Biomaterial Database

Factors affecting aminoglycoside disposition: effects of circadian rhythm and dietary protein intake on gentamicin pharmacokinetics. 1986

C J Dickson, and M S Schwartzman, and J S Bertino

The effects of dietary protein loading and circadian cycle on the pharmacokinetics of gentamicin were studied in healthy adult men. Ten subjects fasted overnight, and at 8 AM the next morning they received gentamicin, 1.5 mg/kg. Serum and urine samples were obtained over a 6-hour period. In two additional clearance studies with 2-week washout periods in between, 10 subjects were given the same dose of gentamicin at 8 PM in the fasted state and six subjects were also studied in a protein-supplemented (90 gm) state. Pharmacokinetic analysis revealed no significant effect of circadian cycle on gentamicin pharmacokinetic parameters at each of the two fasted periods. In contrast, dietary protein loading resulted in a significant decrease in the elimination t1/2 (P less than 0.05) and an increase in total body clearance compared with the fasted 8 PM study. Urinary excretion of gentamicin was also found to increase significantly (P = 0.03) as a result of protein intake compared with the fasted evening study period. Our study demonstrates the importance of dietary controls in chronopharmacokinetic studies of drugs eliminated predominantly by renal mechanisms.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D002940	Circadian Rhythm	The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs or environmental and physiological stimuli.	Diurnal Rhythm,Nyctohemeral Rhythm,Twenty-Four Hour Rhythm,Nycthemeral Rhythm,Circadian Rhythms,Diurnal Rhythms,Nycthemeral Rhythms,Nyctohemeral Rhythms,Rhythm, Circadian,Rhythm, Diurnal,Rhythm, Nycthemeral,Rhythm, Nyctohemeral,Rhythm, Twenty-Four Hour,Rhythms, Circadian,Rhythms, Diurnal,Rhythms, Nycthemeral,Rhythms, Nyctohemeral,Rhythms, Twenty-Four Hour,Twenty Four Hour Rhythm,Twenty-Four Hour Rhythms
D003404	Creatinine		Creatinine Sulfate Salt,Krebiozen,Salt, Creatinine Sulfate,Sulfate Salt, Creatinine
D004044	Dietary Proteins	Proteins obtained from foods. They are the main source of the ESSENTIAL AMINO ACIDS.	Proteins, Dietary,Dietary Protein,Protein, Dietary
D005215	Fasting	Abstaining from FOOD.	Hunger Strike,Hunger Strikes,Strike, Hunger,Strikes, Hunger
D005839	Gentamicins	A complex of closely related aminoglycosides obtained from MICROMONOSPORA purpurea and related species. They are broad-spectrum antibiotics, but may cause ear and kidney damage. They act to inhibit PROTEIN BIOSYNTHESIS.	Gentamicin Sulfate (USP),Gentamycin,G-Myticin,Garamycin,Gentacycol,Gentamicin,Gentamicin Sulfate,Gentamycins,Gentavet,Genticin,G Myticin,GMyticin,Sulfate, Gentamicin
D005919	Glomerular Filtration Rate	The volume of water filtered out of plasma through glomerular capillary walls into Bowman's capsules per unit of time. It is considered to be equivalent to INULIN clearance.	Filtration Rate, Glomerular,Filtration Rates, Glomerular,Glomerular Filtration Rates,Rate, Glomerular Filtration,Rates, Glomerular Filtration
D006207	Half-Life	The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity.	Halflife,Half Life,Half-Lifes,Halflifes