Associations between coping style, illness perceptions and self-reported symptoms after mild traumatic brain injury in prospectively studied pre-morbidly healthy individuals

This study investigated whether coping style and/or illness perceptions are related to the severity of self-reported post-concussion syndrome (PCS) symptoms in the post-acute period after mild traumatic brain injury (mTBI). We hypothesised that reporting of early and late enduring-type PCS symptomatology (self-reported symptoms) would be significantly and negatively associated with: (a) an active "approach" coping style and (b) the belief that the injury would have negative consequences on the respondent's life. Using a prospective observational design we assessed 61 pre-morbidly healthy individuals who were admitted to hospital after an mTBI. Participants were assessed with measures of coping style and illness perception as well as PCS, depressive, anxiety and post-traumatic stress symptomatology. After controlling for current psychological distress, approach coping style significantly and independently predicted the severity of self-reported symptoms for early-type PCS symptomatology, but not late enduring-type PCS symptoms. The extent to which the respondent believed their symptoms were due to the mTBI significantly and independently predicted both early and late enduring-type PCS symptoms. This study indicates that different patterns of coping and illness perceptions are associated with early vs. late enduring types of PCS symptoms; this may have implications for the treatment of post-injury self-reported symptoms.

Effect of companion presence on maternal satisfaction during neuraxial catheter placement for labor analgesia: a randomized clinical trial

BACKGROUND

Neuraxial labor analgesia is frequently achieved after placing an epidural catheter under sterile conditions. There is no consensus on the risk versus benefit of allowing a parturient's companion to remain during the procedure. We sought to assess the effect of the presence of a companion on maternal satisfaction and anxiety during neuraxial catheter placement for labor analgesia.

METHODS

Healthy nulliparous parturients planning to receive neuraxial labor analgesia after admission to labor, and who had a companion with them at the time of interview, were randomized to having a companion present or not present in the labor and delivery room during neuraxial catheter placement. Participants completed questionnaires to assess maternal anxiety, pain catastrophizing and health literacy. Satisfaction was scored on 5-point Likert scale (1- highly dissatisfied, 2- dissatisfied, 3- neutral, 4- satisfied, 5- highly satisfied).

RESULTS

A total of 143 participants completed the study. The Wilcoxon-Mann-Whitney odds ratio for a random pair of satisfaction scores for a woman with her companion present compared with companion not present was 1.93 (95% CI 1.30 to 2.81, P=0.001). Anxiety scores were decreased following the procedure (P=0.39) in both groups. Eighty-nine percent of women randomized to companion not present would have preferred to have a companion present (P <0.001) compared with only one with their companion present who would have preferred her companion to be not present (P=0.99).

CONCLUSION

Maternal satisfaction can be improved with the presence of a companion in the labor and delivery room at the time of neuraxial catheter placement for labor analgesia.

The effects of glycine on auditory mismatch negativity in schizophrenia

Glycine increases N-methyl-d-aspartate receptor (NMDAR) mediated glutamatergic function. Mismatch negativity (MMN) is a proposed biomarker of glutamate-induced improvements in clinical symptoms, however, the effect of glycine-mediated NMDAR activation on MMN in schizophrenia is not well understood. This study aimed to determine the effects of acute and 6-week chronic glycine administration on MMN in schizophrenia patients. MMN amplitude was compared at baseline between 22 patients (schizophrenia or schizoaffective disorder; receiving stable antipsychotic medication; multi-centre recruitment) and 21 age- and gender-matched controls. Patients underwent a randomised, double-blind, placebo-controlled clinical trial with glycine added to their regular antipsychotic medication (placebo, n=10; glycine, n=12). MMN was reassessed post-45-minutes of first dose (0.2g/kg) and post-6-weeks treatment (incremented to 0.6g/kg/day). Clinical symptoms were assessed at baseline and post-6-weeks treatment. At baseline, duration MMN was smaller in schizophrenia compared to controls. Acute glycine increased duration MMN (compared to placebo), whilst this difference was absent post-6-weeks treatment. Six weeks of chronic glycine administration improved PANSS-Total, PANSS-Negative and PANSS-General symptoms compared to placebo. Smaller baseline duration MMN was associated with greater PANSS-Negative symptoms and predicted (at trend level) PANSS-Negative symptom improvement post-6-weeks glycine treatment (not placebo). These findings support the benefits of chronic glycine administration and demonstrate, for the first time, that acute glycine improves duration MMN in schizophrenia. This result, together with smaller baseline duration MMN predicting greater clinical treatment response, suggests the potential for duration MMN as a biomarker of glycine-induced improvements in negative symptoms in schizophrenia.

The Social Regulation of Pain: Autonomic and Neurophysiological Changes Associated With Perceived Threat

The analgesic effect of social support is proposed as a function of social support modulating perceived threat of painful stimuli. In the current study, we directly examined the social buffering effect in the context of the threat of pain. Eighteen healthy participants were subjected to the threat of pain while they held the hand of a close other, a stranger, or not at all. Neural and autonomic responses were recorded using electroencephalogram and heart rate, respectively. Close other hand-holding reduced pain perception. This was accompanied by decreased heart rate and frontal theta oscillation (4-8 Hz) during the threat phase preceding painful stimulation. Interestingly, decreased heart rate and frontal theta in the close other hand-holding condition were uniquely associated with greater pain reduction during subsequent nociceptive stimulation. Neural changes were source-localized to the insular cortex and the rostral-ventral portions of anterior cingulate cortex, regions involved in the processing of threat and pain. Together, our data build upon work to date linking social support to pain by showing autonomic and neurophysiological changes associated with pain reduction.

PERSPECTIVE

Social support may reduce pain through buffering the autonomic and neurophysiological response to the threatening quality of noxious stimuli. Results implicate that in clinical settings the caregiver could help people with chronic pain reappraise pain and related conditions as less stressful.

Transcutaneous Carbon Dioxide Measurements in Women Receiving Intrathecal Morphine for Cesarean Delivery: A Prospective Observational Study

BACKGROUND

Neuraxial morphine is the most commonly used analgesic technique after cesarean delivery. The incidence of respiratory depression is reported to be very low (0%-1.2%) in this patient population as measured by pulse oximetry and respiratory rates. However, hypercapnia may be a more sensitive measure of respiratory depression. In the current study, the incidence of hypercapnia events (transcutaneous CO2 [TcCO2] >50 mm Hg) for ≥2-minute duration was evaluated using the Topological Oscillation Search with Kinematical Analysis monitor in women who received intrathecal morphine for postcesarean delivery analgesia.

METHODS

Healthy women (>37 weeks of gestation) scheduled for a cesarean delivery with spinal anesthesia with intrathecal morphine were recruited. Baseline STOP-BANG sleep apnea questionnaire and TcCO2 readings were obtained. Spinal anesthesia was initiated with 12 mg hyperbaric bupivacaine, 15 µg fentanyl, and 150 µg morphine. The Topological Oscillation Search with Kinematical Analysis monitor was reapplied in the postanesthesia care unit and TcCO2 measurements obtained for up to 24 hours. Supplemental opioid administration and adverse respiratory events were recorded. The primary outcome was the incidence of hypercapnia events, defined as a TcCO2 reading >50 mm Hg for ≥2 minutes in the first 24 hours after delivery.

RESULTS

Of the 120 women who were recruited, 108 completed the study. Thirty-five women (32%; 99.15% confidence interval, 21%-45%) reached the primary outcome of a sustained hypercapnia event. The median time (interquartile range [IQR]) from intrathecal morphine administration to the hypercapnia event was 300 (124-691) minutes. The median (IQR) number of events was 3 (1-6) and longest duration of an event was 25.6 (8.4-98.7) minutes. Baseline median (IQR) TcCO2 measurements were 35 (30-0) mm Hg and postoperatively, median (IQR) TcCO2 measurements were 40 (36-43) mm Hg, a difference of 5 mm Hg (99.15% confidence interval of the difference 2-8 mm Hg, P < .001). The incidence of hypercapnia events was 5.4% in women with a baseline TcCO2 value ≤31 mm Hg, 22.5% with a baseline TcCO2 between 32 and 38 mm Hg, and 77.4% with a baseline TcCO2 >38 mm Hg (P < .001).

CONCLUSIONS

Hypercapnia events (>50 mm Hg for ≥2-minute duration) occurred frequently in women receiving 150 μg intrathecal morphine for postcesarean analgesia. Higher baseline TcCO2 readings were observed in women who had hypercapnia events.

Utility of event-related potentials in predicting antidepressant treatment response: An iSPOT-D report

It is essential to improve antidepressant treatment of major depressive disorder (MDD) and one way this could be achieved is by reducing the number of treatment steps by employing biomarkers that can predict treatment outcome. This study investigated differences between MDD patients and healthy controls in the P3 and N1 component from the event-related potential (ERP) generated in a standard two-tone oddball paradigm. Furthermore, the P3 and N1 are investigated as predictors for treatment outcome to three different antidepressants. In the international Study to Predict Optimized Treatment in Depression (iSPOT-D)--a multi-center, international, randomized, prospective practical trial--1008 MDD participants were randomized to escitalopram, sertraline or venlafaxine-XR. The study also recruited 336 healthy controls. Treatment response and remission were established after eight weeks using the 17-item Hamilton Rating Scale for Depression. P3 and N1 latencies and amplitudes were analyzed using a peak-picking approach and further replicated by using exact low resolution tomography (eLORETA). A reduced P3 was found in MDD patients compared to controls by a peak-picking analysis. This was validated in a temporal global field power analysis. Source density analysis revealed that the difference in cortical activity originated from the posterior cingulate and parahippocampal gyrus. Male non-responders to venlafaxine-XR had significantly smaller N1 amplitudes than responders. This was demonstrated by both analytical methods. Male non-responders to venlafaxine-XR had less activity originating from the left insular cortex. The observed results are discussed from a neural network viewpoint.

Characterization of RIPK3-mediated phosphorylation of the activation loop of MLKL during necroptosis

Mixed lineage kinase domain-like pseudokinase (MLKL) mediates necroptosis by translocating to the plasma membrane and inducing its rupture. The activation of MLKL occurs in a multimolecular complex (the 'necrosome'), which is comprised of MLKL, receptor-interacting serine/threonine kinase (RIPK)-3 (RIPK3) and, in some cases, RIPK1. Within this complex, RIPK3 phosphorylates the activation loop of MLKL, promoting conformational changes and allowing the formation of MLKL oligomers, which migrate to the plasma membrane. Previous studies suggested that RIPK3 could phosphorylate the murine MLKL activation loop at Ser345, Ser347 and Thr349. Moreover, substitution of the Ser345 for an aspartic acid creates a constitutively active MLKL, independent of RIPK3 function. Here we examine the role of each of these residues and found that the phosphorylation of Ser345 is critical for RIPK3-mediated necroptosis, Ser347 has a minor accessory role and Thr349 seems to be irrelevant. We generated a specific monoclonal antibody to detect phospho-Ser345 in murine cells. Using this antibody, a series of MLKL mutants and a novel RIPK3 inhibitor, we demonstrate that the phosphorylation of Ser345 is not required for the interaction between RIPK3 and MLKL in the necrosome, but is essential for MLKL translocation, accumulation in the plasma membrane, and consequent necroptosis.

Antibacterial validation of electrogenerated hypochlorite using carbon-based electrodes

This proof-of-concept study explores the novel use of carbon-based electrodes for the electrochemical generation of hypochlorite and compares the antimicrobial efficacy against commercial hypochlorite solution. Antimicrobial concentrations of hypochlorite were generated using pad-printed carbon and carbon fibre electrodes, yielding up to 0·027% hypochlorite in 60 min and 0·1% hypochlorite in 15 min, respectively, in a nondivided assembly. The minimum inhibitory concentration (MIC) of the electrogenerated hypochlorite produced using carbon fibre electrodes was established for four medically important bacteria (Pseudomonas aeruginosa and Staphylococcus aureus approx. 0·025%, Escherichia coli and Enterococcus faecalis approx. 0·012%) and found to be in agreement with those determined using commercial hypochlorite solution. Therefore, carbon-based electrodes, particularly carbon fibre, have proven effective for the generation of antimicrobial concentrations of hypochlorite. The similarity of the MIC values to commercial hypochlorite solutions suggests that the antimicrobial efficacy is derived from the quantified hypochlorite generated and not due to marked cogeneration of reactive oxygen species, as identified for other assemblies. As such, the application of carbon electrodes may be suitable for the local production of hypochlorite for healthcare antisepsis.

SIGNIFICANCE AND IMPACT OF THE STUDY

Carbon fibre electrodes can rapidly generate antimicrobial concentrations of hypochlorite; as such, these cheap and commercially available electrodes are proposed for the local production of hypochlorite for healthcare antisepsis. Importantly, the antimicrobial properties of the electrochemically generated hypochlorite mirror those of commercial hypochlorite, suggesting this is not enhanced by the cogeneration of reactive oxygen species. This illustrates the potential use of disposable carbon electrodes for localized small-volume production of hypochlorite for surface and skin cleansing, and opens a broader scope of research into the exploitation of carbon electrodes for this application.

Hepatitis C Prevention and Needle Exchange Programs in Rhode Island: ENCORE

As Rhode Island's only needle exchange program, ENCORE (Education, Needle Exchange, Counseling, Outreach, and REferrals) serves a wide range of clients infected or at risk for infection with hepatitis C virus (HCV). Through its on-site and outreach platforms across Rhode Island, ENCORE is in a unique position to serve at-risk individuals who may not otherwise present for prevention, testing and care for HCV, as well as human immunodeficiency virus (HIV). In this article, we discuss the role of needle exchange programs in preventing HCV transmission, and provide an overview of the history and current operations of ENCORE.

A prospective cohort study of antipsychotic medications in pregnancy: the first 147 pregnancies and 100 one year old babies

BACKGROUND

Many women diagnosed with varying psychiatric disorders take antipsychotic medications during pregnancy. The safety of antipsychotic medications in pregnancy is largely unknown.

METHODS

We established the National Register of Antipsychotic Medications in Pregnancy in 2005. Women who are pregnant and taking an antipsychotic medication are interviewed every 6 weeks during pregnancy and then followed until their babies are one year old. The baby's progress is closely followed for the first year of life.

FINDINGS

As of April 18 2012, 147 pregnancies had been followed through to completion. There were 142 live births and data is available for 100 one year old babies. 18% of babies were born preterm, with a higher dose of antipsychotic medication correlating to an increased likelihood of premature delivery; 43% of babies required special care nursery or intensive care after birth; 37% had any degree of respiratory distress and 15% of babies developed withdrawal symptoms. Congenital anomalies were seen in eight babies. Most pregnancies resulted in the birth of live, healthy babies. The use of mood stabilisers or higher doses of antipsychotics during pregnancy increased the likelihood of babies experiencing respiratory distress or admission to Special Care Nursery or Neonatal Intensive Care Units.

CONCLUSION

There is a great need for safety and efficacy information about the use of antipsychotic medications in pregnancy. Live, healthy babies are the most common outcome following the use of antipsychotic medication in pregnancy, but clinicians should be particularly mindful of neonatal problems such as respiratory distress.

A four week randomised control trial of adjunctive medroxyprogesterone and tamoxifen in women with mania

Emerging research has suggested that hormone treatments such as selective oestrogen receptor modulators (SERMs) or progestins may be useful in the treatment of mania. The current pilot study compared the use of the SERM tamoxifen and the progestin medroxyprogesterone acetate (MPA), as an adjunct to mood stabiliser medications, for the treatment of mania symptoms in 51 women in a 28-day double blind, placebo controlled study. The primary outcome was the change between baseline and day 28 mania scores as measured by the Clinician Administered Rating Scale for Mania (CARS-M). Adjunctive MPA treatment provided greater and more rapid improvement in mania symptoms compared with adjunctive placebo and tamoxifen treatment. Adjunctive therapy with MPA may be a potentially useful new treatment for persistent mania, leading to a greater and more rapid resolution of symptoms compared with mood stabiliser treatment alone.

Home telemonitoring or structured telephone support programmes after recent discharge in patients with heart failure: systematic review and economic evaluation

BACKGROUND

Remote monitoring (RM) strategies have the potential to deliver specialised care and management to patients with heart failure (HF).

OBJECTIVE

To determine the clinical effectiveness and cost-effectiveness of home telemonitoring (TM) or structured telephone support (STS) strategies compared with usual care for adult patients who have been recently discharged (within 28 days) from acute care after a recent exacerbation of HF.

DATA SOURCES

Fourteen electronic databases (including MEDLINE, EMBASE, PsycINFO and The Cochrane Library) and research registers were searched to January 2012, supplemented by hand-searching relevant articles and contact with experts. The review included randomised controlled trials (RCTs) or observational cohort studies with a contemporaneous control group that included the following RM interventions: (1) TM (including cardiovascular implanted monitoring devices) with medical support provided during office hours or 24/7; (2) STS programmes delivered by human-to-human contact (HH) or human-to-machine interface (HM).

REVIEW METHODS

A systematic review and network meta-analysis (where appropriate) of the clinical evidence was carried out using standard methods. A Markov model was developed to evaluate the cost-effectiveness of different RM packages compared with usual care for recently discharged HF patients. TM 24/7 or using cardiovascular monitoring devices was not considered in the economic model because of the lack of data and/or unsuitability for the UK setting. Given the heterogeneity in the components of usual care and RM interventions, the cost-effectiveness analysis was performed using a set of costing scenarios designed to reflect the different configurations of usual care and RM in the UK.

RESULTS

The literature searches identified 3060 citations. Six RCTs met the inclusion criteria and were added to the 15 trials identified from the previous systematic reviews giving a total of 21 RCTs included in the systematic review. No trials of cardiovascular implanted monitoring devices or observational studies met the inclusion criteria. The methodological quality of the studies varied widely and reporting was generally poor. Compared with usual care, RM was beneficial in reducing all-cause mortality for STS HH [hazard ratio (HR) 0.77, 95% credible interval (CrI) 0.55 to 1.08], TM during office hours (HR 0.76, 95% CrI 0.49 to 1.18) and TM 24/7 (HR 0.49, 95% CrI 0.20 to 1.18); however, these results were statistically inconclusive. The results for TM 24/7 should be treated with caution because of the poor methodological quality of the only included study in this network. No favourable effect on mortality was observed with STS HM. Similar reductions were observed in all-cause hospitalisations for TM interventions, whereas STS interventions had no major effect. A sensitivity analysis, in which a study was excluded because it provided better-than-usual support to the control group, showed larger beneficial effects for most outcomes, particularly for TM during office hours. In the cost-effectiveness analyses, TM during office hours was the most cost-effective strategy with an estimated incremental cost-effectiveness ratio (ICER) of £11,873 per quality-adjusted life-year (QALY) compared with usual care, whereas STS HH had an ICER of £228,035 per QALY compared with TM during office hours. STS HM was dominated by usual care. Similar results were observed in scenario analyses performed using higher costs of usual care, higher costs of STS HH and lower costs of TM during office hours.

LIMITATIONS

The RM interventions included in the review were heterogeneous in terms of monitored parameters and HF selection criteria and lacked detail in the components of the RM care packages and usual care (e.g. communication protocols, routine staff visits and resources used). As a result, the economic model developed scenarios for different RM classifications and their costs were estimated using bottom-up costing methods. Although the users can decide which of these scenarios is most representative of their setting, uncertainties still remain about the assumptions made in the estimation of these costs. In addition, the model assumed that the effectiveness of the interventions was constant over time, irrespective of the duration of deployment, and that the intervention was equally effective in different age/severity groups.

CONCLUSION

Despite wide variation in usual care and RM strategies, cost-effectiveness analyses suggest that TM during office hours was an optimal strategy (in most costing scenarios). However, clarity was lacking among descriptions of the components of RM packages and usual care and there was a lack of robust estimation of costs. Further research is needed in these areas.

STUDY REGISTRATION

PROSPERO registration no. CRD42011001368.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Transversus abdominis plane infiltration for laparoscopic gastric banding: A pilot study

AIM: To estimate an effect size for the transversus abdominis plane (TAP) infiltration on quality of recovery in patients undergoing laparoscopic gastric band surgery.

METHODS: The pilot study was a randomized, double blinded, placebo controlled trial. Patients undergoing laparoscopic gastric band surgery were randomized to receive a bilateral TAP infiltration with 20 mL of 0.5% ropivacaine or saline. The evaluated outcomes included quality of recovery-40 (QoR-40) at 24 h, postoperative opioid consumption and pain. Data was examined using the Mann-Whitney U test.

RESULTS: Nineteen subjects were recruited. There was a positive trend favoring the TAP infiltration group in global QoR-40 scores at 24 h after surgery, median [interquartile range (IQR)] of 175.5 (170-189) compared to 170 (160-175) in the control group (P = 0.06). There also a positive trend toward a lower cumulative opioid consumption in the TAP infiltration group, median (IQR) of 7.5 (2.5-11.5) mg iv morphine equivalents compared to 13 (7-21.5) in the control group (P = 0.07). Correlation analysis (Spearman’s Rho) demonstrated an inverse relationship between 24 h cumulative opioid consumption and global QoR-40 scores, -0.49 (P = 0.03).

CONCLUSION: The use of multimodal analgesic techniques to reduce opioid related side effects is particularly desirable in morbidly obese patients undergoing gastric reduction surgery. The TAP infiltration seems to have a clinically important effect in reducing postoperative opioid consumption and improve quality of recovery after laparoscopic gastric band surgery in morbid obese patients. Future studies to confirm the beneficial effects of the TAP infiltration in these patients are warranted.

Virtual airway simulation to improve dexterity among novices performing fibreoptic intubation

We developed a virtual reality software application (iLarynx) using built-in accelerometer properties of the iPhone(®) or iPad(®) (Apple Inc., Cupertino, CA, USA) that mimics hand movements for the performance of fibreoptic skills. Twenty novice medical students were randomly assigned to virtual airway training with the iLarynx software or no additional training. Eight out of the 10 subjects in the standard training group had at least one failed (> 120 s) attempt compared with two out of the 10 participants in the iLarynx group (p = 0.01). There were a total of 24 failed attempts in the standard training group and four in the iLarynx group (p < 0.005). Cusum analysis demonstrated continued group improvement in the iLarynx, but not in the standard training group. Virtual airway simulation using freely available software on a smartphone/tablet device improves dexterity among novices performing upper airway endoscopy.

The microbiome-gut-brain axis during early life regulates the hippocampal serotonergic system in a sex-dependent manner

Bacterial colonisation of the intestine has a major role in the post-natal development and maturation of the immune and endocrine systems. These processes are key factors underpinning central nervous system (CNS) signalling. Regulation of the microbiome-gut-brain axis is essential for maintaining homeostasis, including that of the CNS. However, there is a paucity of data pertaining to the influence of microbiome on the serotonergic system. Germ-free (GF) animals represent an effective preclinical tool to investigate such phenomena. Here we show that male GF animals have a significant elevation in the hippocampal concentration of 5-hydroxytryptamine and 5-hydroxyindoleacetic acid, its main metabolite, compared with conventionally colonised control animals. Moreover, this alteration is sex specific in contrast with the immunological and neuroendocrine effects which are evident in both sexes. Concentrations of tryptophan, the precursor of serotonin, are increased in the plasma of male GF animals, suggesting a humoral route through which the microbiota can influence CNS serotonergic neurotransmission. Interestingly, colonisation of the GF animals post weaning is insufficient to reverse the CNS neurochemical consequences in adulthood of an absent microbiota in early life despite the peripheral availability of tryptophan being restored to baseline values. In addition, reduced anxiety in GF animals is also normalised following restoration of the intestinal microbiota. These results demonstrate that CNS neurotransmission can be profoundly disturbed by the absence of a normal gut microbiota and that this aberrant neurochemical, but not behavioural, profile is resistant to restoration of a normal gut flora in later life.

Bivalirudin for the treatment of ST-segment elevation myocardial infarction: a NICE single technology appraisal

The National Institute for Health and Clinical Excellence (NICE) invited the manufacturer (The Medicines Company) of bivalirudin to submit evidence for its clinical and cost effectiveness within its licensed indication for the treatment of adults with ST-segment elevation myocardial infarction (STEMI) intended for primary percutaneous coronary intervention (PPCI), as part of NICE's single technology appraisal (STA) process. The School of Health and Related Research (ScHARR) at the University of Sheffield was commissioned to act as the Evidence Review Group (ERG), which produced a review of the evidence within the manufacturer's submission to NICE. This article describes the manufacturer's submission, the ERG review and NICE's subsequent decisions. The main evidence was derived from one randomized controlled trial (RCT) of STEMI patients intended for PPCI, comparing bivalirudin with unfractionated heparin plus glycoprotein IIb/IIIa inhibitors (GPIs). Bivalirudin was associated with a significant reduction in cardiac mortality at 30 days (p = 0.03) and at 1-year follow-up (p = 0.005), and a significant reduction in major bleeding at 30 days (p < 0.001) and 1 year (p < 0.0001), compared with heparin plus GPI. Stent thrombosis up to 24 hours following PPCI was significantly (p < 0.001) more common with bivalirudin. However, there was no significant treatment effect for stent thrombosis from 1 to 30 days (p = 0.28), or at 1-year follow-up (p = 0.53). There were no significant treatment group differences at 30 days and at 1 year in stroke (p = 0.68 and p = 0.99, respectively), in myocardial infarction [MI] (p = 0.90 and p = 0.22, respectively), or in the need for the revascularization of the target vessel for ischaemia (p = 0.18 and p = 0.12, respectively). There were two decision-analytic models: the base-case scenario used 1-year follow-up data from the RCT; and a sensitivity analysis used 3-year follow-up data. Resource use was primarily drawn from this RCT. Health-related quality-of-life (HR-QOL) estimates were drawn from a UK cohort study. Both models evaluated the incremental costs and outcomes of bivalirudin compared with heparin plus GPI for patients with STEMI intended for PPCI. The analysis adopted a UK NHS perspective over a lifetime horizon. Unit costs were based on year 2009-2010 prices. The model adopted a decision-tree structure to reflect initial events for the initial period (stroke, repeat MI, minor/major bleeding events, repeat revascularization and death) and a two-state Markov component to simulate longer-term survival. The economic analysis suggested that bivalirudin is expected to dominate the heparin plus GPI strategy. This finding was consistent across the probabilistic sensitivity analysis and the vast majority of deterministic sensitivity analyses undertaken. Three exceptions to this finding were observed for the following sensitivity analyses: (1) the exclusive use of eptifibatide as the GPI (incremental cost-effectiveness ratio [ICER] = £1,764); (2) the combination of 100 % eptifibatide use, 100 % radial arterial access and no differential length between strategies for initial hospital stay (ICER = £4,106); and (3) a longer length of ward stay (increase of 0.33 days) for the initial hospitalization (ICER = £415). The Appraisal Committee (AC) gave a positive recommendation for bivalirudin for the treatment of adults with STEMI undergoing PPCI.

Inhibition of P-glycoprotein enhances transport of imipramine across the blood-brain barrier: microdialysis studies in conscious freely moving rats

BACKGROUND AND PURPOSE

Recent studies indicate that efflux of antidepressants by the multidrug resistance transporter P-glycoprotein (P-gp) at the blood-brain barrier (BBB) may contribute to treatment-resistant depression (TRD) by limiting intracerebral antidepressant concentrations. In addition, clinical experience shows that adjunctive treatment with the P-gp inhibitor verapamil may improve the clinical outcome in TRD. Therefore, the present study aimed to investigate the effect of P-gp inhibition on the transport of the tricyclic antidepressant imipramine and its active metabolite desipramine across the BBB.

EXPERIMENTAL APPROACH

Intracerebral microdialysis in rats was used to monitor brain levels of imipramine and desipramine following i.v. imipramine administration, with or without pretreatment with one of the P-gp inhibitors verapamil or cyclosporin A (CsA). Plasma drug levels were also determined at regular intervals.

KEY RESULTS

Pretreatment with either verapamil or CsA resulted in significant increases in imipramine concentrations in the microdialysis samples, without altering imipramine plasma pharmacokinetics. Furthermore, pretreatment with verapamil, but not CsA, led to a significant elevation in plasma and brain levels of desipramine.

CONCLUSIONS AND IMPLICATIONS

The present study demonstrated that P-gp inhibition enhanced the intracerebral concentration of imipramine , thus supporting the hypothesis that P-gp activity restricts brain levels of certain antidepressants, including imipramine. These findings may help to explain reports of a beneficial response to adjunctive therapy with verapamil in TRD.