Drugs are now being developed that need to be taken only once a day or for only three days. Antibiotics need to be administered intravenously or by injection for severe pneumonia. Intravenous antibiotics are first given in the hospital, usually from five to ten days, depending on severity. If the patient is stabilized but still requires longer-term intravenous antibiotics, the procedure can often be performed at home. Individualized medical decisions are required to select the best antibiotic.
All antibiotics carry the risk for allergic reactions, which can be serious in some cases.
The most common side effect for nearly all antibiotics is gastrointestinal distress. They double the risk for vaginal infections in women. Of major concern for physicians and the public is the emergence of strains of common bacteria that are resistant to specific antibiotics and even those that are now resistant to a wide spectrum of antibiotics. The prevalence of such bacteria has dramatically increased worldwide, and, although resistance is highest to penicillin, it is also increasing rapidly to other antibiotics. Fortunately, most pneumococci are still sensitive to vancomycin and to the newer fluoroquinolones such as levofloxacin and trovafloxacin.