BackgroundThe total effect of a medication is the sum of its drug effect, placebo effect (meaning response), and their possible interaction. Current interpretation of clinical trials' results assumes no interaction. Demonstrating such an interaction has been difficult due to lack of an appropriate study design.Methods180 adults were randomized to caffeine (300 mg) or placebo groups. Each group received the assigned intervention described by the investigators as caffeine or placebo, in a randomized crossover design. 4-hour-area-under-the-curve of energy, sleepiness, nausea (on 100 mm visual analog scales), and systolic blood pressure levels as well as caffeine pharmacokinetics (in 22 volunteers nested in the caffeine group) were determined. Caffeine drug, placebo, placebo-plus-interaction, and total effects were estimated by comparing outcomes after, receiving caffeine described as placebo to receiving placebo described as placebo, receiving placebo described as caffeine or placebo, receiving caffeine described as caffeine or placebo, and receiving caffeine described as caffeine to receiving placebo described as placebo, respectively.ResultsThe placebo effect on area-under-the-curve of energy (mean difference) and sleepiness (geometric mean ratio) was larger than placebo-plus-interaction effect (16.6 [95% CI, 4.1 to 29.0] vs. 8.4 [-4.2 to 21.0] mm*hr and 0.58 [0.39 to 0.86] vs. 0.69 [0.49 to 0.97], respectively), similar in size to drug effect (20.8 [3.8 to 37.8] mm*hr and 0.49 [0.30 to 0.91], respectively), and its combination with the later was larger than total caffeine effect (29.5 [11.9 to 47.1] mm*hr and 0.37 [0.22 to 0.64]). Placebo-plus-interaction effect increased caffeine terminal half-life by 0.40 [0.12 to 0.68] hr (P = 0.007).ConclusionsDrug and placebo effects of a medication may be less than additive, which influences the interpretation of clinical trials. The placebo effect may increase active drug terminal half-life, a novel mechanism of placebo action.Trial RegistrationClinicalTrials.gov identification number - NCT00426010.

BackgroundAlthough informed consent is an integral part of clinical practice, its current doctrine remains mostly a matter of law and mainstream ethics rather than empirical research. There are scarce empirical data on patients’ perceived purpose of informed consent, which may include administrative routine/courtesy gesture, simple honest permission, informed permission, patient-clinician shared decision-making, and enabling patient’s self decision-making. Different purposes require different processes.MethodsWe surveyed 488 adults who were planning to undergo or had recently undergone written informed consent-requiring procedures. Perceptions of informed consent purpose (from norm and current practice perspectives) were explored by asking respondents to rank (1 = most reflective) 10 randomly-presented statements: “meaningless routine”, “courtesy gesture” “litigation protection”, “take away compensation rights”, “inform patient’, “make sure patient understand”, “document patient’s decision”, “discover patient’s preferences”, “have shared decision”, and “help patient decide”.ResultsRespondents’ mean (SD) age was 38.3 (12.5); 50.4% were males, 56.8% had ≥ college education, and 37.3% had undergone a procedure. From the norm perspective, the least reflective statement was “meaningless routine” (ranked 1–3 by 2.6% of respondents) and the most reflective statements were “help patient decide”, “make sure patient understand”, and “inform patient” (ranked 1–3 by 65%, 60%, and 48% of respondents with median [25%,75%] ranking scores of 2 [1,5], 3 [2,4], and 4 [2,5], respectively). Compared to their counterparts, males and pre-procedure respondents ranked “help patient decide” better, whereas females and post-procedure respondents ranked “inform patient” better (p = 0.007 to p < 0.001). Age was associated with better ranking of “help patient decide” and “make sure patient understand” statements (p < 0.001 and p = 0.002, respectively), which were ranked 1–3 by only 46% and 42% of respondents from the current practice perspective (median ranking score 4 [2,6], p < 0.001 vs. norm perspective for both).Conclusions1) the informed consent process is important to patients, however, patients vary in their views of its purpose with the dominant view being enabling patients’ self decision-making, 2) males, pre-procedure, and older patients more favor a self decision-making purpose, whereas females and post-procedure patients more favor an information disclosure purpose, and 3) more self decision-making and more effective information disclosure than is currently practiced are desired. An informed consent process consistent with Mill’s individual autonomy model may be suitable for most patients.

BackgroundPosthumous organ procurement is hindered by the consenting process. Several consenting systems have been proposed. There is limited information on public relative attitudes towards various consenting systems, especially in Middle Eastern/Islamic countries.MethodsWe surveyed 698 Saudi Adults attending outpatient clinics at a tertiary care hospital. Preference and perception of norm regarding consenting options for posthumous organ donation were explored. Participants ranked (1, most agreeable) the following, randomly-presented, options from 1 to 11: no-organ-donation, presumed consent, informed consent by donor-only, informed consent by donor-or-surrogate, and mandatory choice; the last three options ± medical or financial incentive.ResultsMean(SD) age was 32(9) year, 27% were males, 50% were patients’ companions, 60% had ≥ college education, and 20% and 32%, respectively, knew an organ donor or recipient. Mandated choice was among the top three choices for preference of 54% of respondents, with an overall median[25%,75%] ranking score of 3[2,6], and was preferred over donor-or-surrogate informed consent (4[2,7], p < 0.001), donor-only informed consent (5[3,7], p < 0.001), and presumed consent (7[3,10], p < 0.001). The addition of a financial or medical incentive, respectively, reduced ranking of mandated choice to 7[4,9], p < 0.001, and 5[3,8], p < 0.001; for donor-or-surrogate informed consent to 7[5,9], p < 0.001, and 5[3,7], p = 0.004; and for donor-only informed consent to 8[6,10], p < 0.001, and 5[3,7], p = 0.56. Distribution of ranking score of perception of norm and preference were similar except for no-organ donation (11[7,11] vs. 11[6,11], respectively, p = 0.002). Compared to females, males more perceived donor-or-surrogate informed consent as the norm (3[1,6] vs. 5[3,7], p < 0.001), more preferred mandated choice with financial incentive option (6[3,8] vs. 8[4,9], p < 0.001), and less preferred mandated choice with medical incentive option (7[4,9] vs. 5[2,7], p < 0.001). There was no association between consenting options ranking scores and age, health status, education level, or knowing an organ donor or recipient.ConclusionsWe conclude that: 1) most respondents were in favor of posthumous organ donation, 2) mandated choice system was the most preferred and presumed consent system was the least preferred, 3) there was no difference between preference and perception of norm in consenting systems ranking, and 4) financial (especially in females) and medical (especially in males) incentives reduced preference.

A randomized crossover study was conducted on 26 healthy Arab males to compare the bioavailability of two formulations of fluconazole 150 mg capsules, Fluconazole (test) and Diflucan (reference). The formulations were administered after an overnight fast with a washout period of 2 weeks. Twenty blood samples (per period) were collected over 168 h, plasma fluconazole concentrations were determined by locally validated high performance liquid chromatography (HPLC) assay and pharmacokinetic parameters were analysed by the standard non-compartmental method. The mean +/- SD maximum concentration (C(max)), time to reach maximum concentration (T(max)), area under the curve (AUC(0-->t) and AUC(0-->infinity)) and elimination half-life (t(1/2)) were 3.17+/-0.47 and 3.24+/-0.59 microg/ml, 2.62+/-2.01 and 2.65+/-1.63 h, 149.52+/-29.49 and 151.36+/-25.84 microg.h/ml, 163.57+/-29.9 and 164.89+/-26.46 microg.h/ml, and 36.81+/-5.72 and 36.56+/-5.36 h for the test and reference drug, respectively. These values are similar to previously reported values in other ethnic groups. The parametric 90% confidence intervals on the mean of the difference (test-reference) between the log-transformed values of the two formulations were 95.484% to 101.035%, 96.382% to 101.245% and 94.621% to 102.074% for AUC(0-->t), AUC(0-->infinity) and C(max), respectively. The results indicate that the two formulations are equivalent in the rate and extent of absorption. Further, a review of the literature indicates that there is no apparent ethnic variation in the absorption and elimination rates of fluconazole.

A randomized single-dose cross-over study was conducted on 24 healthy male volunteers to compare the bioavailability of two metformin (CAS 657-24-9) tablet formulations, Emiphage (test) and a commercially available original preparation (reference). A dose of 850 mg was administered after an overnight fast with a washout period of seven days. Eighteen blood samples were collected over 32 h. Metformin concentrations in deproteinized serum were determined by a locally validated High Performance Liquid Chromatographic (HPLC) assay, and pharmacokinetic parameters were analyzed by the standard non-compartmental method. Mean +/- SD maximum concentration (C(max)), time to reach maximum concentration (T(max)), area under the curve (AUC(0 --> t) and AUC(0 --> infinity)), and elimination half-life (t(1/2)) were 1.73 +/- 0.54 and 1.86 +/- 0.67 microg/ml, 2.6 +/- 1.2 and 2.0 +/- 1.0 h, 10.72 +/- 3.93 and 10.82 +/- 3.72 microg x h/ml, 11.53 - 4.14 and 11.6 +/- 3.84 microg x h/ml, and 3.1 +/- 0.7 and 3.1 +/- 0.9 h for the test and reference formulation, respectively. The parametric 90% confidence intervals on the mean of the difference (test - reference) between log-transformed values of the two formulations were 82.92% to 98.78%, 85.95% to 101.47%, and 77.82% to 100.4% for AUC(0 --> t), AUC(0 --> infinity), and C(max), respectively. The results indicate that the two formulations can be considered equivalent in the extent of absorption under fasting conditions.