Amoxicillin Milk

Aspirin is avoided in breast-feeding because of the possibility of Reye s syndrome. Moreover if high doses of aspirin are used, the neonate may develop hypoprothrombinaemia. Benzodiazepines such as diazepam are present in milk and therefore should be avoided during breast-feeding. Amoxicillin can be safely administered during pregnancy and breast-feeding. 

Amoxicillin is widely distributed in body tissues and its metabolism is limited. Excretion of amoxicillin is tlirough the kidney, resulting in high concentrations in both the kidney tissue and urine, where the levels may be 100-fold higher than that in serum. Concentrations in milk are 10 times lower than those in serum. Following intramuscular or subcutaneous injection to goats, levels of amoxicillin in milk were very close to the detection limit of 10 ppb within 24 h after the last dose (65). 

Fluorometric detection has been mainly employed for the determination of aminopenicillins such as amoxicillin and ampicillin in edible animal products because it confers the advantages of selectivity and sensitivity. Fluorometric detection of penicillins, however, necessitates their precolumn derivatization to produce the corresponding fluorescent derivatives. The most commonly used derivatizing reagents are formaldehyde (100, 117, 118), salicylaldehyde (83), and mercury dichloride (91). 4-Bromomethyl-7-methoxycoumarin has also been employed as a fluorescence label for the selective and sensitive detection of seven penicillins in milk (96). 

Straub et al. (76) reported a method for the identification and quantification of penicillin G, ampicillin, amoxicillin, cephapirin, cloxacillin, and ceftiofur residues in milk using perfusive-particle liquid chromatography combined with ultrasonic nebulization electrospray mass spectrometry. According to this method, a 0.5 ml milk sample is diluted with an equal volume of a solution consisting of acetonitrile/water (1 1), and ultrafiltrated in a microseparation system with a 10000 da molecular mass cut-off filter. An aliquot of the ultrafiltrate is then analyzed on a 15 cm porous II R/H LC (7-8 m) perfusion analytical column using the chromatographic conditions shown in Table 29.3. Concentrations as low as 10 ppb could be readily determined in milk by electrospray mass spectrometric detection. 

Lactamase Inhibitor] Uses Ear, lower resp, sinus, UTI, skin Infxns caused by i-lactamase-producing H. influenzae, S. aureus, E. coli Action Combo 3-lac-tam antibiotic i-lactamase inhibitor Dose Adults. 250-500 mg PO q8h or 875 mg ql2h XR 2000 mg PO ql2h Peds. 20-40 mg/kg/d as amoxicillin PO q8h or 45 mg/kg/d + ql2h X in renal impair take w/ food Caution [B, enters breast milk] Disp Tabs, chew tabs, susp SE Abd discomfort, N/V/D, allergic Rxn, vaginitis Notes Do not substitute two 250-mg tabs for one 500-mg tab (OD of clavulanic acid) max clavulanic acid 125 mg/dose Interactions T Effects OF warfarin, MTX,... 

WA Moats. Determination of ampicillin and amoxicillin in milk with an automated liquid-chromatographic cleanup. J AOAC Int 77 41-45, 1994. 

WH Luo, EB Hansen, CYW Ang, J Deck, JP Freeman, HC Thompson. Simultaneous determination of amoxicillin and ampicillin in bovine milk by HPLC with fluorescence detection. J Agr Food Chem 45 1264-1268, 1997. 

CYW Ang, WH Luo, VL Call, HF Righter. Comparison of liquid chromatography with microbial inhibition assay for determination of incurred amoxicillin and ampicillin residues in milk. J Agr Food Chem 45 4351-4356, 1997. 

Salter, R.S., D. Legg, N. Ossanna, et al. 2001. Charm safe-level 3-lactam test for amoxicillin, ampicillin, ceftiofur, cephapirin, and penicillin G in raw commingled milk. J. AOAC Int. 84 29-36. 

An enzyme linked immunosorbent assay (ELISA) has been developed and applied to assay of amoxicillin in lung secretions in comparison with conventional bioassay [182]. The ELISA was capable of measuring amoxicillin down to 10 ng/ml, but it also responded to amoxicillin penicilloic acid and consequently gave results higher than bioassay. A commercially available ELISA system was reported to have a sensitivity of 6 ng/ml for amoxicillin in milk [183],... 

Penicillins Pharmaceuticals, milk Methylene blue grafted polyurethane foam UV-Vis 12,15,19 ng mL-1 for penicillin G, amoxicillin, ampicillin Flow injection system with a mini-column at the injection port [505]... 

Moats, W.A. Determination of ampicUhn emd amoxicillin in milk with an automated hquid chromatographic cleanup. JAOACInt., 1994, 77,41—45 [milk extracted ampiciUin, cephapirin gradient LOQ 10 ppb]... 

Straub, R. Linder, M. Voyksner, R.D. Determination of p-lactam residues in milk using perfusive-particle liquid chromatography combined with ultrasonic nebulization electrospray mass spectrometry. AreoZ. Chew., 1994, 66, 3651-3658 [milk electrospray LC-MS microbore LOD 10 ppb extracted amoxicillin, ceftiofur, cephapirin, cloxacillin, penicillin G]... 

Straub, R.F. Voyksner, R.D. Determination of penicillin G, ampicillin, amoxicillin, cloxacillin and cephapirin by high-performance liquid chromatography-electrospray mass spectrometry. J. Chromatogr., 1993, 647, 167-181 [milk extracted amoxicillin, cephapirin, cloxacillin, penicillin G LC-MS electrospray UV detection LOD 100 ppb]... 

Co-amoxiclav (amoxicillin 500 mg with clavulanic acid 250 mg) was given to 16 healthy subjects at the same time as the second offour 200-mL glasses of milk (taken at 20 minute intervals). Although the bioavailability of the amoxicillin and clavulanic acid tended to be decreased, and the time to peak levels delayed, the changes did not reach statistical significance. No special precautions would seem to be necessary. 

Antibiotics The AOAC has listed methods for sulfamethazine residues in swine tissues with determination either by GC-MS or GC-ECD of methylated derivatives and for sulfamethazine (and for the class of sulfonamides) in milk with determination by HPLC-UV. There is an AOAC method for the class of sulfonamide antimicrobials in animal tissues using solvent extraction and liquid partitioning with determination by TLC and fluorimetric scanning. For analysis of tetracyclines, AOAC describes methods based on buffer extraction from tissue samples and SPE (Cis) cleanup, or metal chelate affinity binding from milk samples, with determination in both cases by HPLC-UV. USDA/FSIS methods include (1) a method (similar to the AOAC GC-MS method for sulfamethazine) for confirmation of sulfonamide residues in edible tissues using solvent extraction and multiple liquid partitioning with determination of the methylated derivatives by GC-MS (2) methods for determination and confirmation of chloramphenicol in muscle by solvent extraction, liquid partitioning, and determination of the trimethylsilane (TMS) derivative by GC-ECD and GC-MS, respectively and (3) a method for determination of the beta-lactam antibiotic amoxicillin by aqueous extraction, cleanup by tricarboxylic acid precipitation, and ether extraction and formation of a fluorescent derivative for determination by LC. 

Penicillin G, procaine, amoxicillin, cloxacillin, ampicillin, cephapirin, and ceftiofur were extracted from milk and baseline resolved on a 40°C phenyl... 

Desacetylcephapirin was extracted from milk samples and quantitated using a PLRP-S column (A = 290 nm) using a 16/84 acetonitrile/water (10 mM H3PO4 with lOmM KH2PO4 and lOmM sodium decanesulfonate) mobile phase [1379], This study also tabulated the conditions for the analysis of amoxicillin, ampicillin, cephapirin, ceftiofur, cloxacillin, and penicillins G and V. Again a C,g and an 30% acetonitrile/water (phosphate buffer) combination were used in each case. 

Liquid chromatography-electrospray-mass spectrometry has been successfully used for the multiresidue assay of penicilhn G, ampicilhn, amoxicillin, cloxaciUin, and cephapirin in milk ultrafiltrate at the 100-ppb level after postcolumn splitting of the eluent and recording under SIM conditions in the positive-ion modeJ Significantly tissuesJ lower detection limits were reported by other workers who described an LC-ESP-MS confirmatory procedure for the simultaneous determination of five penicillins in milk and meat under SIM conditions in the negative-ion modeJ ... 

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