Comparative Pharmacokinetics of Theophylline in Camels (<i>Camelus dromedarius</i>) and Goats (<i>Caprus hircus</i>)

Elsheikh, Hatim Ali; Ali, Badreldin H.; Zahurin, M.; Mohd, Mustafa Ali; Alhadrami, Ghaleb; Bashir, A. K.

doi:10.1046/j.1439-0442.2001.00401.x

Cited by 5 publications

(2 citation statements)

References 16 publications

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“…After a one-month washout period to ensure clearance of goat's bodies from any drug residues, goats were injected intramuscularly into thigh muscles with theophylline (2 mg/kg b.wt. once daily) [30] for seven consecutive days then tylosin was injected two hours after the last theophylline injection in the same previous protocol.…”

Section: Experimental Designmentioning

confidence: 99%

The Effect of Theophylline on Serum and Milk Pharmacokinetics of Tylosin Following Intramuscular Administration in Lactating Goats

EL-Tareef,

Abo-EL-Sooud,

Karmi

et al. 2023

Preprint

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Aim of the work: This study was conducted to evaluate the influence of theophylline pre-treatment on the pharmacokinetic and milk elimination of tylosin following single intramuscular (IM) administrations in lactating goats as an example of an antibacterial and bronchodilator combination that frequently used in veterinary medicine to control respiratory diseases. Methods and results In a cross-over study, tylosin was injected intramuscularly at a single dose of 15 mg/kg b.wt. After a one-month washout period goats received theophylline at a daily IM dose of 2 mg/kg b.wt. for seven consecutive days then tylosin was injected two hours after the last theophylline injection as the same previous treatment. Blood samples were collected before and at 0.25, 0.5, 0.75, 1, 2, 4, 6, 8, 10, 12, and 24 h post-injection. Samples were left to clot and then centrifuged to yield sera, Milk samples were collected before and at 0.5, 1, 2, 4, 6, 8, 10, 12, 24, 48, and 72h post-injection from each goat by hand milking. Tylosin serum concentrations were determined by high-performance liquid chromatography (HPLC). Tylosin concentrations versus time were analyzed by a noncompartmental method. Theophylline significantly decreased tylosin concentrations as the Cmax declined from 1.728 ± 0.100 to 1.014 ± 0.113 µg/ml, and attained Tmax values of 2 and 1 h, respectively. Moreover, theophylline pretreatment significantly shortened the elimination half-life (t1/2el) from 6.934 to 1.973 h, t1/2ka from 0.621 to 0.359 h and the mean residence time (MRT) from 8.022 to 4.312 h, also Vz/F and AUCs decreased from 11.913 to 7.702 L/Kg and from 12.641 to 4.567µg*h/ml, respectively, consequently, theophylline enhanced the clearance (Cl/F) of tylosin from the body. Similarly, tylosin milk concentrations were significantly lower in theophylline-pretreated goats than in goats that received tylosin alone. Moreover, the t1/2el and AUCs were significantly decreased from 14.684 ± 1.973 to 27 4.720 ± 0.477 h, and from 181.003 to 67.171 µg*h/ml, respectively. Conclusions We concluded that when tylosin is administrated after theophylline pretreatment, its concentrations may fall to subtherapeutic levels, which could have serious clinical consequences.

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Section: Experimental Designmentioning

confidence: 99%

The Effect of Theophylline on Serum and Milk Pharmacokinetics of Tylosin Following Intramuscular Administration in Lactating Goats

EL-Tareef,

Abo-EL-Sooud,

Karmi

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…Thus, it is of great interest to develop methods for rapid and highly selective theophylline detection. Moreover, theophylline is an established "probe drug" to evaluate the drug metabolising enzyme activity of both man and animals (Elsheikh, et al, 2001) thus making it a key analyte in pharmaceutical studies.…”

Section: Introductionmentioning

confidence: 99%