Early pharmacokinetics of low dosage mycophenolate exposure in Thai kidney transplant recipients

Background The effects of mycophenolic acid exposure in the early period after transplantation on clinical outcomes have been reported; however, mycophenolic acid exposure in the early period after transplantation in Asian kidney transplant recipients who receive 1.5 g/d mycophenolate mofetil has never been investigated. Objective To determine mycophenolic acid exposure on day 3 post-transplantation in kidney transplant recipiens who receive 1.5 g/d mycophenolate mofetil. The effects of the reduced renal function on mycophenolic acid area under the concentration–time curve (AUC) and the achievement of the target AUC on the incidence of biopsy proven acute rejection during the first month post-transplantation were also evaluated. Setting A university hospital Method Blood samples and 24-h urine were collected on day 3 post-transplantation. Main outcome measures The mycophenolic acid AUC was calculated by linear trapezoidal rule and compared with the target of 45 mg*h/L. Results Of 42 Thai kidney transplant recipiens, the mean mycophenolic acid AUC of 45.1 mg*h/L (SD 14.7) was comparable to the AUC target (P?=?0.962). Significant differences of the mycophenolic acid AUC were observed between patients with urine output of?<?2400 mL and those with urine output?≥?2400 mL (35.3?±?6.6 and 47.4?±?15.2, respectively; P?=?0.002), and between patients with 24-h measured CrCl?<?25 mL/min and those with CrCl?≥?25 mL/min (38.0 (29.0, 42.2) and 49.2?±?14.0, respectively; P?=?0.017). Proportions of overall biopsy proven acute rejection among patients with mycophenolic acid AUC of?<?45 and?≥?45 mg*h/L were comparable (20.0% and 23.5%, respectively; P?=?1.000). Conclusions After the starting dosage of 1.5 g/d mycophenolate mofetil, the mean mycophenolic acid AUC on day 3 post-kidney transplantation is comparable with the target of 45 mg*h/L. Severely reduced renal function significantly influences mycophenolic acid exposure.

     

Diltiazem augments the influence of MDR1 genotype status on cyclosporine concentration in Chinese patients with renal transplantation

Aim:

Co-administration of diltiazem can reduce the dosage of cyclosporine (CsA) in patients with renal transplantation. In this study, we investigated how diltiazem altered the relationship between MDR1 genetic polymorphisms and CsA concentration in Chinese patients with renal transplantation.

Methods:

A total of 126 renal transplant patients were enrolled. All the patients received CsA (2–4 mg·kg⁻¹·d⁻¹), and diltiazem (90 mg/d) was co-administered to 76 patients. MDR1-C1236T, G2677T/A, and C3435T polymorphisms were genotyped. The whole blood concentration was measured using the FPIA method, and the adjusted trough concentrations were compared among the groups with different genotypes.

Results:

In all patients, MDR1-C1236T did not influence the adjusted CsA trough concentration. With regard to MDR1-3435, the adjusted CsA trough concentration was significantly higher in TT carriers than in CC and CT carriers when diltiazam was co-administered (58.83±13.95 versus 46.14±7.55 and 45.18±12.35 ng/mL per mg/kg, P=0.011), and the differences were not observed in patients without diltiazam co-administered. With regard to MDR1-2677, the adjusted CsA trough concentration was significantly higher in TT carriers than in GG and GT carriers when diltiazam was co-administered (61.31±12.93 versus 52.25±7.83 and 39.70±7.26 ng/mL per mg/kg, P=0.0001). The differences were also observed in patients without diltiazam co-administered (43.27±5.95 versus 35.22±7.55 and 29.54±5.35 ng/mL per mg/kg, P=0.001). The adjusted CsA trough blood concentration was significantly higher in haplotype T-T-T and haplotype T-T-C carriers than in non-carriers, regardless of diltiazem co-administered.

Conclusion:

MDR1 variants influence the adjusted CsA trough concentration in Chinese patients with renal transplant, and the influence more prominent when diltiazem is co-administered.     

Decreased vancomycin clearance in patients with congestive heart failure

Purpose

Congestive heart failure (CHF) alters the pharmacokinetics of various drugs, including cardiovascular agents, due to decreased cardiac output and decreased renal blood flow. The purpose of this study was to evaluate the influence of CHF on the clearance of vancomycin, a glycopeptide antibacterial agent.

Methods

After reviewing more than 1,500 clinical charts of patients who received vancomycin therapy and whose serum vancomycin level was monitored, we identified 101 patients who also had the left ventricular ejection fraction (LVEF) assessed at that time. The fluorescence polarization immunoassay method was used to measure vancomycin serum concentrations in these patients 1 h after the end of vancomycin infusion and just before the next administration. Using these two measurements, we calculated the pharmacokinetic parameters using the Bayesian estimator.

Results

Patients with an LVEF of?<40 % (16 patients) or those with an LVEF of ≥ 40 %? and <60 % (40 %?≤?LVEF?<?60 % ; 32 patients) had a significantly lower vancomycin clearance than patients with LVEF of?≥60 % (53 patients) (2.29?±?0.95 or 2.79?±?0.99 vs. 3.50?±?1.04 L/h; p?<?0.001 or p?<?0.01, respectively). Vancomycin clearance was strongly correlated not only with estimated creatinine clearance (CLcr) in patients with an LVEF of?<40 % (r?=?0.828) and 40 %?≤?LVEF?<?60 % (r?=?0.773), but also with an LVEF in patients with a CLcr of?<60 mL/min (r?=?0.646). Consistent with these findings, multiple regression analysis revealed that CLcr, LVEF and body weight were important independent variables for vancomycin clearance (r ²?=?0.649).

Conclusions

Vancomycin clearance decreased with decreasing cardiac function (LVEF) and decreasing CLcr. This finding suggests that vancomycin clearance is affected by cardiac function and would be predicted not only CLcr but also by LVEF.     

Celecoxib as adjunctive treatment to risperidone in children with autistic disorder: a randomized, double-blind, placebo-controlled trial

Rational

Autism is associated with activation of the inflammatory response system.

Objective

This study aims to assess the efficacy of a cyclooxygenase-2 inhibitor, celecoxib, as adjunctive therapy in the treatment of autism

Methods

In a 10-week randomized double-blind placebo-controlled study, 40 outpatient children with a Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision clinical diagnosis of autism were randomly allocated to celecoxib plus risperidone or placebo plus risperidone. The dose of risperidone and celecoxib were titrated up to 3 and 300 mg/day, respectively. Patients were assessed at baseline and after 2, 4, 6, and 10 weeks of starting medication using the Aberrant Behavior Checklist-Community (ABC-C) Rating Scale. Primary outcome measure was the change in irritability subscale of ABC-C.

Results

Significant time?×?treatment interaction was observed for Irritability (F (1.658, 63.021)?=?13.580, P?<?0.001), Lethargy/Social Withdrawal (F (1.948, 74.032)?=?16.811, P?<?0.001), and Stereotypic Behavior (F(1.742, 66.198)?=?12.104, P?<?0.001), but not for Hyperactivity/Noncompliance (F (2.564, 97.424)?=?1.469, P?=?0.232), and Inappropriate Speech subscales (F (1.607, 61.075)?=?0.173, P?=?0.794). By week 10, patients in the celecoxib group showed significantly greater improvement in the Irritability (P?<?0.001), Lethargy/Social Withdrawal (P?<?0.001), and Stereotypic Behavior (P?<?0.00) but not in Hyperactivity/Noncompliance (P?=?0.202) and Inappropriate Speech (P?=?0.802) subscales than the placebo group. Complete response was achieved by four (20 %) patients in the placebo group and 11 (55 %) patients in the celecoxib group (χ ² (1)?=?5.227, P?=?0.022). Frequency of side effects was similar between the two groups.

Conclusions

Combination of risperidone and celecoxib was superior to risperidone alone in treating irritability, social withdrawal, and stereotypy of children with autism. (Registration, www.irct.ir; IRCT138711091556N2)     

Effects of itraconazole on the pharmacokinetics and pharmacodynamics of intravenously and orally administered oxycodone

Background

The aim of this study was to investigate the effects of the cytochrome P450 3A4 (CYP34A) inhibitor itraconazole on the pharmacokinetics and pharmacodynamics of orally and intravenously administered oxycodone.

Methods

Twelve healthy subjects were administered 200 mg itraconazole or placebo orally for 5 days in a four-session paired cross-over study. On day 4, oxycodone was administered intravenously (0.1 mg/kg) in the first part of the study and orally (10 mg) in the second part. Plasma concentrations of oxycodone and its oxidative metabolites were measured for 48 h, and pharmacodynamic effects were evaluated.

Results

Itraconazole decreased plasma clearance (Cl) and increased the area under the plasma concentration–time curve (AUC0–∞) of intravenous oxycodone by 32 and 51%, respectively (P?<?0.001) and increased the AUC(0–∞) of orally administrated oxycodone by 144% (P?<?0.001). Most of the pharmacokinetic changes in oral oxycodone were seen in the elimination phase, with modest effects by itraconazole on its peak concentration, which was increased by 45% (P?=?0.009). The AUC(0–48) of noroxycodone was decreased by 49% (P?<?0.001) and that of oxymorphone was increased by 359% (P?<?0.001) after the administration of oral oxycodone. The pharmacologic effects of oxycodone were enhanced by itraconazole only modestly.

Conclusions

Itraconazole increased the exposure to oxycodone by inhibiting its CYP3A4-mediated N-demethylation. The clinical use of itraconazole in patients receiving multiple doses of oxycodone for pain relief may increase the risk of opioid-associated adverse effects.     

Evaluation of ameliorative effect of quercetin in experimental model of alcoholic neuropathy in rats

Objective

The objective of the present investigation was to study the neuroprotective effect of the quercetin in alcohol induced neuropathy in rats.

Materials and methods

Male Wistar rats were administered alcohol (10?gm/kg, 35% v/v, p.o. b.i.d.) for 10?weeks. Alpha tocopherol (vitamin E) was used as a standard drug. Vitamin E (100?mg/kg) and quercetin (10, 20 and 40?mg/kg) were co-administered 1?h after ethanol administration for 10?weeks. Behavioral assessment parameters, such as motor incoordination, tactile allodynia, mechanical and thermal hyperalgesia were recorded in all groups of animals. Meanwhile, motor nerve conduction velocity was also recorded. Biochemical parameters, such as nitric oxide (NO), Na⁺?CK⁺-ATPase, malondialdehyde (MDA) and myeloperoxidase (MPO) were estimated in sciatic nerve. Apoptosis index was determined with help of DNA fragmentation in sciatic nerve.

Results and discussion

Chronic ethanol administration for 10?weeks resulted in significant (P?<?0.001) development of neuropathic pain. Chronic treatment with quercetin (20 and 40?mg/kg) for 10?weeks significantly (P?<?0.001) attenuated allodynia, hyperalgesia as well as motor coordination and impaired nerve conduction velocity along with decreased level of membrane-bound Na⁺?CK⁺-ATPase. It also significantly (P?<?0.001) decreased elevated levels of MDA, MPO as well as pro-inflammatory mediators, such as NO. It also decreased the extent of DNA fragmentation. This alteration was more significant in vitamin E treated rats (100?mg/kg). Quercetin is a proven antioxidant that might have decreased the oxidative stress produced by chronic alcoholism.

Conclusion

The present investigation elucidates neuroprotective effect of quercetin in alcohol induced neuropathy through modulation of membrane-bound inorganic phosphate enzyme and inhibition of release of oxido-inflammatory mediators, such as MDA, MPO and NO.     

Sex difference in QTc prolongation in chronic institutionalized patients with schizophrenia on long-term treatment with typical and atypical antipsychotics

Objective

The rate-corrected electrocardiographic QT (QTc) interval may significantly increase in patients with schizophrenia taking antipsychotics. The objective of this naturalistic study was to assess the prevalence of prolonged QTc interval in a large population of inpatients with chronic schizophrenia and to explore QTc relationship with demographic variables and prescribed treatments.

Materials and methods

Electrocardiograms were obtained from age- and sex-matched 456 controls and 1,006 inpatients with schizophrenia (male/female?=?689/317) taking antipsychotics. QTc prolongation was defined as a mean value of two standard deviations above the controls. The adjusted relative risk was calculated using logistic regression analysis.

Results

QTc prolongation was present in 45 (4.5%) of 1,006 patients overall. Fewer men (3.2%, 22 of 689) than women (7.3%, 23 of 317) displayed QTc prolongation (p?<?0.004). Moreover, QTc intervals were shorter in male (391?±?31?ms) than female subjects (400?±?37?ms) (p?<?0.001). Clozapine was found to produce a longer QTc intervals compared to risperidone and typical antipsychotics. Furthermore, multiple regression analysis showed that significant predictors for QTc prolongation were comorbid cardiovascular disease, antipsychotic types, sex, and age (all p?<?0.01).

Conclusion

Our present findings suggest that there are sex differences in the prevalence of QTc prolongation and QTc lengthening in schizophrenia. Antipsychotic types are risk factors for QTc prolongation, and risks are substantially higher for clozapine.     

Prospective randomized double-blind trial of racecadotril compared with loperamide in elderly people with gastroenteritis living in nursing homes

Aim

Our aim was to compare the efficacy and tolerability of loperamide and racecadotril in elderly patients with acute diarrhea.

Research design and methods

We performed a randomized, prospective, double-blind, and parallel group design implemented in geriatric nursing homes in Catanzaro, Italy, from February 2008 to March 2009. Patients of both sexes were randomly allocated to receive either one tablet of racecadotril 100 mg every 8 h or two tablets of loperamide 2.0 mg followed by one tablet after each unformed stool, up to four tablets in any 24-h period. Patients were treated until recovery, defined as the production of two consecutive normal stools or no stool production for a period of 12 h.

Results

Normal stools were collected 36?±?4 h after the beginning of racecadotril and in 63?±?6 h from the beginning of loperamide administration (P?<?0.01). The median time of abdominal pain in the intent-to-treat (ITT) population was 14 h for racecadotril and 28 h for loperamide. In the per-protocol (PP) population, the median time of abdominal pain was 14 h for racecadotril and 32 h for loperamide (P?<?0.01). About the 50% of patients experienced at least one adverse event during the study: 12% in the racecadotril group and 60% in the loperamide group. The most frequently occurring adverse events were nausea and constipation. Genetic analysis did not report the presence of rapid or poor metabolizers. Pharmacoeconomic analysis performed at the end of our study documented an increase in costs in the loperamide group with respect to the racecadotril group (P?<?0.01).

Conclusions

Racecadotril is more effective than loperamide?probably due to drug interaction with loperamide?and it is not related to pharmacogenetic susceptibility. Racecadotril is also more cost effective than loperamide.     

Bevacizumab increases the risk of gastrointestinal perforation in cancer patients: a meta-analysis with a focus on different subgroups

Background

The aim of this meta-analysis was to gather current data and evaluate not only the risk of gastrointestinal (GI) perforation with bevacizumab, but also the potential risk factors for this adverse event.

Materials and methods

We carried out a literature search in PubMed for randomized controlled trials (RCTs) reported from January 2000 to December 2013. Summary incidence, relative risks (RRs) and 95 % confidence intervals (CIs) were calculated using random-effects or fixed-effects models based on the heterogeneity of the included studies.

Results

A total of 26,833 patients from 33 RCTs were included in the meta-analysis. Bevacizumab-containing therapy significantly increased the risk of developing all-grade (RR 3.35, 95 % CI 2.35–4.79, P?<?0.001) and fatal GI perforation (RR 3.08, 95%CI: 1.04–9.08, P?=?0.042). On subgroup analysis, no significant risk differences were found based on bevacizumab dosage, treatment duration, treatment line, type of clinical trial and median age. When stratified by tumor types, a significantly increased risk of GI perforation with bevacizumab was observed in colorectal cancer (RR 2.84, 95% CI 1.43–5.61, P?=?0.003), gynecologic cancer (RR 3.37, 95% CI 1.71–6.62, P?<?0.001) and prostate cancer (RR 6.01, 95% CI 1.78–20.28, P?=?0.004). Additionally, the use of bevacizumab significantly increased the risk of GI perforation when used in conjunction with taxanes (RR 3.09, 95% CI 1.92–4.96, P?<?0.001) or oxaliplatin (RR 2.85, 95% CI 1.07–7.57, P?=?0.036).

Conclusions

Bevacizumab treatment is associated with a significantly increased risk of developing GI perforation, and clinicians should be aware of the risks of GI perforation with the administration of this drug in cancer patients.     

Interaction between acetaminophen and warfarin in adults receiving long-term oral anticoagulants: a randomized controlled trial

Purpose

We investigated whether acetaminophen, given at 2?g/day and 3?g/day might potentiate the anticoagulant effect of warfarin.

Methods

Forty-five patients on stable warfarin therapy, enrolled in this prospective, randomized, parallel (three arms), placebo-controlled study, received a 10-day regimen of acetaminophen (2?g/day or 3?g/day) or placebo.

Results

The mean maximal INR increase was 0.70?±?0.49 and 0.67?±?0.62 in patients receiving acetaminophen at 2?g/day and 3?g/day, respectively (P?=?0.01 for the respective comparisons versus placebo). The INR increase became significant on day 3 and was independently and significantly predicted by a maximal decrease in factor II (R ²?=?0.36, P?R ²?=?0.46, P?R ²?=?0.563, P?Conclusion Acetaminophen, at 2?g/day or 3?g/day, enhanced the anticoagulant effect of warfarin in stable patients, thus requiring close INR monitoring in the clinical setting.     

A double-blind, placebo controlled, randomized trial of riluzole as an adjunct to risperidone for treatment of negative symptoms in patients with chronic schizophrenia

Rationale

Several recent studies have focused on glutamate modulating agents for symptoms relief in schizophrenia, especially negative symptoms which are resistant to conventional therapies.

Objectives

We aimed to assess the efficacy and tolerability of riluzole, an anti-glutamate agent with neuroprotective properties, as an adjunct to risperidone in improving negative symptoms of schizophrenia.

Methods

In this randomized double-blind placebo-controlled parallel-group study, 50 patients with chronic schizophrenia and a score of ≥20 on the negative subscale of positive and negative syndrome scale (PANSS) were enrolled in the active phase of their illness. Participants were equally randomized to receive riluzole (100 mg/day) or placebo in addition to risperidone (up to 6 mg/day) for 8 weeks. Participants were rated by PANSS every 2 weeks. The primary outcome of this study was the difference in the decrease of PANSS negative subscale score from baseline to the study endpoint between the two groups.

Results

By the study endpoint, riluzole-treated patients showed significantly greater improvement in the negative symptoms (P?<?0.001) as well as the PANSS total and general psychopathology subscale scores (P?=?0.001 and P?<?0.001; respectively) compared to the placebo group. Treatment group was the only significant predictor of changes in negative symptom in this trial (β?=??0.56, P?<?0.001). No significant difference was observed between two groups in the frequency of side effects.

Conclusion

These preliminary findings suggest that riluzole may be a safe and effective medication for the treatment of negative symptoms in patients with chronic schizophrenia. Further research and replication of study findings is warranted.

Clinical trial registry name and registration number

Iranian registry of clinical trials www.irct.ir, IRCT201107281556N26     

Patient- and physician-related risk factors for hyperkalaemia in potassium-increasing drug–drug interactions

Purpose

Hyperkalaemia due to potassium-increasing drug–drug interactions (DDIs) is a clinically important adverse drug event. The purpose of this study was to identify patient- and physician-related risk factors for the development of hyperkalaemia.

Methods

The risk for adult patients hospitalised in the University Hospital Zurich between 1 December 2009 and 31 December 2011 of developing hyperkalaemia was correlated with patient characteristics, number, type and duration of potassium-increasing DDIs and frequency of serum potassium monitoring.

Results

The 76,467 patients included in this study were prescribed 8,413 potentially severe potassium-increasing DDIs. Patient-related characteristics associated with the development of hyperkalaemia were pulmonary allograft [relative risk (RR) 5.1; p?<?0.0001), impaired renal function (RR 2.7; p?<?0.0001), diabetes mellitus (RR 1.6; p?=?0.002) and female gender (RR 1.5; p?=?0.007). Risk factors associated with medication were number of concurrently administered potassium-increasing drugs (RR 3.3 per additional drug; p?<?0.0001) and longer duration of the DDI (RR 4.9 for duration ≥6 days; p?<?0.0001). Physician-related factors associated with the development of hyperkalaemia were undetermined or elevated serum potassium level before treatment initiation (RR 2.2; p?<?0.001) and infrequent monitoring of serum potassium during a DDI (interval >48 h: RR 1.6; p?<?0.01).

Conclusion

Strategies for reducing the risk of hyperkalaemia during potassium-increasing DDIs should consider both patient- and physician-related risk factors.     

Changes in pro-inflammatory cytokines and body weight during 6-month risperidone treatment in drug naïve, first-episode schizophrenia

Objective

The present study aimed to examine the changes in pro-inflammatory cytokines and body weight during 6-month risperidone treatment in drug naïve, first-episode schizophrenia.

Methods

Sixty-two drug naïve, first-episode schizophrenia (SZ group) and 60 healthy individuals (control group) were enrolled in the study. Serum interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) levels, and body weight were measured at baseline for both groups, and repeated for the SZ group at five different time points during 6-month risperidone treatment.

Results

At baseline, serum IL-1β, IL-6, and TNF-α levels in the SZ group (53.28?±?12.62, 33.98?±?14.13, 50.08?±?12.86 pg/mL, respectively) were significantly higher than those in the control group (23.49?±?15.27, 15.53?±?7.16, 32.12?±?15.23 pg/mL, respectively) (p's?<?0.001). Within the SZ group, serum IL-1β levels decreased significantly at 2 weeks (48.02?±?16.00 pg/mL, p?<?0.01) and 1 month (44.70?±?16.63 pg/mL, p?<?0.001), but then gradually increased at 2 months (48.49?±?18.87 pg/mL), 3 months (50.59?±?18.48 pg/mL) and 6 months (53.64?±?16.22 pg/mL) to the levels comparable to baseline; serum IL-6 levels changed significantly over the course of treatment (p?=?0.001), but reached the levels comparable to baseline at 6 months (37.13?±?13.23 pg/mL); serum levels of TNF-α increased significantly at 3 months (55.02?±?16.69 pg/mL, p?<?0.01) and 6 months (58.69?±?13.57 pg/mL, p?<?0.001); steady and significant weight gain was observed at each follow-up time point (p's?<?0.001), from 56.71?±?9.25 kg at baseline to 62.72?±?9.53 kg at 6 months.

Conclusions

Risperidone treatment is associated with changes in serum pro-inflammatory cytokines levels and weight. There is an initial anti-inflammatory effect that reduces with treatment, potentially due to its weight gain side effect.     

The effect of reboxetine co-administration with olanzapine on metabolic and endocrine profile in schizophrenia patients

Rationale

We previously demonstrated that the addition of the selective norepinephrine reuptake inhibitor reboxetine attenuates olanzapine-induced weight gain. Using the same study sample, we also sought to determine whether reboxetine’s weight-attenuating effect was accompanied by a beneficial effect on metabolic and endocrine parameters relevant to antipsychotic-induced weight gain and obesity.

Method

Blood samples at baseline and at the end of the 6-week trial were available for 54 participants who participated in previous double-blind, placebo-controlled studies of reboxetine (4 mg BID) addition to olanzapine-treated schizophrenia patients. Fasting glucose, lipid profile, insulin, leptin, cortisol, dehydroepiandrosterone (DHEA), prolactin, and thyroid-stimulating hormone (TSH) were analyzed.

Results

In contrast to the olanzapine/placebo group, the olanzapine/reboxetine group exhibited a reduction in blood triglyceride (p?<?0.05) and leptin (p?<?0.05) levels, and elevation in cortisol (p?<?0.05) and DHEA (p?<?0.008) levels. No significant between-group differences were detected in the changes in cholesterol, glucose, insulin, TSH, and prolactin.

Conclusions

Reboxetine addition resulted in meaningful improvement of some metabolic and endocrine measures associated with olanzapine-induced weight gain. The potential role of reboxetine in the prevention of olanzapine-induced weight gain and cardio–metabolic morbidity merits further large-scale, long-term investigation.     

Effects of caffeine and alcohol on mood and performance changes following consumption of lager

Rationale

The present study examined whether caffeine would modify the behavioural effects of alcohol.

Objectives

The aim of the study was to determine whether caffeine modifies the effects of alcohol on mood and psychomotor performance and to identify possible dose–response and temporal relationships.

Methods

A double-blind study examined the effects of three successive lager drinks (330 ml each) in the early afternoon on mood and psychomotor performance assessed at 30-min intervals over a 2-h period. Participants carried out a baseline session and were then randomly assigned to one of six conditions formed by combining three different doses of caffeine (0, 62.5 and 125 mg per drink) with either no alcohol or 4.3 % alcohol. One hundred and forty-six young adults (65 male, 81 female; age range 18–30 years) participated in the study. Mood (alertness, hedonic tone and anxiety) was assessed before and after performing simple reaction time and choice reaction time tasks.

Results

Alcohol was associated with higher hedonic tone (p?<?0.005), reduced anxiety (p?<?0.05) and reduced alertness (p?<?0.005). Caffeine had no modifying effect on hedonic tone or anxiety. However, the highest dose of caffeine did remove the effect of alcohol on alertness (p?<?0.05). Effects of alcohol and caffeine were found on the performance tasks (all p values?<?0.05) but these were independent effects.

Conclusions

The results from the present study confirm that caffeine does not remove the negative effects of alcohol on performance although high doses counteract the drop in subjective alertness produced by alcohol.     

Responsiveness to low-dose warfarin associated with genetic variants of VKORC1, CYP2C9, CYP2C19, and CYP4F2 in an Indonesian population

Purpose

The aim of this study was to assess the pharmacokinetics and pharmacodynamics of warfarin associated with genetic polymorphisms in VKORC1, CYP2C9, CYP2C19, and CYP4F2 in Indonesian patients treated with low-dose warfarin.

Methods

Genotyping of VKORC1, CYP2C9, CYP2C19, and CYP4F2 was carried out in 103 patients treated with a daily dose of 1–2 mg warfarin, 89 of whom were treated with a fixed daily dose of warfarin (1 mg). The plasma concentrations of S- and R-warfarin and S- and R-7-hydroxywarfarin were used as pharmacokinetic indices, while prothrombin time expressed as the international normalized ratio (PT-INR) was used as a pharmacodynamic index.

Results

In patients treated with a fixed daily dose of warfarin (1 mg), a higher PT-INR was associated with VKORC1-1639 AA [median 1.35; interquartile range (IQR)?1.21–1.50] than with the GA (1.18; IQR?1.12–1.32; p?<?0.01) and GG (1.02; IQR?=?1.02–1.06; p?<?0.01) polymorphisms, and with CYP2C9*1/*3 (1.63; IQR?1.45–1.85) compared to *1/*1 (1.23; IQR??1.13–1.43; p?<?0.05). The S-warfarin concentration was significantly higher in patients with CYP2C9*1/*3 than in those with *1/*1 (p?<?0.05). With low-dose warfarin administration, there was no significant difference in the concentrations of warfarin metabolites among any of the genotype variants. The genotype variations of CYP2C19 and CYP4F2 were not significantly associated with the PT-INR.

Conclusion

For low-dose warfarin treatment, the VKORC1-1639 G?>?A and CYP2C9 genotype variations affected the pharmacokinetics and pharmacodynamics of warfarin, while we could not find significant effects of CYP4F2 or CYP2C19 genotype variations on warfarin (metabolite) concentrations or PT-INR.