Drug Update: Oral Drugs for Community-Acquired Pneumonia.
Because it often takes 48 hours to obtain laboratory results, CAP is usually treated empirically, with physicians relying on an educated guess about the infecting pathogen when choosing a therapy.
Treatment has become more complicated in recent years. Half of the pneumococci causing CAP may be penicillin resistant in some regions, and as many as a quarter of CAP cases may be caused by atypical pathogens such as Mycoplasma pneumoniae. Broad-spectrum quinolones have become a popular treatment option because of their wide coverage, but many worry that overuse of wide-spectrum drugs will fuel higher resistance rates.
Because so many patient and resistance factors must be considered when choosing a therapy, experts recommend following CAP treatment guidelines such as those published last year by the Infectious Diseases Society of America. All of the drugs listed, except for azithromycin and cefpodoxime, are usually used for 7-14 days, with 10 days the standard duration.
Quinolones are suspected to be a cause of arthropathy in young children and thus should never be used in pregnant or lactating women. Doxycycline causes permanent teeth staining in children and should likewise be avoided in pregnant or lactating women.
Finally, experts emphasize that only 40% of eligible whites, 25% of eligible blacks, and 20% of eligible Hispanics receive pneumococcal vaccination in any given year. Many CAP cases could be avoided by more vigilant use of preventive measures.
DRUG DOSAGE COST/TREATMENT [*] MACROLIDES azithromycin 500 mg day 1 $39.30 (5 days) (Zithromax) followed by 250 mg/day for 4 days clarithromycin 500 mg b.i.d. $65.20 (10 days) (Biaxin) 7-14 days erythromycin 500 mg q.i.d. $9.60 (10 days) QUINOLONES levofloxacin 500 mg once a $80.60 (10 days) (Levaquin) day trovafloxacin 200 mg once a $71.90 (10 days) (Trovan) day ciprofloxacin 750 mg b.i.d. $79.80 (10 days) (Cipro) grepafloxacin 600 mg once a $61.80 (10 days) (Raxar) day sparfloxacin 400 mg day 1 $73.48 (10 days) (Zagam) followed by 200 mg/day for 9 days PENICILLIN amoxicillin 500 mg t.i.d. $10.80 (10 days) TETRACYCLINE doxycycline 100 mg b.i.d. $9.00 (10 days) CEPHALOSPORIN cefpodoxime 200 mg b.i.d. $109.48 (14 days) (Vantin) TRIMETHOPRIM-SULFAMETHOXAZOLE trimethoprim- 160 mg/800 mg $12.60 (10 days) sulfamethoxazole t.i.d. DRUG COMMENT MACROLIDES azithromycin The most active macrolide monotherapy against Haemophilus influenzae. Long half-life and (Zithromax) concentration in immune cells of the lung allow once-a-day dosing. Five-day course may be more convenient than the 10- to 14-day course that's usually needed for all other drugs. Consider adding a [beta]-lactam to a macrolide in older patients with comorbid illness to cover gram-negative organisms, which may coexist with other pathogens. clarithromycin Unlike azithromycin, requires b.i.d. dosing and longer treatment. Not approved for pneumonia due (Biaxin) to H. influenzae. Consider adding a [beta]-lactam to a macrolide in older patients with comorbid illness to cover possible gram negatives that could coexist with other pathogens. erythromycin Least convenient macrolide to use but also the cheapest. Potential for more gastrointestinal upset may make it less attractive than other macrolides. Inconsistent activity against H. influenzae. QUINOLONES levofloxacin Antipneumococcal activity makes it and trovafloxacin the quinolones of choice for empiric (Levaquin) pneumonia therapy for many experts. Once-a-day dosing of most quinolones is an advantage. trovafloxacin In June the Food and Drug Administration issued an advisory on the risk of liver toxicity. Can still (Trovan) be used to treat serious and life-threatening cases of CAP. Stop on signs of liver dysfunction or after a maximum of 14 days. Excellent activity against pneumococci, including penicillin-resistant strains; slightly more potent than levofloxacin; and longer half-life than levofloxacin. ciprofloxacin Twice-a-day dosing and borderline activity against pneumococci have diminished use. No longer (Cipro) considered appropriate by many experts. grepafloxacin Few comparative studies with other agents. Not a drug of choice. (Raxar) sparfloxacin Causes phototoxicity and photosensitivity. No longer marketed for pneumonia. (Zagam) PENICILLIN amoxicillin Effective against sensitive pneumococci but generally not preferred for empiric treatment. Does not cover atypical pathogens, many H. influenzae strains, or penicillin-resistant pneumococci unless used in higher doses. TETRACYCLINE doxycycline Still recommended by many experts. Good activity against H. influenzae, atypical pathogens, and many pneumococci but not against penicillin-resistant species. May be effective monotherapy in younger, otherwise healthy patients. CEPHALOSPORIN cefpodoxime Good activity against S. pneumoniae and H. influenzae but not against atypical pathogens. Role in (Vantin) empiric therapy is very limited; basically an adjuvant therapy for macrolides. TRIMETHOPRIM-SULFAMETHOXAZOLE trimethoprim- No longer accepted as monotherapy for CAP due to low activity against atypical pathogens and sulfamethoxazole rising levels of pneumococcal resistance. (*.)Cost is based on average wholesale price in the 1999 Red Book for 100-unit package, or closest size, of generic formulation, unless otherwise indicated. Sources: Dr. Steven R. Mostow, professor of medicine, University of Colorado, Denver. Dr. Michael S. Niederman, professor of medicine, State University of New York at Stony Brook. Dr. Victor Yu, professor of medicine, University of Pittsburgh.
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|Author:||Zoler, Mitchel L.; Zwillich, Todd|
|Publication:||Family Practice News|
|Date:||Oct 1, 1999|
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