Penicillins oxacillin

Penicillins. This group includes penicillin G (benzyl-penicillin), penicillin VK (phenoxymethyl-penicillin), the isoxazolyl penicillins oxacillin, cloxacillin, dicloxacillin and nafcillin, the amino-penicillins ampicillin, hetacillin and amoxycillin, the carboxy-penicil-lin carbenicillin, and the thienyl-penicillin ticarcillin. 

Nafcillin and the isoxazolyl penicillins (oxacillin, cloxacillin, dicloxacillin). 

Semi-Synthetic PenicriiInase-Resistant Oral Penicillins Oxacillin (X = Y = H) Baclocil ... 

The pharmacology of penicillins differs markedly from compound to compound but has been well reviewed (57). The majority of derivatives, including penicillin G and the antipseudomonal penicillins, ate unstable in gastric acid and ate not available orally. The isoxazolyl penicillins ate relatively acid stable but not consistendy well absorbed by the oral route. Nafcillin and oxacillin ate poody absorbed orally cloxacillin, dicloxacillin, and ducloxacillin ate more teUable. Penicillin V, ampicillin, and patticulady amoxicillin ate relatively well absorbed orally. Esters of ampicillin such as bacampicillin, pivampicillin, and talampicillin improve the level of oral absorption of ampicillin to that achieved by amoxicillin. Absorption can be diminished by food after oral adruinistration, however, and peak blood levels, usually achieved after 1 to 2 h, ate somewhat delayed after ingestion of food. 

Epicillln Floxaclllin Methicillin sodium Nafcillin sodium Oxacillin sodium Penicillin V... 

Warfarin sodium Benzal acetophenone Alkofanone Benzaldehyde Butalamlne HCI Chloramphenicol Fenipentol Isocarboxazid Oxacillin sodium Penicillin G benzathine Phenylpropanolamine HCI Tripelennamine Benzaldehyde cyanohydrin Ethotoin... 

Class D enzymes (Mr of about 27,000) exhibit a high activity versus isoxazolyl penicillins, such as oxacillin and are referred to as the OXA-family. Surprisingly, the amino group of the SXXK lysine residues is carboxylated in the most active forms of the enzymes. Penicillins are generally better substrates than cephalosporins but mutations have been found which confer extended activity spectra to these enzymes. 

Penicillin derivatives and cephalosporins e.g. penicillic acid, oxacillin, clonacillin,... 

It is important to determine (1) whether the isolate is methicillin-susceptible or methicillin-resistant and (2) whether the patient has a prosthetic valve. For patients with no prosthetic material, methicillin-susceptible staphylococci treatment should consist of a penicillinase-resistant penicillin (e.g., nafcillin or oxacillin) with or without gentamicin, and for methicillin-resistant strains, therapy should consist of vancomycin (see Table 71-4). Combination therapy with aminoglycosides, when used in these patients, typically is given only during the first 3 to 5 days of therapy. In the absence of prosthetic material, some treatment guidelines do not recommend combination therapy against MRSA. However, many clinicians may combine either gentamicin or rifampin with vancomycin if the patient is unresponsive to monotherapy. 

For penicillin-allergic (nonanaphylactoid type) patients cefazolin 6 g/24 hours IV in 3 equally divided doses 6 IB Consider skin testing for oxacillin-susceptible staphylococci and questionable history of immediate-type hypersensitivity to penicillin cephalosporins should be avoided in patients with anaphylactoid-type hypersensitivity to P-lactams vancomycin should be used in these cases ... 

Penicillin C 24 million units/24 hours IV in 4 to 6 equally divided doses may be used in place of nafcillin or oxacillin if strain is penicillin-susceptible (minimum inhibitory concentration less than or equal to 0.1 mcg/mL) and does not produce P-lactamase. cGentamicin should be administered in close temporal proximity to vancomycin, nafcillin, or oxacillin dosing. 

It was recognized quite some time ago that DTA analysis could be used to deduce the compatibility between a drug substance and its excipients in a formulation. The effect of lubricants on performance was as problematic then as it is now, and DTA proved to be a powerful method in the evaluation of possible incompatibilities. Jacobson and Reier used DTA to study the interaction between various penicillins and stearic acid [17]. For instance, the addition of 5% stearic acid to sodium oxacillin monohydrate completely obliterated the thermal events associated with the antibiotic. Since that time, many workers employed DTA analysis in the study of drug-excipient interactions, although the DTA method has been largely replaced by differential scanning calorimetry technology. 

The answer is a. (Hardman, pp 1143-1144.) Polymyxin B is poorly absorbed by the oral route. It is primarily administered by the topical route for the treatment of infections of the skin, mucous membranes, eye, and ear. Penicillin G can be administered both orally and parenterally. Did oxacillin is only given by the oral route. Carbenicillin and streptomycin are administered only by the parenteral route. 

The answer is b. (Hardman, p 1077.) Unlike the other listed drugs, oxacillin is resistant to penicillinase. The other four agents are broad-spectrum penicillins, while oxacillin is generally specific for Gram-positive microorganisms Use of penicillinase-resistant penicillins should be resewed for infections caused by penicillinase-producing staphylococci... 

The answer is b. (Hardman, p 1077.) Oxacillin is classified as a penicillinase-resistant penicillin that is relatively acid-stable and, therefore, is useful for oral administration. Major adverse reactions include penicillin hypersensitivity and interstitial nephritis. With the exception of methi-cillin, which is 35% bound to serum proteins, all penicillinase-resistant penicillins are highly bound to plasma proteins. Oxacillin has a very narrow spectrum and is used primarily as an anti staphylococcal agent... 

BLIC, /5-lactamase inhibitor combination BL/BLI, jS-lactamase/jS-lactamase inhibitor FGC, first-generation cephalosporin MIC, minimal inhibitory concentration PRP, penicillinase-resistant penicillin SGC, second-generation cephalosporin TGC, third-generation cephalosporin. Penicillinase-resistant penicillin nafcillin or oxacillin. 

Macrolide/azalide erythromycin, clarithromydn-azithromycin. femisynthetic penicillin nafcillin, oxacillin. 

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). 

To our knowledge only one work has been reported on the use of a commercial immunochemical test to detect penicillins (penicillin G, penicillin V, ampicillin, cloxacillin, and oxacillin) in several environmental compartments. Thus, Campagnolo et al. [84] measured penicillin using the Charm IIRIA test in water samples proximal to a US farm. The LOD of the technique was 2 pg L L... 

An interesting example of MIP-LC analytics was presented in a paper, which focused on the separation of antibiotics of similar structures. Columns are (commercially) available to separate penicillins ( 3-lactams) from other antibiotics. However, if the quantification of each of the 3-lactam compounds is required, a more selective stationary phase has to be found. Molecular imprinting allows the fabrication of phases specifically for each 3-lactam. If for instance the concentration of the P-lactam oxacillin in a food sample has to be selectively determined, a polymer imprinted with oxacillin is the right choice. Compared to a standard stationary phase, which only allowed the separation of the entire group of (5-lactams from other non-(3-lactam analytes (e. g., bacitracin), the MIP enables the separation of the imprinted species from the pair of non-imprinted 3-lactams penicillin V and penicillin G see Fig. 6 [29,30]. 

Fig. 6. A Chromatogram of a mixture containing the print molecule (oxacillin), two other p-lactam-antibiotics (penicillin G and penicillin V) and a non- 3-lactam-antibiotic (bacitracin) on an oxacillin imprinted MIP containing 4-vinylpyridine residues, cross-linked with TRIM. The analysis was performed in organic mobile phase (ACN/AcOH,99 l).B Same conditions but using the respective non-imprinted control polymer. C Structures of penicillin V, penicillin G, and oxacillin. Reprinted with permission from Skudar K, Briiggemann O, Wittelsberger A, Ramstrom O (1999) Anal Commun 36 327. Copyright 1999 The Royal Society of Chemistry...

First generation Examples are penicillin G (only natural penicillin in clinical use), penicillin V and fylactamase resistant penicillins like methi-cillin, nafcillin, oxacillin, cloxacillin, floxacillin etc. 

Another type of semisynthetic penicillins that are considered heteroylcarboxylic acid derivatives, in which the acyl group is represented as an aromatic heterocyclic acid derivative (oxacillin, cloxacillin, dicoxacillin). 

Another type of semisynthetic penicillin that should undoubtedly be considered is penicillin derivatives of heteroylcarboxylic acids (as a rule an isoxazol) in the third position of which is present a substituted or nonsubstituted phenyl radical (oxacillin, cloxacilhn, dicloxaciUin), which plays the role of the radical in the acyl side group. These penicillins (oxacilhn, cloxacilhn, dicloxacilhn), which are resistant to penicillinase, are active with respect to peniciUin-G-resistant staphylococci. Their antimicrobial spectrum is restricted to Gram-positive microorganisms. 

Excretion - Penicillins are excreted largely unchanged in the urine by glomerular filtration and active tubular secretion. Nonrenal elimination includes hepatic inactivation and excretion in bile this is only a minor route for all penicillins except nafcillin and oxacillin. Excretion by renal tubular secretion can be delayed by coadministration of probenecid. Elimination half-life of most penicillins is short (no... 

Lab test abnormalities Elevations of AST, ALT, bilirubin, and LDH have been noted in patients receiving semisynthetic penicillins (particularly oxacillin) such reactions are more common in infants. Elevations of serum alkaline phosphatase and hypernatremia and reduction in serum potassium, albumin, total proteins, and uric acid may occur. 

Oxacillin (Bactocill, Prostaphlin) [Antibiotic/Penicillin] Uses ... 

Nafcillin, oxacillin, cloxacillin, and dicloxacillin are more resistant to bacterial (3-lactamases than is penicillin G. Consequently, these antibiotics are effective against streptococci and most community-acquired penicillinase-producing staphylococci. Methicillin, which is no longer marketed in the United States, is another penicillinase-resistant antibiotic similar to nafcillin and oxacillin. For historical reasons, staphylococci resistant to oxacillin or nafcillin are labeled methicillin resistant. Many hospitals are reservoirs for MRSA and methi-cillin-resistant Staphylococcus epidermidis (MRSE). These nosocomial pathogens are resistant in vitro to all (3-lactam antibiotics. 

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