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penicillin /pen·i·cil·lin/ ( pen″ĭ-sil´in) any of a large group of natural (p. G, p.V) or semisynthetic antibacterial antibiotics derived directly or indirectly from strains of fungi of the genus Penicillium and other soil-inhabiting fungi, which exert a bactericidal as well as a bacteriostatic effect on susceptible bacteria by interfering with the final stages of the synthesis of peptidoglycan, a substance in the bacterial cell wall. The penicillins, despite their relatively low toxicity for the host, are active against many bacteria, especially gram-positive pathogens (streptococci, staphylococci, pneumococci); clostridia; some gram-negative forms (gonococci, meningococci); some spirochetes (Treponema pallidum and T. pertenue ); and some fungi. Certain strains of some target species, e.g., staphylococci, secrete the enzyme penicillinase, which inactivates penicillin and confers resistance to the antibiotic.
penicillin [pen′isil′in] Etymology: L, penicillus, paintbrush any one of a group of antibiotics derived from cultures of species of the fungus Panieillium or produced semisynthetically. Various penicillins administered orally or parenterally for the treatment of bacterial infections exert their antimicrobial action by inhibiting the biosynthesis of cell-wall mucopeptides during active multiplication of the organisms. Penicillin G is a widely-used therapeutic agent for meningococcal, pneumococcal and streptococcal infections; syphilis; and other diseases. It is rapidly absorbed when injected intramuscularly or subcutaneously, but it is inactivated by gastric acid and hydrolyzed by penicillinase produced by most strains of Staphylococcus aureus. Penicillin V is also active against gram-positive cocci, with the exception of penicillinase-producing staphylococci, and, because it is resistant to gastric acid, it is effective when administered orally. Penicillins resistant to the action of the enzyme penicillinase (beta-lactamase) are cloxacillin, dicloxacillin, methicillin, nafcillin, and oxacillin. Ampicillin and amoxicillin are broad-spectrum aminopenicillins active against gram-negative organisms, including Escherichia coli, Haemophilus influenzae, Neisseria gonorrhoeae, Salmonella, Shigella, and Proteus mirabilis. Extended-spectrum penicillins include carbenicillin, piperacillin, and ticarcillin. These drugs are effective against the same bacteria killed by the aminopenicillins and are also effective against a number of additional bacteria, including species of Pseudomonas, Enterobacter, Klebsiella, Proteus, and Bacteroides. Hypersensitivity reactions are common in patients receiving penicillin and may appear in the absence of prior exposure to the drug, presumably because of unrecognized exposure to a food or other substance containing traces of the antibiotic. The most common hypersensitivity reactions are rash, fever, and bronchospasm, followed in frequency by vasculitis, serum sickness, and exfoliative dermatitis. In some patients severe erythema multiforme accompanied by headache, fever, arthralgia, and conjunctivitis (Stevens-Johnson syndrome) develop. The most frequent cause of anaphylactic shock is an injection of penicillin.
penicillin (pen´isil´in),n an antibiotic secured from cultures of
P. notatum, being bactericidal for gram-positive cocci, some gram-negative cocci (gonococcus and meningococcus), and clostridial and spirochetal organisms. Its topical application to the oral mucusa membranes is discouraged because of the high risk of sensitization from local application of antibiotic substances. penicillin G, n an acid-sensitive form of penicillin prepared as penicillin G benzathine and penicillin G procaine used for deep intramuscular administration. It is slowly released, resulting in prolonged effective blood levels. In past dentistry, it was used prophylactically for patients predisposed to bacterial endocarditis prior to any invasive dental procedure. Now it has been replaced by amoxicillin. It has a high allergy potential. See also penicillin G benzathine. penicillin G benzathine, n brand names: Bicillin L-A, Permapen;
drug class: benzathine salt of natural penicillin;
action: interferes with cell wall replication of susceptible organisms; osmotically unstable cell wall swells and bursts from osmotic pressure;
uses: respiratory infections, scarlet fever, erysipelas, otitis media, pneumonia, skin and soft tissue infections, and yaws. penicillin V potassium/penicillin V, n brand names: Beepen-VK, Betapen-VK, V-Cillin K, Veetids, others;
drug class: semisynthetic penicillin;
action: interferes with cell wall replication of susceptible organisms; the cell wall, rendered osmotically unstable, swells and bursts from osmotic pressure;
uses: effective for both gram-positive cocci and gram-negative bacilli.
penicillin any of a large group of natural or semisynthetic antibacterial antibiotics derived directly or indirectly from strains of fungi of the genus Penicillium and other soil-inhabiting fungi grown on special culture media. Penicillins exert a bactericidal as well as a bacteriostatic effect on susceptible bacteria by interfering with the final stages of the synthesis of peptidoglycan, a substance in the bacterial cell wall. Despite their relatively low toxicity for the host, they are active against many bacteria, especially gram-positive pathogens (streptococci, staphylococci); clostridia; certain gram-negative forms; certain spirochetes (Treponema pallidum and T. pertenue); and certain fungi. Certain strains of some target species, for example staphylococci, secrete the enzyme penicillinase, which inactivates penicillin and confers resistance to the antibiotic. Some of the newer penicillins, for example methicillin, are more effective against penicillinase-producing organisms. An additional class of extended-spectrum penicillins has been approved for use; it includes piperacillin and mezlocillin. There are four groups of penicillins, the natural penicillins, penicillin G and penicillin V, with a narrow spectrum of activity, mainly against gram-positive bacteria; the aminopenicillins (amoxicillin, ampicillin and hetacillin) are semisynthetic derivatives and have a broad spectrum of activity against gram-positive and many gram-negative organisms, but are susceptible to penicillinase-producing Staphylococcus spp.; penicillinase-resistant penicillins, which include cloxacillin, methicillin, nafcillin and oxacillin; and the extended-spectrum penicillins (azlocillin, carbenicillin, mezlocillin, piperacillin and ticarcillin), which are effective against gram-positive and gram-negative organisms, including Pseudomonas aeruginosa. Allergic reaction to penicillin occurs in some animals. The reaction may be slight—a stinging or burning sensation at the site of injection—or it can be more serious—severe dermatitis or even anaphylactic shock, which may be fatal.
penicillin allergydegradation products of the penicillins act as haptens, binding to proteins and stimulating an immune response. penicillin Gbenzylpenicillin; the most widely used penicillin; used principally in the treatment of infections due to gram-positive bacteria. Procaine penicillin G is a parenteral preparation that gives extended action for up to 24 hours and benzathine penicillin G is a very slow-release, parenteral preparation that maintains blood levels for several days. penicillin-induced hemolytic anemiarare problem in horses which develop IgG anti-penicillin antibodies. phenoxymethyl penicillina biosynthetically or semisynthetically produced antibiotic, similar to penicillin G, for oral administration; not affected by gastric acid and is suitable for oral administration. Its antibacterial spectrum is the same as for penicillin G. Called also penicillin V. penicillin Vsee phenoxymethyl penicillin (above).
antibiotic 1. Pertaining to the ability to destroy or inhibit other living organisms. 2. A substance derived from a mould or bacterium, or produced synthetically, that destroys (bactericidal) or inhibits the growth (bacteriostatic) of other microorganisms and is thus used to treat infections. Some substances have a narrow spectrum of activity whereas others act against a wide range of both gram-positive and gram-negative organisms ( broad-spectrum antibiotics). Antibiotics can be classified into several groups according to their mode of action on or within bacteria: (1) Drugs inhibiting bacterial cell wall synthesis, such as bacitracin, vancomycin and the β-lactams based agents (e.g. penicillin, cephalosporins (e.g. ceftazidime, ceftriaxone, cefuroxime). (2) Drugs affecting the bacterial cytoplasmic membrane, such as polymyxin B sulfate and gramicidin. (3) Drugs inhibiting bacterial protein synthesis, such as aminoglycosides (e.g. amikacin sulfate, framycetin sulfate, gentamicin, neomycin sulfate and tobramycin), tetracyclines, macrolides (e.g. erythromycin and azithromycin) and chloramphenicol. (4) Drugs inhibiting the intermediate metabolism of bacteria, such as sulfonamides (e.g. sulfacetamide sodium) and trimethoprim. (5) Drugs inhibiting bacterial DNA synthesis, such as nalixidic acid and fluoroquinolones (e.g. ciprofloxacin, levofloxacin, moxifloxacin, norfloxacin and ofloxacin). (6) Other antibiotics such as fusidic acid, the diamidines, such as propamidine isethionate and dibrompropamidine. Syn. antibacterial. See antiinflammatory drug; fusidic acid.
piperacillin sodiumPharmacologic class: Penicillin (extended-spectrum) Therapeutic class: Anti-infective Pregnancy risk category B ActionInhibits bacterial cell-wall synthesis during active multiplication stage, resulting in cell death AvailabilityInjection: 2 g, 3 g, 4 g, 40 g ⊘Indications and dosages ➣ To prevent infection during abdominal and vaginal surgery Adults: For intra-abdominal surgery, 2 g I.V. just before surgery, followed by 2 g during surgery, then 2 g q 6 hours postoperatively for no more than 24 hours. For vaginal hysterectomy, 2 g I.V. just before surgery, followed by 2 g at 6 hours and 2 g at 12 hours after the initial dose. In cesarean delivery, 2 g I.V. after umbilical cord is clamped, followed by 2 g at 4 hours and 2 g at 8 hours after the initial dose. In abdominal hysterectomy, 2 g I.V. just before surgery, followed by 2 g on return to recovery room and 2 g 6 hours later. ➣ Serious infections Adults: 12 to 18 g/day I.V. in divided doses q 4 to 6 hours ➣ Complicated urinary tract infection (UTI) Adults: 8 to 16 g/day I.V. in divided doses q 6 to 8 hours ➣ Uncomplicated UTI or community-acquired pneumonia Adults: 6 to 8 g/day I.M. or I.V. in divided doses q 6 to 12 hours ➣ Uncomplicated gonorrhea Adults: 2 g I.M. as a single dose, with 1 g probenecid P.O. given 30 minutes before piperacillin injection Dosage adjustment• Renal impairment
• Elderly patients
• Children Contraindications• Hypersensitivity to penicillin or cephalosporins PrecautionsUse cautiously in:
• uremia, hypokalemia, cystic fibrosis, bleeding tendencies, drug allergies, sodium restriction
• pregnant or breastfeeding patients
• children younger than age 12. Administration• Ask patient about allergy to penicillin and cephalosporins before administering.
☞ Keep epinephrine and emergency equipment available.
• For I.M. use, dilute in sterile water for injection or normal saline solution, to yield a final concentration of 400 mg/ml. Limit dosage to 2 g. Preferably, inject into upper outer buttock area.
• For intermittent I.V. infusion, dilute reconstituted solution in 50 ml of dextrose 5% in water, normal saline solution, dextrose 5% in normal saline solution, or lactated Ringer's solution. Infuse over 20 to 30 minutes.
• When giving I.V. bolus, inject reconstituted solution over 3 to 5 minutes.
• Don't mix with aminoglycosides in syringe or infusion container; doing so inactivates aminoglycoside. | Route | Onset | Peak | Duration | | I.V. | Immediate | Immediate | Dose dependent | | I.M. | Unknown | 30-50 min | Dose dependent |
Adverse reactionsCNS: headache, dizziness, fatigue, seizures CV: thrombophlebitis, deep-vein thrombosis GI: nausea, vomiting, constipation, diarrhea, bloody diarrhea, pseudomembranous colitis Hematologic: hematoma, eosinophilia, neutropenia, leukopenia, thrombocytopenia Hepatic: cholestatic hepatitis Metabolic: hypokalemia, hypernatremia, sodium overload Skin: rash, erythema, induration, bruising, erythema multiforme, Stevens-Johnson syndrome Other: pain, superinfection, anaphylaxis InteractionsDrug-drug. Aminoglycosides: aminoglycoside inactivation Aspirin, probenecid: increased piperacillin blood level Hormonal contraceptives: decreased contraceptive efficacy Methotrexate: increased risk of methotrexate toxicity Tetracyclines: decreased piperacillin efficacy Vecuronium: prolonged neuromuscular blockade Drug-diagnostic tests. Bilirubin, blood urea nitrogen, creatinine, eosinophils, hepatic enzymes: increased values Coombs' test (with I.V. piperacillin): false-positive result Granulocytes, hemoglobin, platelets, white blood cells: decreased levels Patient monitoring☞ Monitor for signs and symptoms of anaphylaxis or superinfection.
☞ Be aware that high doses may cause seizures.
☞ Watch for signs and symptoms of thrombophlebitis and deep-vein thrombosis.
• Assess drug efficacy. Obtain repeat cultures after therapy ends.
☞ Monitor potassium level and CBC with white cell differential. Check for blood dyscrasias and hypokalemia.
☞ Assess for signs and symptoms of erythema multiforme (sore throat, rash, cough, iris lesions, mouth sores, cough, fever). Report early signs before condition can progress to Stevens-Johnson syndrome. Patient teaching• Stress importance of completing entire course of therapy.
☞ Instruct patient to immediately report allergic reactions, rash, or severe diarrhea.
• Instruct patient to contact prescriber if signs and symptoms of infection worsen or if new symptoms develop.
• Advise female patient taking hormonal contraceptives to use alternate birth-control method.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.
penicillin Infectious disease An antibiotic that inhibits crosslinking of peptidoglycan chains in bacterial cell walls; bacteria growing in penicillin synthesize weak cell walls, causing them to burst due to the high osmotic pressure. Cf
Ampicillin.
Patient discussion about Peniciline. Q. is it possible to drink alcohol during taking penicillin antibiotic? A. i know that it's probably bad to take antibiotics with alcohol but couldn't remember why. so i looked you question up until i found a Doctor's answer to it-
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