Publications

Export 9 results:
Sort by: [ Author  (Asc)] Title Type Year
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 
A
Disposition of tylosin in goats., Atef, M., Youssef S. A., Atta A. H., and El-Maaz AA , DTW. Deutsche tierarztliche Wochenschrift, 1991 Dec, Volume 98, Issue 12, p.451-3, (1991) Abstract

The disposition kinetics of tylosin was studied in goats after intravenous or intramuscular injection of 15 mg/kg b. wt. Following i.v. injection, tylosin was rapidly and widely distributed in goats (half life of distribution: 0.2 h and volume of distribution: 1.7 l/kg). It was slowly eliminated with a mean elimination half life of 3.04 h and a total body clearance rate of 6.8 ml/kg/min. Following i.m. injection, tylosin was slowly absorbed (T1/2ab of 1.82 h). Tylosin concentration in serum was greater than 1 microgram/ml after 1 h and persisted up to 12 h post-injection. The peak concentration (Cmax, 2.38 micrograms/ml) was obtained after 4.19 h. The systemic bioavailability of tylosin injected intramuscularly was 72.6% and the serum protein bound fraction was 37.6% of the total drug. Tylosin was excreted in milk and urine at concentrations much higher than that in serum. Low concentrations of tylosin were reported in ruminal juice of goats. In conclusion tylosin should be injected every 15 hours to obtain an appreciable concentration in serum, milk and urine.

Influence of E. coli infection on the disposition kinetic of nalidixic acid in broiler chickens., Atef, M., Youssef S. A., Amer AM, and El-Banna H. A. , DTW. Deutsche tierarztliche Wochenschrift, 1992 Apr, Volume 99, Issue 4, p.140-3, (1992) Abstract

The pharmacokinetic data of nalidixic acid were investigated in normal and E. coli infected chickens. The highest serum concentration were reached after 2 hours with t0.5 (ab) of (1.706 +/- 0.1 min in normal and 2.030 +/- 0.11 min in diseased) and (1.72 +/- 0.11 min in normal and 1.416 +/- 0.044 in diseased chickens) following oral and intramuscular administration, respectively. The elimination half-life t0.5 (beta) were (2.514 in normal and 2.35 hr in diseased) and (2.567 hr in normal and 2.672 hr in diseased) respectively. Following intravenous injection the kinetic of nalidixic acid followed two compartments open model with t0.5 of (6.27 and 9.15 hr), Vd (0.45 and 0.79 L/kg), Cltot (8.86 and 13.32 ml/kg/min) in normal and E. coli infected chickens, respectively. Administration of nalidixic acid twice daily for 5 successive days in a dose level of 25 mg/kg b. wt. by oral and intramuscular routes showed a cumulative behaviour.

Pharmacokinetic properties of florfenicol in Egyptian goats., Atef, M., El-Gendi AY, Aziza MM, and Abd El-Aty A. M. , DTW. Deutsche tierarztliche Wochenschrift, 2000 Apr, Volume 107, Issue 4, p.147-50, (2000) Abstract

The single-dose disposition kinetics of florfenicol was determined in healthy, non-lactating Egyptian goats, after its intravenous (i.v.) and intramuscular (i.m.) administration at 20 mg kg-1 b.wt. Drug concentrations in serum and urine were determined using microbiological assay method and data was subjected to a kinetic analysis. Florfenicol concentrations in serum decreased in a bi-exponential manner after intravenous administration with distribution (t1/2 alpha) and elimination (t1/2 beta) half-lives of 10.256 +/- 0.938 and 56.237 +/- 3.102 minute, respectively. The steady-state volume of distribution (Vdss) and total body clearance (Cltot) were 3.413 +/- 0.304 l kg-1 and 3.306 +/- 0.333 l kg h-1. After intramuscular administration, the peak serum concentration (Cmax) was 0.859 +/- 0.025 micrograms ml-1, achieved at (Tmax) 1.220 + 0.045 h. Florfenicol was detected in urine up to 24 and 96 hour after i.v. and i.m. administration, respectively. The extent of the protein binding and systemic bioavailability of florfenicol were 22.45 +/- 1.727% and 65.718 +/- 3.372%, respectively.

Influence of aflatoxin B1 on the kinetic disposition, systemic bioavailability and tissue residues of doxycycline in chickens., Atef, M., Youssef S. A. H., El-Eanna HA, and El-Maaz AA , British poultry science, 2002 Sep, Volume 43, Issue 4, p.528-32, (2002) Abstract

1. Disposition kinetics of doxycycline (doxy) was studied in healthy chickens and chickens experimentally intoxicated with aflatoxin B1 by intravenous, oral or intramuscular (i.m.) injection, in a single dose of 15 mg/kg body weight. In addition, the tissue distribution and residual pattern of the drug were determined in healthy and intoxicated chickens. 2. The maximum serum concentrations of doxy were reached 1.97 and 2.37 h after oral, and 1.57 and 2.92 h after i.m. dosage in healthy and aflatoxic birds, respectively. 3. The volumes of distribution and total body clearances were higher in aflatoxic birds (1.75 l/kg and 14.61 ml/kg/min) than in healthy chickens (0.93 l/kg and 4.6 ml/kg/min). Data relating to intravenous injection were analysed using a two-compartment open model curve fit. 4. Lower values of systemic bioavailability were observed in intoxicated birds (30.9 and 33.9%) than healthy ones (43.7 and 57.3%) after oral and i.m. administration, respectively. 5. The highest concentration of doxy residues were present in liver, kidney and serum followed by heart and muscles. Doxy residue concentrations in edible tissues was below the EEC limit 6 d after cessation of oral or i.m. medication with 15 mg/kg body weight twice daily for 5 successive days.

Pharmacokinetics aspects and tissue residues of Marbofloxacin in healthy and Mycoplasma gallisepticum–infected chickens, Atef, M., A.H. Atta, Darwish A., and Ahmed G. M. , Wulfenia Journal, Volume 24, Issue 10, p.80-107, (2017)
Kinetic disposition, systemic bioavailability and tissue distribution of salinomycin in chickens., Atef, M., Ramadan A., Youssef S. A., and Abo El-Sooud K. , Research in veterinary science, 1993 Mar, Volume 54, Issue 2, p.179-83, (1993) Abstract

Salinomycin was administered to chickens orally and intravenously to determine blood concentration, kinetic behaviour, bioavailability and tissue residues. The drug was given by intracrop and intravenous routes in a single dose of 20 mg kg-1 body-weight. The highest serum concentrations of salinomycin were reached half an hour after oral dosage with an absorption half-life (t0.5(ab)) of 3.64 hours and elimination half-life (t0.5(beta)) of 1.96 hours. The systemic bioavailability percentage was 73.02 per cent after intracrop administration, indicating the high extent of salinomycin absorption from this route in chickens. Following intravenous injection the kinetics of salinomycin can be described by a two-compartment open model with a t1/2(alpha) of 0.48 hours, Vd ss (volume of distribution) of 3.28 litre kg-1 and Cl(beta) (total body clearance) of 27.39 ml kg-1 min-1. The serum protein-binding tendency of salinomycin as calculated in vitro was 19.78 per cent. Salinomycin concentrations in the serum and tissues of birds administered salinomycin premix (60 ppm) for two weeks were lower than those after administration of a single intracrop dose of pure salinomycin (20 mg kg-1 bodyweight). The highest concentration of salinomycin residues were present in the liver followed by the kidneys, muscles, fat, heart and skin. No salinomycin residues were detected in tissues after 48 hours except in the liver and these had disappeared completely by 72 hours.

Pharmacokinetics of chloramphenicol in normal and Escherichia coli infected chickens., Atef, M., Atta H., and Amer AM , British poultry science, 1991 Jul, Volume 32, Issue 3, p.589-96, (1991) Abstract

1. Disposition kinetics were compared in healthy chickens and in chickens naturally infected with E. coli following the intravenous, intramuscular and oral administration of chloramphenicol in a single dose of 20 mg/kg body weight. 2. Lower serum chloramphenicol concentration in diseased chickens were reported after intravenous injection, but they were higher than normal 30 min after intramuscular and oral administration. Following intravenous injection the volume of distribution was increased in diseased chickens. 3. The biological half-life in normal chickens was 8.32 +/- 0.5 h and was prolonged in diseased birds (26.21 +/- 0.2 h). The body clearance of chloramphenicol was reduced in diseased chickens. 4. The rate of absorption of chloramphenicol was delayed after administration via the oral route but the extent of absorption was increased. The maximum concentration was higher and it was reached after a longer time in diseased than in normal chickens after administration by both intramuscular and oral routes.

Effect of flunixin on the disposition kinetics of florfenicol in goats, Atef, M., El-Gendi AY, El-Zorba H. Y., Atta Attia. H., and Ibrahem Sheren I. , Wulfenia Journal, Volume 25, Issue 10, p.37-52, (2018)
H
Pharmacokinetics and tissue residues of kitasamycin in healthy and diseased broilers., Hassan, A. B., Atta A. H., and Soliman Z. I. , DTW. Deutsche tierarztliche Wochenschrift, 1990 Aug, Volume 97, Issue 8, p.315-7, (1990) Abstract

The pharmacokinetics of kitasamycin after intravenous and oral administration in a dose of 300 mg/kg b.wt. was studied in 18 healthy and 18 Salmonella gallinarum naturally infected chickens. The tissue residue of the studied antibiotic was estimated in 36 normal chickens when it was given orally for 7 successive days. Therapeutic level of kitasamycin was achieved after 15 minutes and persisted for 20-22 hours after its oral administration. Higher serum kitasamycin concentrations were recorded in Salmonella gallinarum infected chickens. The elimination half-life of kitasamycin calculated after single intravenous injection was 9.03 hours in diseased chickens corresponding to 3.74 hours in healthy birds. The body clearance was significantly reduced in diseased chickens (23.86 ml/kg/min) when compared to that in normal ones (62.03 ml/kg/min). Kitasamycin treated broilers should not be slaughtered before 3 days from the last dose as it was detected only in bile and caecum at that time but not in edible tissues.