Time to Peak Level

A study in 3 healthy subjects and 3 patients, and a later study in 7 healthy subjects, found that colestyramine 4 g delayed the absorption of a single 500-mg dose of aspirin (time to peak levels extended from 30 to 60 minutes) but the total amount absorbed was only reduced by 5 to 6%. Some of the subjects had slightly higher serum aspirin levels while taking colestyramine. Similar results were reported in another study (a 31% lower plasma aspirin level at 60 minutes, but no difference in total absorption). There would seem to be little reason for avoiding concurrent use unless rapid analgesia is needed. 

A study in healthy subjects given cefradine 500 mg in the fasting state or immediately after a meal found the time to peak levels was increased from... 

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. 

A report briefly states that no changes in blood tolbutamide or in fasting blood glucose levels were seen in diabetics given diflunisal 375 mg twice daily. In a study in 12 type 2 diabetic patients, sulindac 400 mg daily did not affect the half-life, plasma levels, time-to-peak levels or AUC of tolbutamide. An unimportant reduction in fasting blood glucose levels was... 

A study in 12 healthy subjects found that a single 40-mg dose of methoxsalen significantly increased the AUC and peak plasma level of a single 200-mg dose of ciclosporin by about 14% and 8%, respectively. In two patients the AUCs increased by 1.8-fold and 2.7-fold, respectively. The half-life and time to peak levels were not affected. As methoxsalen absorption is subject to high interindividual variation, this particular study was unable to detect a significant difference in methoxsalen pharmacokinetics although the AUC and peak levels tended to be reduced by concurrent ciclosporin. ... 

Because of the time it takes to reach the blood stream, the effects of THC are quicker and greater when it is smoked (e.g., in marijuana cigarettes) than when it is taken orally, with time-to-peak levels in the brain being 7-8 minutes vs. an hour, respectively. The psychoactive effects peak within 10-30 minutes and disappear after an hour or two, though traces of THC... 

The proteetion level of an arrester, is a function of the magnitude of arrester discharge current (/ ), and the time to peak of the surge (/ ). and is influenced by the following. 

Photo flash Compositions. Workers at PicArsn have investigated a series of mixts of K perchlorate with powd metals for use as photoflash compns. Info on candlepower, time to peak luminosity, and duration of flash, as well as performance at sea level and 1 x 10s feet, are given for each compn (Ref 23). A standard mil photo flash compn is given as 40% atomized Al, 30% Ba nitrate, and 30% K perchlorate (Ref 22, P 274)... 

Sub-type inhibition of the 5a-reductase enzyme Percent of inhibition of serum dihydrotestosterone level Percent of patients with reduction in serum dihyrotestosterone Time to peak onset of reduction in serum dihydrotestosterone level Percent inhibition of intraprostatic d i hy d rotestosterone Half-life... 

Pharmacodynamics Duration 1-4 weeks Absorption IM slow Time to peak serum levels 12-24 hours Duration 15-24 hours Absorption IM slow Distribution Poor blood-brain barrier penetration, enters breast milk Metabolism =30% hepatic inactivation Protein binding 65% Time to peak serum levels 1-4 hours Excretion Urine (60-90% as unchanged drug) Clearance Renal... 

The answer is e. (Hardman, p 21J The fraction of a drug dose absorbed after oral administration is affected by a wide variety of factors that can strongly influence the peak blood levels and the time to peak blood concentration. The Vd and the total body clearance (Vd x first-order fte) also are important in determining the amount of drug that reaches the target tissue. Only the area under the blood concentration-time curve, however, reflects absorption, distribution, metabolism, and excretion factors it is the most reliable and popular method of evaluating bioavailability... 

Time to Peak Plasma Level Generic Name (hours)... 

Absorption - ZWeuton is rapidly absorbed upon oral administration with a mean time to peak plasma concentration (T ax) I hours and a mean peak level (Cmax) of 4.98 mcg/mL. Plasma concentrations of zileuton are proportional to... 

Drug Usual adult oral dose (mg) Time to peak plasma levels (h) Half-life (h) Protein binding (%) Urinary excretion, unchanged (%)... 

Absorption/Distribution - In a single 4 g pharmacokinetic study with food in normal volunteers, the initial time to a 2 mcg/mL serum level of aminosalicylic acid was 2 hours the median time to peak was 6 hours the mean peak level was 20 mcg/mL a level of 2 mcg/mL was maintained for an average of 7.9... 

Drug Time to Peak Plasma Level (testing) (hr) Plasma Half-Life (hr) Protein Binding (%) Urinary Excretion (%) Notes... 

A composition based on diketopiperazine derivatives (3,6-bis (N-fumaryl-N-(n-butyl) amino-2, 5-diketopiperazine) has been investigated as a pulmonary drug delivery system, termed Technospheres (Pharmaceutical Discovery Corp., Elmsford, NY) (Pohl et al. 2000 Steiner et al. 2002). The diketopiperazine derivatives self-assemble into microparticles at low pH with a mean diameter of approximately 2 pm. During self-assembly, diketopiperazine derivatives microencapsulate peptides present in the solution. Insulin incorporated in diketopiperazine derivatives (TI) was administered to five healthy humans by the use of a capsule-based inhaler with a passive powder deagglomeration mechanism. Relative and absolute bioavailability of TI in the first 3 hours (0-180 min) were 26 12% and 15 5%, and for 6 hours (0-360 min) 16 8% and 16 6%, respectively (Steiner et al. 2002). The time to peak action for glucose infusion rates was shorter with both IV (14 6 min) injection and inhalation (39 36 min), as compared to SC administration (163 25 min). This rapid absorption of insulin would be beneficial for diabetic patients who need to rapidly affect their glucose levels. 

Gonadorelin has been used to test pituitary luteinizing hormone (LH) responsiveness. Administered as a 100 eg test dose, the average times to peak LH levels are 34 minutes (men) or 72 minutes (women) following subcutaneous gonadorelin and 27 minutes (men) or 36 minutes (women) following intravenous gonadorelin. There is considerable individual variation in response. 

Laube, B.L. Benedict, G.W. Dobs, A.S. Time to peak 54. insulin level, relative bioavailability, and effect of site of deposition of nebulized insulin in patients with noninsulin-dependent diabetes mellitus. J. Aerosol Med. 1998, 11,... 

The time to peak serum levels of solanaceous alkaloids is variable and depends on the species and amount ingested. Reports suggest peak levels are attained in 4-8 h. Solanine is converted to solanidine by hydrolysis. Solanine is rapidly excreted in urine and feces. The elimination half-life of solanidine is reported to be 11 h. 

The peak level is the highest plasma concentration of the medication at a specific time. A peak level indicates the rate that a medication is absorbed by the body, which is influenced by the route the medication is administered to the patient. 

Drug in plasma verses time post application is plotted and pharmacokinetic parameters of AUCg 24h ( rea under curve), max (peak plasma level), t (time to peak plasma level) and... 

Insulin by Aerosol. Early studies showed that aerosolized insulin had a bioavailability of 57% after delivery via endotracheal tube into animals, about 10-fold higher than after instillation [125]. Human studies documented average time to peak insulin level at 40 min after aerosol inhalation by human diabetics and normalization of blood glucose [126]. Continuing research focuses on delivery systems [127-129] and particle modification [130,131] to enhance efficacy. Success of these new approaches will depend heavily upon their cost and convenience for patients. At this point, systems seem to depend upon nebulization, a distinct disadvantage for active people. Unless patients quickly recognize aerosolized insulin as distinctly superior to current therapy, e.g., subcutaneous insulin, the method will not gain acceptance. 

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