Are antibiotics effective in preventing pneumonia for nursing home patients?

Journal of Family Practice, Dec, 2004 by David R. Mouw, John P. Langlois, Linda F. Turner, Jon O. Neher

* EVIDENCE-BASED ANSWER

Antibiotics should not be used for prophylaxis of pneumonia in nursing homes. We found no studies testing the effectiveness of antibiotics in preventing pneumonia in any population, including persons with predisposing conditions such as influenza. Three measures effectively prevent pneumonia in nursing home patients: influenza vaccination of residents (strength of recommendation [SOR]: B, based on systematic review of homogenous cohort observational studies); influenza vaccination of caregivers (SOR: B, based on individual randomized controlled trial); pneumococcal vaccination of residents (SOR: B, based on randomized, nonblinded clinical trials and consistent case-control studies).

Two other suggested interventions have not been extensively tested: antiviral chemoprophylaxis during an influenza outbreak in the nursing home, and oral hygiene programs for nursing home residents.

* EVIDENCE SUMMARY

Overuse of antibiotics is already a problem in nursing homes. A large portion of bacterial pneumonia in the nursing home population results from aspiration of oropharyngeal bacteria, which is more likely to be drug-resistant if the resident has been on antibiotics. (1) We found no studies that testing antibacterial agents for prevention of pneumonia in nursing home patients. However, 3 measures are clearly helpful in preventing pneumonia in nursing home patients:

1) Influenza vaccination of residents: A meta-analysis of 20 cohort studies showed a 53% efficacy (95% confidence interval [CI], 35-66)--defined as 1 minus the odds ratio--for influenza immunization in preventing pneumonia. (2)

2) Influenza vaccination of caregivers: A cluster randomized trial in British long-term care facilities demonstrated that influenza vaccination of health care workers (61% of 1078 workers) reduced the total nursing home mortality rate (odds ratio [OR]=0.56 [95% CI, 0.4-0.8]) for a drop in mortality rate from 17% to 10% (number needed to treat [NNT] =14.3). (3)

3) Pneumococcal vaccination of residents: This evidence was reviewed in a prior Clinical Inquiry. (4) The evidence comes primarily from 2 clinical trials in which the NNT to prevent 1 episode of pneumonia was about 35.

Two other proposed interventions require further study to evaluate their role in prophylaxis. Antiviral prophylaxis to prevent pneumonia during nursing home outbreaks of influenza has not been evaluated in controlled trials. Observational studies strongly suggest that amantadine, rimantadine, and oseltamivir are all effective in reducing spread of influenza during outbreaks in nursing homes (Table). Oseltamivir acts against influenza B as well as A and has fewer side effects, but it is more expensive. (5,6) Presumably, decreasing the rate of influenza also reduces the rate of subsequent pneumonia.

Oral hygiene programs for nursing home residents may also reduce pneumonia. In a single study, 366 patients in 11 Japanese nursing homes were divided into controls (self-care) and those treated with rigorous oral care (by staff). The intervention group had a relative risk of 0.6 (95% CI, 0.36-0.99; NNT=12.5) for pneumonia over a 2-year period. (7) The NNT for preventing a death by pneumonia was 11 (P<.01). This intriguing result merits follow up in larger groups in US nursing homes to see if this approach is feasible.

* RECOMMENDATIONS FROM OTHERS

There are no recommendations about the use of antibiotic prophylaxis for pneumonia in either the nursing home or in the outpatient settings; however, there are clear recommendations against the overuse of antibiotics. (8)

The CDC Advisory Committee on Immunization Practices (ACIP) recommends:

* annual influenza vaccine for persons residing in nursing homes (9)

* annual influenza vaccine for health care workers in long-term care facilities (9)

* pneumococcal vaccine for persons residing in a nursing home (the schedule for an immunocompetent adult is a single dose, followed by a booster after age 65 if the first dose was before age 65, or after 5 years for persons <65 years with compromised immune status) (10)

* chemoprophylaxis for influenza outbreaks in nursing homes. (11)

* CLINICAL COMMENTARY

Prevention is key for reducing pneumonia mortality

Pneumonia is one of the most common causes of death for nursing home patients. While pneumonia can present with the classic fever, productive cough, and air hunger, it often presents with such nonspecific findings as altered mental status or mild tachypnea, which can significantly delay diagnosis. Additionally, many older adults poorly tolerate the metabolic demands of the disease and become critically ill very rapidly. Thus, prevention remains a key strategy for reducing mortality. Nursing home policies that facilitate vaccination and reduce disease transmission are critically important in this regard.

Jon O. Neher, MD, Valley Medical Center Renton, Wash

TABLE

Available treatment
and prophylactic regimens for influenza
                                  Regimen for
               Regimen            prophylaxis *
Drug name      for treatment *    ([dagger])        Comments

Oseltamivir    75 mg orally       75 mg orally      Influenza A and B
(Tamiflu)      twice daily        once daily
               for 5 days         for >7 days
Rimantidine    100 mg orally      100 mg orally     Influenza A only
(Flumadine)    twice daily        twice daily
               (100 mg orally     (100 mg orally
               once daily in      once daily in
               elderly)           elderly)
Amantadine     100 mg orally      100 mg orally     Influenza A only
(Symmetrel)    twice daily        twice daily       (consider lower
               (100 mg orally     (100 mg orally    doses
               once daily in      once daily        in debilitated
               elderly)           in elderly)       patients)
Zanamivir      2 inhalations      Not indicated     Influenza A and B
(Relenza)      (10 mg) every                        (inhalations may be
               12 hours for                         difficult to
               5 days                               administer to de-
                                                    bilitated patients)

Drug name      Cost ([double dagger])

Oseltamivir    10 tabs $59.99
(Tamiflu)      (no generic)
Rimantidine    14 tabs $33.45
(Flumadine)    (no generic)
Amantadine     60 tabs
(Symmetrel)    $75.58 (brand),
               $18.99
               (generic)
Zanamivir      20 inhalation
(Relenza)      doses $54.41
               (no generic)

* Start treatment within 48 hours of onset of symptoms.

([dagger]) Start prophylaxis immediately or within 48 hours of
exposure.

([double dagger]) Approximate retail price from www.drugstore.com, June
2004.

Source: Epocrates RX: Online and PDA-Based Reference, June 12, 2004.