric bacteria although less common are particularly virulent. Antibiotic resistance is well established for Haemophilus influenzae and Gram-negative bacillary infections, but has been a recent phenomenon in the case of Streptococcus pneumoniae, which is numerically the leading pathogen. Despite the concerns raised by this reduced susceptibility to penicillin, evidence that this has been translated into increased clinical failures is currently difficult to establish. Macrolide and tetracycline resistance among pneumococci is more common. beta-Lactamase production by H. influenzae has now reached levels where, in those with severe pneumonia, beta-lactamase stable agents are preferred. Consensus Guidelines on the treatment of community acquired pneumonia have been published by the British Thoracic Society, the American Thoracic Society, and from Expert Panels in Canada and France. These emphasize severity assessment and differentiate management in the community or hospital setting. The recommended regimens are compared and contrasted. In conclusion, mild/moderate pneumonia, when pneumococcal in nature, is likely to still respond to amoxycillin or penicillin G, but in higher dosages where pneumococcal resistance is documented. However, in severe infection where pneumococcal resistance, other beta-lactamase-producing pathogens, or an atypical infection could be operating, it is important that initial empirical therapy be broad spectrum and promptly administered. Treating multiresistant pneumococcal disease in those allergic to beta-lactams presents a particular dilemma. Glycopeptides are currently preferred.

Nursing home-acquired pneumonia

Nursing Home-Acquired Pneumonia is a significant infection that is often seen in the long-term care setting. It is associated with substantial morbidity, healthcare expenditure, and mortality rates as high as 44%. Uniform diagnosis and therapeutic strategies have not been specifically established for pneumonia in the nursing home setting. This paper will update the long-term care provider with the unique features and challenges of pneumonia in this setting and review the approaches to the diagnosis and treatment of this important illness. The discussion will conclude with details regarding overall prevention of nursing home-acquired pneumonia and the critical role played by the nursing home medical director in this process.

Smoking and urological disease

It is important to realise that virtually every part of the body, including the urological system, is adversely affected by smoking. Smoking is the most important known preventable cause of urinary bladder cancer and is also associated with a risk of prostatic and renal cancer. The exact mechanism by which smoking increases the incidence of urological malignancy is not known. One possibility is that chemicals in cigarette smoke inhibit the synthesis of cytoprotective eicosanoids. Deficient local protection, against the hostile environment caused by the presence of urine, could then encourage the process of carcinogenesis. Smoking is a powerful predictor of erectile dysfunction; cessation may restore normal function. Cigarette smoke also exerts adverse effects on sperm motility and count. Although there is no convincing evidence of reduced fertility in male smokers, it is advisable for men to quit smoking should they have marginal semen quality and wish to start a family. Smoking causes substantial urological pathology; these facts can be used to convince patients with urological problems to quit smoking.

Clarithromycin. A review of its efficacy in the treatment of respiratory tract infections in immunocompetent patients

Clarithromycin is a broad spectrum macrolide antibacterial agent active in vitro and effective in vivo against the major pathogens responsible for respiratory tract infections in immunocompetent patients. It is highly active in vitro against pathogens causing atypical pneumonia (Chlamydia pneumoniae, Mycoplasma pneumoniae and Legionella spp.) and has similar activity to other macrolides against Staphylococcus aureus. Streptococcus pyogenes, Moraxella catarrhalis and Streptococcus pneumoniae. Haemophilus influenzae is susceptible or intermediately susceptible to clarithromycin alone, but activity is enhanced when the parent drug and metabolite are combined in vitro. Absorption of clarithromycin is unaffected by food. More than half of an oral dose is systemically available as the parent drug and the active 14-hydroxy metabolite. Pharmacokinetics are nonlinear, with plasma concentrations increasing in more than proportion to the dosage. First-pass metabolism results in the rapid appearance of the active metabolite 14-hydroxy-clarithromycin in plasma. Clarithromycin and its active metabolite are found in greater concentrations in the tissues and fluids of the respiratory tract than in plasma. Dosage adjustments are required for patients with severe renal failure, but not for elderly patients or those with hepatic impairment. Drug interactions related to the cytochrome P450 system may occur with clarithromycin use. In addition to the standard immediate-release formulation for administration twice daily, a modified-release formulation of clarithromycin is now available for use once daily. In dosages of 500 to 1000 mg/day for 5 to 14 days, clarithromycin was as effective in the treatment of community-acquired upper and lower respiratory tract infections in hospital and community settings as beta-lactam agents (with or without a beta-lactamase inhibitor), cephalosporins and most other macrolides. Clarithromycin was similar in efficacy to azithromycin in comparative studies and is as effective as and better tolerated than erythromycin. Adverse events are primarily gastrointestinal in nature, but result in fewer withdrawals from therapy than are seen with erythromycin. Clarithromycin provides similar clinical and bacteriological efficacy to that seen with beta-lactam agents, cephalosporins and other macrolides. It offers a cost-saving alternative to intravenous erythromycin use in US hospitals and is available in both once-daily and twice-daily formulations. The spectrum of activity of clarithromycin against common and emerging respiratory tract pathogens may make it suitable for use in the community as empirical therapy of respiratory tract infections in both children and adults.

Azithromycin. A review of its pharmacological properties and use as 3-day therapy in respiratory tract infections

The azalide antibacterial agent azithromycin is a semisynthetic acid-stable erythromycin derivative with an expanded spectrum of activity and improved tissue pharmacokinetic characteristics relative to erythromycin. The drug is noted for its activity against some Gram-negative organisms associated with respiratory tract infections, particularly Haemophilus influenzae. Azithromycin has similar activity to other macrolides against Streptococcus pneumoniae and Moraxella catarrhalis, and is active against atypical pathogens such as Legionella pneumophila, Chlamydia pneumoniae and Mycoplasma pneumoniae. Once-daily administration of azithromycin is made possible by the long elimination half-life of the drug from tissue. Azithromycin is rapidly and highly concentrated in a number of cell types after absorption, including leucocytes, monocytes and macrophages. It undergoes extensive distribution into tissue, from where it is subsequently eliminated slowly. A 3-day oral regimen of once-daily azithromycin has been shown to be as effective as 5- to 10-day courses of other more frequently administered antibacterial agents [such as erythromycin, amoxicillin-clavulanic acid and phenoxymethylpenicillin (penicillin V)] in patients with acute exacerbations of chronic bronchitis, pneumonia, sinusitis, pharyngitis, tonsillitis and otitis media. Adverse effects of azithromycin are mainly gastrointestinal in nature and occur less frequently than with erythromycin. Azithromycin is likely to prove most useful as a 3-day regimen in the empirical management of respiratory tract infections in the community. Its ease of administration and 3-day duration of therapy, together with its good gastrointestinal tolerability, should optimise patient compliance (the highest level of which is achieved with once-daily regimens). Azithromycin is also likely to be useful in the hospital setting, particularly for outpatients and for those unable to tolerate erythromycin.

The antibiotic treatment of community-acquired, atypical, and nosocomial pneumonias

Optimal antibiotic regimens and duration of treatment are not universally agreed on for community-acquired or nosocomial pneumonias. Experience suggests that community-acquired pneumonias may be treated for less than 2 weeks with a combination of intravenous and oral antibiotics of appropriate spectrum that penetrate the lung, have a good safety profile, do not foster the development of resistance, and are cost-effective. After initial intravenous therapy, oral switch therapy may be begun as soon as the patient defervesces clinically, which is usually 3 days after admission. Switching to oral therapy does not invariably lead to earlier hospital discharge. There is no "standard of care" for pneumonias, but guidelines for empiric use have existed for decades. The least expensive beta-lactamase stable antibiotic should be used as monotherapy for the empiric treatment of community-acquired pneumonia. Because community-acquired atypical pneumonias are clinically distinct from bacterial pneumonias owing to their extrapulmonary features, clinicians should be able to differentiate atypical pneumonias from bacterial pneumonias, which permits prompt and appropriate treatment. Nosocomial pneumonias remain a difficult diagnostic challenge. Therapeutically the most important principle in treating nosocomial pneumonia is to provide for double-drug coverage against P. aeruginosa. Differentiation of respiratory tract colonization from respiratory tract invasion remains the central key issue in patients with pulmonary infiltrates acquired during hospitalization. Most patients complete their course of intravenous therapy for nosocomial pneumonia leaving little or no time for completion of their therapy by oral antibiotics. Hospital-acquired atypical pneumonias are largely limited to legionnaires' disease, which is a more difficult diagnosis than in the community-acquired setting. Clinicians taking care of patients with pneumonia should employ a simplified therapeutic approach using a single drug for community-acquired infections. The use of additional antibiotics to increase gram-negative coverage is medically unjustified and not cost-effective and is to be discouraged. The most cost-effective strategy for the treatment of community-acquired pneumonias is to switch the patient from an intravenous to an oral antibiotic as soon as the patient clinically defervesces and is able to take oral medications. Antimediator therapies have no role in the treatment of community-acquired or nosocomial pneumonias.

Physiological changes due to age. Implications for respiratory drug therapy

The pulmonary system is modified in various ways over time and it is particularly vulnerable to environmental insults. Of particular interest are the implications of aging for therapy of respiratory illnesses. The changes in pulmonary structure and function due simply to aging, and changes due to diseases, should be distinguished from each other. The great reserve function of the lung permits reasonable physical capacity in healthy individuals despite aging changes. In principle, loss of function equivalent to more than one lung is necessary to impair aerobic capacity at any age. Elderly people are subject to the same respiratory diseases as younger adults but may manifest them differently. They may present in atypical ways such as in bacterial pneumonia, tuberculosis, and asthma, all modified by anatomical alterations or deterioration of immunological defence mechanisms. Accumulation of toxic substances over time such as cigarette smoke or environmental pollutants may give rise to chronic bronchitis, emphysema, bronchogenic carcinoma and interstitial lung disease. Changes in the number or function of airway receptors modulate responses to bronchodilator drugs. Chronic inflammation of the bronchial wall has blurred the distinction between traditional asthma and chronic bronchitis and emphysema, and similar drug therapy can be useful for all. Adverse reactions to respiratory drugs such as theophylline, oral corticosteroids, and isoniazid increase with age. As more data accumulate, drug therapy of respiratory diseases in older patients will become more effective and safer.