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:
- 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
- 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
- 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.
TABLE
Available treatment and prophylactic regimens for influenza
| Drug name | Regimen for treatment* | Regimen for prophylaxis† | Comments | Cost‡ |
|---|---|---|---|---|
| Oseltamivir (Tamiflu) | 75 mg orally twice daily for 5 days | 75 mg orally once daily for >7 days | Influenza A and B | 10 tabs $59.99 (no generic) |
| Rimantidine (Flumadine) | 100 mg orally twice daily (100 mg orally once daily in elderly) | 100 mg orally twice daily (100 mg orally once daily in elderly) | Influenza A only | 14 tabs $33.45 (no generic) |
| Amantadine (Symmetrel) | 100 mg orally twice daily (100 mg orally once daily in elderly) | 100 mg orally twice daily (100 mg orally once daily in elderly) | Influenza A only (consider lower doses in debilitated patients) | 60 tabs $75.58 (brand), $18.99 (generic) |
| Zanamivir (Relenza) | 2 inhalations (10 mg) every 12 hours for 5 days | Not indicated | Influenza A and B (inhalations may be difficult to administer to debilitated patients) | 20 inhalation doses $54.41 (no generic) |
| Source: Epocrates RX: Online and PDA-Based Reference, June 12, 2004. | ||||
| * Start treatment within 48 hours of onset of symptoms. | ||||
| † Start prophylaxis immediately or within 48 hours of exposure. | ||||
| ‡ Approximate retail price from www.drugstore.com, June 2004. | ||||