Penicillin streptococcal

Acute pharyngitis presents a diagnostic and therapeutic dilemma. The majority of sore throats are caused by a variety of viruses fewer than 20% are bacterial and hence potentially responsive to antibiotic therapy. However, antibiotics are widely prescribed and this reflects the difficulty in discriminating streptococcal from non-streptococcal infections clinically in the absence of microbiological documentation. Nonetheless, Strep, pyogenes is the most important bacterial pathogen and this responds to oral penicillin. However, up to 10 days treatment is required for its eradication fixm the throat. This requirement causes problems with compliance since symptomatic improvement generally occurs within 2-3 days. 

Staphylococcus aureus is responsible for a variety of skin infections which require therapeutic approaches different from those of streptococcal infections. Staphylococcal celluhtis is indistinguishable clinically from streptococcal cellulitis and responds to cloxacillin or flucloxacillin, but generally fails to respond to penicillin owing to penicillinase (/3-lactamase) production. Staphylococcus aureus is an important cause of superficial, localized skin sepsis which varies ftom small pustules to boils and occasionally to a more deeply invasive, suppurative skin abscess known as a carbuncle. Antibiotics are generally not indicated for these conditions. Pustules and boils settle with antiseptic soaps or creams and often discharge spontaneously, whereas carbuncles frequently require surgical drainage. Staphylococcus aureus may also cause... 

Penicillin is the dmg of choice for the treatment of group B streptococcal, meningococcal and pneumococcal infections but, as discussed earlier, CSF concentrations of penicillin are significantly influenced by the intensity of the inflammatoiy response. To achieve therapeutic concentrations within the CSF, high dosages are required, and in the case of pneumococcal meningitis should be continued for 10-14 days. 

The antibiotic of choice for group B streptococcal disease is penicillin G, although ampicillin is an alternative.43 No resistance to either agent has been reported, and their narrow spectrum of activity makes them ideal choices.43 Resistance has developed with the use of alternative choices for penicillin-allergic patients. A treatment algorithm for group B Streptococcus is shown in Fig. 44—3, and dosing recommendations are shown in Table 44-5. 

Penicillin is the drug of choice for streptococcal pharyngitis, but cephalosporins may be appropriate alternative first-line agents owing to increasing failure rates after penicillin therapy. 

Casey JR, Pichichero ME. Meta-analysis of cephalosporin versus penicillin treatment of group A streptococcal tonsillopharyngi-tis in children. Pediatrics 2004 113(4) 866-882. 

Licosamides Clindamycin and lincomycin Serious staph-, pneumo-, and streptococcal infections in penicillin-allergic patients, also anaerobic infections... 

P -Lactam and penicillins Amoxicillin, novamax Wide range of streptococcal infections, syphilis and Lyme diseases... 

As streptococcal cellulitis is indistinguishable clinically from staphylococcal cellulitis, administration of a semisynthetic penicillin (nafrillin or oxacillin) or first-generation cephalosporin (cefazolin) is recommended until a definitive diagnosis, by skin or blood cultures, can be made (Table 47-4). If documented to be a mild cellulitis secondary to streptococci, oral penicillin VK, or intramuscular procaine penicillin may be administered. More severe streptococcal infections should be treated with IV antibiotics (such as ceftriaxone 50 to 100 mg/kg as a single dose). 

Streptococcal infections 1.2 MU IM. Many streptococcal strains are now resistant to penicillin. 

Streptococcal In penicillin-sensitive alpha and nonhemolytic streptococci, use streptomycin for 2 weeks with penicillin 1 g twice daily for 1 week, 0.5 g twice daily for the second week. If patient is older than 60 years of age, give 0.5 g twice daily for the entire 2-week period. 

In most cases one week of i.v. penicillin is adequate for meningococal meningitis. Ten to 14 days is recommended for pneumococcal meningitis. Two to 3 weeks for Listeria and group B streptococcal meningitis and 3 weeks is necessary for gramnegative meningitis. 

Streptococci are generally highly sensitive to penicillin G (MIC <0.1 mg/1), albeit that some strains are more resistant (MIC O.I-I.O mg/1). Thus, streptococcal endocarditis can be treated with a... 

Obstetric infections can be treated with penicillin-beta-lactamase inhibitors such as amoxicillin-clavulanic acid, with extended spectrum penicillins (with or without beta-lacamase inhibitors if justified by local resistance surveillance data), with a first or second generation cephalosporin combined with metronidazole. In severe cases of streptococcal infection high doses of penicillin in combination with clindamycin is the treatment of choice. In amnionitis, maternal morbidity resolves with delivery. In endometritis, antibiotics should be stopped after the... 

Oral beta-lactam antibiotics such as amoxycillin, cotrimoxazole or doxycycline for 7-10 days are suitable for the treatment of bacterial sinusitis. Furuncles of the nose should be treated with an anti-staphyloccal drug for 5 days. Standard treatment for streptococcal pharyngitis consists of 10 days of penicillin. Malignant otitis externa responds to high dose quinolone therapy (e.g. ciprofloxacin 750 mg 2 t.d.) administered orally. For parapharyngeal abscess, high dose penicillin plus beta-lactamase inhibitors such as amoxycillin-clavulanic acid can be used. Duration of treatment is guided by clinical and parameters of inflammation, and abscesses often need several weeks to resolve by conservative treatment. 

Sulfadiazine and sulfisoxazole still play a useful role in the prophylaxis of group A streptococcal infections in patients with rheumatic fever who are hypersensitive to penicillin. This is tempered with the potential for toxicity and infection with resistant Streptococcus pyogenes. 

When prescribing one of the penicillin G depot formulations, practitioners must individualize treatment to clinical and microbial conditions. Some long-acting formulations may not maintain adequate plasma and tissue concentrations to treat specific organisms or infections. For acute streptococcal meningitis, the goal is rapid... 

Penicillin V is an orally administered phenoxy-methyl congener of penicillin G having an antibacterial spectrum of activity that is similar to that of penicillin G. Penicillin V is used to treat streptococcal infections when oral therapy is appropriate and desirable. 

Erythromycin is effective in the treatment and prevention of S. pyogenes and other streptococcal infections, but not those caused by the more resistant fecal streptococci. Staphylococci are generally susceptible to erythromycin, so this antibiotic is a suitable alternative drug for the penicillin-hypersensitive individual. It is a second-line drug for the treatment of gonorrhea and syphilis. Although erythromycin is popular for the treatment of middle ear and sinus infections, including H. influenzae, possible erythromycin-resistant S. pneumoniae is a concern. 

L., Leonard, H.L., Witowski, M.E., Dubbert, B., and Swedo, S.E. (1999) A pilot study of penicillin prophylaxis for neuropsychiatric symptom exacerbations triggered by streptococcal infections. Biol Psychiatry 45 1564—1571. 

Hetning serendipitously discovers antibacterial properties of penicillin Mietzach, Klarer, Domagk introduce first anti-streptococcal drug Ruzicka first synthesizes progesterone... 

Streptococcal infections Pharyngitis, rheumatic fever, otitis media and even for subacute bacterial endocarditis. Staphylococcal infections Penicillinase resistant penicillin can be used. Meningococcal infections Meningitis other infections caused by meningococci. 

Benzathine and procaine penicillins are formulated to delay absorption, resulting in prolonged blood and tissue concentrations. A single intramuscular injection of 1.2 million units of benzathine penicillin maintains serum levels above 0.02 mcg/mL for 10 days, sufficient to treat B-hemolytic streptococcal infection. After 3 weeks, levels still exceed 0.003 mcg/mL, which is enough to prevent B-hemolytic streptococcal infection. A 600,000 unit dose of procaine penicillin yields peak concentrations of 1-2 mcg/mL and clinically useful concentrations for 12-24 hours after a single intramuscular injection. 

Benzathine penicillin and procaine penicillin G for intramuscular injection yield low but prolonged drug levels. A single intramuscular injection of benzathine penicillin, 1.2 million units, is effective treatment for 3-hemolytic streptococcal pharyngitis given intramuscularly once every 3-4 weeks, it prevents reinfection. Benzathine penicillin G, 2.4 million units intramuscularly once a week for 1-3 weeks, is effective in the treatment of syphilis. Procaine penicillin G, formerly a work horse for treating uncomplicated pneumococcal pneumonia or gonorrhea, is rarely used now because many strains are penicillin-resistant. 

Cefazolin penetrates well into most tissues. It is a drug of choice for surgical prophylaxis. Cefazolin may be a choice in infections for which it is the least toxic drug (eg, penicillinase-producing E coli or pneumoniae) and in persons with staphylococcal or streptococcal infections who have a history of penicillin allergy other than immediate hypersensitivity. Cefazolin does not penetrate the central nervous system and cannot be used to treat meningitis. Cefazolin is an alternative to an antistaphylococcal penicillin for patients who are allergic to penicillin. 

Penicillin G Prevents bacterial cell wall synthesis by binding to and inhibiting cell wall transpeptidases Rapid bactericidal activity against susceptible bacteria Streptococcal infections, meningococcal infections, neurosyphilis IV administration rapid renal clearance (half-life 30 min, so requires frequent dosing (every 4 h) Toxicity Immediate hypersensitivity, rash, seizures... 

Penicillin plus streptomycin is effective for enterococcal endocarditis and 2-week therapy of viridans streptococcal endocarditis. Gentamicin has largely replaced streptomycin for these indications. Streptomycin remains a useful agent for treating enterococcal infections, however, because approximately 15% of enterococcal isolates that are resistant to gentamicin (and therefore to netilmicin, tobramycin, and amikacin) will be susceptible to streptomycin. 

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