Penicillin

About: Penicillin is a research topic. Over the lifetime, 17916 publications have been published within this topic receiving 368480 citations. The topic is also known as: penicillin antibiotic & PCN.

Observations on the Mechanism of Action of Penicillin.

Abstract: SummaryPenicillin acts either as a bacteriostatic or bactericidal agent depending on the experimental conditions. The number of organisms decreases at a constant rate until 99% of the organisms hav...

Risk factors and response to antibiotic therapy in adults with bacteremic pneumonia caused by penicillin-resistant pneumococci.

Abstract: We retrospectively studied 24 adults with bacteremic pneumonia (25 episodes) due to penicillin-resistant pneumococci, for which the minimal inhibitory concentrations (MICs) of penicillin G were 0.12 to 8.0 μg per milliliter; 79 percent of the strains showed multiple antibiotic resistance. As compared with 48 control patients with bacteremic pneumonia caused by penicillin-sensitive pneumococci, the 24 patients with penicillin-resistant pneumococci had a significantly higher incidence of use of β-lactam antibiotics during the previous three months (65 vs. 17 percent, P = 0.0008), hospitalizaron during the previous three months (58 vs. 21 percent, P = 0.0038), nosocomial pneumonia (37 vs. 6 percent, P = 0.0032), episodes of pneumonia during the previous year (29 vs. 4 percent, P = 0.010), and factors on initial presentation that were associated with a poor prognosis (an initially critical condition) (67 vs. 27 percent, P = 0.0030). Their overall mortality rate was significantly higher (54 vs. 25 per...

Treatment of Acute Streptococcal Pharyngitis and Prevention of Rheumatic Fever: A Statement for Health Professionals

Abstract: Primary prevention of acute rheumatic fever is accomplished by proper identification and adequate antibiotic treatment of group A beta-hemolytic streptococcal (GAS) tonsillopharyngitis. Diagnosis of GAS pharyngitis is best accomplished by a throat culture. Penicillin (either oral penicillin V or injectable benzathine penicillin) remains the treatment of choice, because it is cost effective, has a narrow spectrum of activity, has long-standing proven efficacy, and GAS resistant to penicillin have not been documented. Various macrolides, oral cephalosporins, and other beta-lactam agents are acceptable alternatives, particularly in penicillin-allergic individuals. The individual who has had an attack of rheumatic fever is at very high risk of developing recurrences after subsequent GAS pharyngitis and needs continuous antimicrobial prophylaxis to prevent such recurrences (secondary prevention). The duration of prophylaxis depends on the number of previous attacks, the time lapsed since the last attack, the risk of exposure to streptococcal infections, the age of the patient, and the presence or absence of cardiac involvement. Penicillin is again the agent of choice for secondary prophylaxis, but sulfadiazine or erythromycin are acceptable alternatives in penicillin-allergic individuals. This report is an update of a 1988 statement by this committee. It expands on the previous statement, includes more recent therapeutic modalities, and makes more specific recommendations for the duration of secondary prophylaxis.

Immediate hypersensitivity reactions to beta-lactam antibiotics.

Abstract: Allergic reactions to the beta-lactam antibiotics (penicillins, cephalosporins, carbapenems, and monobactams) are a major factor limiting their use. Immediate hypersensitivity reactions to penicillins depend on the presence of preformed allergic (IgE) antibodies to several penicillin determinants. These materials can be used in in-vivo skin testing to exclude those patients at risk for immediate or accelerated allergic reactions. The cephalosporins have not had their relevant determinants defined as related to allergic reactions. The results of in-vivo challenges of patients with IgE to penicillin suggest the incidence of reactivity of cephalosporins in patients allergic to penicillin is less than generally appreciated. The monocyclic beta-lactam antibiotic, aztreonam (a monobactam), failed to show cross-reactivity with penicillin antibodies, because immune reactivity toward the monobactam was directed against side chain rather than nuclear determinants. On the other hand, the new bicyclic carbapenem beta-lactam drugs, represented by imipenem, showed extensive in-vivo cross-reactivity with penicillins.