Pharmacokinetics food affecting

Some mechanisms by which foods affect the pharmacokinetics of drugs are ... 

Amphetamine mixture - Peak plasma concentrations occur in about 3 hours (Adderall) and 7 hours (Adderall XR). Elimination half-life is 10 to 13 hours in adults and 9 to 11 hours in children. Extended-release amphetamine mixture capsules demonstrate linear pharmacokinetics. There is no unexpected accumulation at steady state. Food does not affect the extent of absorption of extended-release amphetamine mixture capsules, but prolongs T ax by 2.5 hours. 

Drug/Food interactions Food does not affect the pharmacokinetics of entacapone. 

The pharmacokinetic characteristics of dofetilide are summarized below. Although the absorption of dofetilide is delayed by ingestion of food, the total bioavailability is not affected. Dosing requires adjustment in patients with renal insufficiency. 

The standard pharmacokinetic parameters of the compound such as a half-life or bioavailability cannot be reliably calculated, because the concentrations in plasma are below lOpg/mL. As analogously expected from the results on the shift in keto-alcohol equilibrium of 16,16-difluoro-PGE2, it is rapidly metabolized by C-15 reduction mediated by the ubiquitously expressed carbonyl reductase. The metabolism followed by jS-oxidation and co-oxidation forms a mixture of a and fi epimers at the 15-hydroxy moiety as a sole measurable metabolite [46], In 2006, the US Food and Drug Administration approved the drug application for an oral treatment of chronic idiopathic constipation in adults, estimating that 4-5 million Americans are affected. Lubiprostone has also completed a phase II trial in constipation-predominant irritable bowel syndrome, and has been further evaluated for other bowel dysfunctions. 

Pharmacokinetics Well absorbed from the G1 tract (not affected by food). Protein binding less than 5%. Widely distributed. Crosses the blood-brain barrier. Primarily excreted unchanged in urine. Removed by hemodialysis. Half-life 5-7 hr (increased in impaired renal function and the elderly). 

Pharmacokinetics Rapidly and extensively absorbed after PO administration (food decreases drug plasma concentration but doesn t affect absorption). Protein binding 97%, Completely hydrolyzed to active metabolite mycophenolic acid. Primarily excreted in urine. Not removed by hemodialysis. Half-life 17,9 hr. 

Lincomycin is readily absorbed when given orally but its resorption may be affected by the presence of food. It is also completely absorbed from intramuscular sites. It is widely distributed in the body and does not appear to concentrate in any particular tissue. Pharmacokinetic smdies indicate that bile is an important route of excretion. Lincomycin has been also shown to be excreted in the milk of lactating cows and goats (111). Metabolism of lincomycin in food-producing animals proceeds primarily through oxidation of the sulfur atom to the sulfoxide metabolite, demethylation to the N-desmethyl metabolite, and conversion of both metabolites to N-desmethyl lincomycin sulfoxide. 

Renal clearance averages 388 ml/minute and is largely uninfluenced by dose. The AUC is dose-dependent and is not affected by food. The pharmacokinetics are not affected by obesity (3). 

Modeling of food effect on apomine s pharmacokinetics. It was expected that food would affect relative bioavailability (F1). Hence, three models had been tested ... 

The pharmacokinetics of modafinil are not affected, to a clinically significant extent, by volunteer age or food intake, but both the maximum plasma concentration and the elimination half-life of the drug are increased in patients with hepatic or renal impairment. It was found that peak plasma concentrations of modafinil were reached 2.3 h after a single 200 mg oral dose in healthy volunteers. Over the dose range 200 to 600 mg, the pharmacokinetics of modafinil were linear and dose dependent. Orally administered modafinil is extensively biotransformed in the liver to the inactive metabolites modafinil acid 6 (major metabolite) and modafinil sulphone 7 (minor metabolite), before being eliminated primarily in the... 

Pharmacokinetics The drug is well absorbed after oral administration. If taken with food, peak levels may be lower but total drug absorbed is not affected. Penetration across the blood-brain barrier is excellent, and the drug has a half-life of 1 hour. Most of the AZT is glucuronidated by the liver and then excreted in the urine. 

It is known that foods have the potential to affect in particular the pharmacokinetics... 

As might be expected, the presence of food in the gastrointestinal tract has been shown to affect lithium absorption and a diurnal variation in renal lithium clearance has been reported 183, 184). In our experiments, diurnal and other factors appeared to influence lithium pharmacokinetics to a greater degree than did formulation differences 182). We conclude that the practice of administering an early evening dose after a meal may delay the lithium peak sufficiently to reduce the possible discomfort of any transient side effects and may improve patient compliance. This is more important than the choice of preparation to be given. 

Enalapril maleate (Vasotec) Route PO/IV Pregnancy category D Pharmacokinetic Readily absorbed from GI tract (not affected by food). PB 50%-60% excreted in urine. 

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