Use of proton pump inhibitors and risk of iron deficiency: a population-based case-control study.

BACKGROUND: Hypochlorhydric states are an important cause of iron deficiency (ID). Nevertheless, the association between therapy with proton pump inhibitors (PPIs) and ID has long been a subject of debate. This case-control study aimed to investigate the risk of ID associated with the use of PPIs using the UK Clinical Practice Research Datalink (CPRD) database. METHODS: Cases were patients aged 19 years or older with first-time diagnosis of ID between 2005 and 2016 (n = 26 806). The dates of first diagnosis of ID in cases defined the index dates. For each case, one control was matched by age, gender and general practice. A PPI "full" user (PFU) was defined as a subject who had received PPIs for a continuous duration of at least 1 year prior to the index date. A PPI "limited" users (PLU) was a subject who intermittently received PPI therapy. A PPI non-user (PNU) was a subject who received no PPI prescriptions prior to the index date. The odds ratio of ID in PFU and PLU compared to PNU was estimated using conditional logistic regression. RESULTS: Among cases, 2960 were PFU, 6607 PLU and 17 239 PNU. Among controls, 1091 were PFU, 5058 PLU and 20 657 PNU. Adjusted odds ratio of ID in PFU and PLU compared to PNU was 3.60 (95%CI, [3.32-3.91]) and 1.51 (95% CI, [1.44-1.58]). Positive dose-response and time-response relationships were observed. CONCLUSIONS: Chronic PPI use increases the risk of ID. Physicians should consider this when balancing the risks and benefits of chronic PPI prescription.

Essential diseases in prescribing: A national Delphi study towards a core curriculum in pharmacotherapy education.

AIMS: Prescribing is a core skill for junior doctors, yet 8-10% of their prescriptions contain errors. To ensure adequate training in prescribing, it is important to define the diseases for which junior doctors should be competent to prescribe. The aim of the present study was therefore to identify the essential diseases in prescribing for junior doctors. METHODS: A two-round Delphi consensus study was conducted among medical specialists, general practitioners, junior doctors, pharmacists and pharmacotherapy teachers from all eight academic hospitals in the Netherlands. Using a five-point Likert scale, the participants indicated for each item on an initial questionnaire whether it should be considered an essential disease for junior doctors. The items for which ≥80% of all respondents agreed or strongly agreed were accepted as essential diseases. RESULTS: Sixty-two participants completed the Delphi survey. In total, 63 of 220 items were considered to be essential diseases. CONCLUSION: This is the first Delphi consensus study identifying exact conditions that junior doctors must be able to prescribe for. The essential diseases can be used for training in prescribing and assessment of junior doctors' prescribing competence.

Should patients prescribed long-term low-dose aspirin receive proton pump inhibitors? A systematic review and meta-analysis.

BACKGROUND: Several clinical guidelines recommend the use of proton pump inhibitors (PPIs) in patients taking low-dose aspirin but report no or limited supporting data. We conducted a systematic review and meta-analysis to examine the effects of co-administration of PPIs in patients taking low-dose aspirin on the risks of adverse gastrointestinal (GI) and cardiovascular (CV) events, and on patient adherence to aspirin. METHODS: We searched PUBMED, EMBASE and Cochrane Central Register of Controlled Trials databases for relevant articles published through November 2013. We included randomised controlled trials (RCTs) and observational studies in patients taking low-dose aspirin with and without PPIs. Risk of bias was assessed using the Cochrane Collaboration's tool (for RCTs) and the Newcastle-Ottawa Scale (for observational studies). Pooled risk ratios (RRs) were computed using a random-effects model. RESULTS: We included 13 studies, of which 12 (2 RCTs and 10 observational studies) reported on GI events, and one (cohort study) on both GI bleeding and CV events. No study reported on adherence to aspirin. Co-administration of PPIs in patients receiving low-dose aspirin was associated with risk reductions of 73% (RR 0.27, 95% CI 0.17-0.42) and 50% (RR 0.50, 95% CI 0.32-0.80) in the occurrence of peptic ulcer and GI bleeding respectively. There was evidence of bias in publications reporting on the GI events. CONCLUSIONS: The practice of co-prescribing PPIs in patients taking low-dose aspirin is supported by some data, but the evidence is rather weak. It currently remains unclear whether the benefits of co-administration of PPIs in users of low-dose aspirin outweigh their potential harms.

Does the unfavorable pharmacokinetic and pharmacodynamic profile of the iNOS inhibitor GW273629 lead to inefficacy in acute migraine?

The objective of this study was to investigate the pharmacodynamics and pharmacokinetics of a single dose of GW273629, a selective iNOS inhibitor, given during and outside a migraine attack. GW273629 1500 mg was administered to 15 migraine patients both ictally and interictally. Nasal and exhaled nitric oxide (NO), plasma 3-nitrotyrosine, and nitrates were measured to assess systemic NO production. In addition, pharmacokinetics and treatment response were assessed. Data are mean (95% confidence interval [CI]). Plasma 3-nitrotyrosine was higher ictally: 11.96 (8.22, 15.71) ictally versus 2.74 (2.24, 3.24) ng/10 mg interictally (P < .0001). Exhaled and nasal NO showed a similar trend: 12.5 (6.5, 18.6) and 62.2 (41.5, 82.8) ppb ictally versus 9.9 (6.3, 13.4) ppb and 52.5 (38.5, 66.0) ppb interictally, respectively. Early absorption of GW273629 (AUC(0-2) [90% CI]) was reduced by 41 (22, 55)% during an attack. There was no improvement of headache or associated symptoms. Migraine headache is associated with reduced early absorption of GW273629 and excess NO production. In this open-label study, GW273629 was ineffective in the treatment of acute migraine.

Calcitonin gene-related peptide8-37 antagonizes capsaicin-induced vasodilation in the skin: evaluation of a human in vivo pharmacodynamic model.

The purpose of this study was to identify the mediators involved in capsaicin-induced vasodilation in the human skin and to evaluate a pharmacodynamic model for the early clinical evaluation of calcitonin gene-related peptide (CGRP) receptor antagonists. Dermal blood flow (DBF) response of the forearm skin to topically applied capsaicin was measured using laser Doppler perfusion imaging in 22 subjects. The effect of intra-arterially administered CGRP(8-37) (1200 ng . min(-1) . dl(-1) forearm), indomethacin (5 mug . min(-1) . dl(-1) forearm), and N(G)-monomethyl-l-arginine (l-NMMA; 0.2 mg . min(-1) dl(-1) forearm), and orally administered aprepitant (375 mg) on capsaicin-induced dermal vasodilation was assessed. Furthermore, the diurnal variation of the DBF response to capsaicin was studied. CGRP(8-37) inhibited the capsaicin-induced DBF increase: 217(145, 290)% in infused versus 370 (254, 486)% in the noninfused arm [mean (95% CI); p = 0.004]. In contrast, indomethacin, l-NMMA, aprepitant, and the time of assessment did not affect the DBF response to capsaicin. Thus, capsaicin-induced vasodilation in the human forearm skin is largely mediated by CGRP, but not by vasodilating prostaglandins, nitric oxide, or substance P. The response to capsaicin does not display a circadian rhythm. A pharmacodynamic model is proposed to evaluate CGRP receptor antagonists in humans in vivo.

Increased C-reactive protein in young adult patients with migraine.

Interictal serum C-reactive protein (CRP) was measured in 50 young adult patients with migraine and compared with 50 controls. The median CRP level was 1.42 mg/l in patients with migraine and 0.90 mg/l in controls (P = 0.03). This finding supports the role of inflammation in migraine, but needs confirmation in larger controlled studies. Prospective studies may establish whether measurements of CRP can identify patients with migraine at risk for cardiovascular events.

Reproducibility of the capsaicin-induced dermal blood flow response as assessed by laser Doppler perfusion imaging.

AIMS: Part I: to establish the dose and appropriate application site of capsaicin on the human forearm in order to produce a robust and reproducible dermal blood flow (DBF) response. Part II: to evaluate the within-subject arm-to-arm and period-to-period reproducibility. METHODS: Both parts consisted of two study visits. In part I, placebo and 100, 300 and 1000 microg capsaicin were applied at four predefined sites on the volar surface of both forearms. Placebo and capsaicin doses were randomized and balanced by site between subjects. Changes in DBF were assessed by laser Doppler perfusion imaging up to 60 min after capsaicin application. In part II, only 1000 microg capsaicin was applied on the proximal forearm and changes in DBF assessed up to 30 min (t(30)). DBF response was expressed as percent change from baseline +/- SD and the corresponding AUC(0-30). Reproducibility assessment included calculation of the concordance correlation coefficient (CCC). RESULTS: Part I (n = 12 subjects): compared with placebo, 300 and 1000 microg capsaicin increased DBF (P < 0.05) at all time points except at 10 min. This increase was reproducible at the two most proximal sites from the 30-min time point onwards when compared between arms (CCC >or= 0.8, i.e. substantial to almost perfect reproducibility). In part II (n = 11), t(30) averaged 390 +/- 120% and arm-to-arm reproducibility was almost perfect (CCC = 0.91) for AUC(0-30). CONCLUSIONS: Capsaicin induces a reproducible within-subject arm-to-arm increase in DBF. We provide a non-invasive pharmacodynamic model in humans to test antagonists of mediators involved in capsaicin-induced dermal vasodilation, including calcitonin gene-related peptide antagonists.

Non-invasive assessment of selective 5-HT(1B/1D)-receptor agonist-induced peripheral vascular effects in humans: comparison of different techniques.

OBJECTIVE: To compare the sensitivity of three non-invasive techniques for detecting serotonin (5-HT)(1B/1D)-receptor agonist-induced peripheral vascular effects in humans: the measurement of (1) systolic (SBP) and diastolic (DBP) blood pressures, (2) dorsal hand vein (DHV) diameter and (3) toe-arm systolic blood pressure gradient (DeltaSBP(toe-arm)). METHODS: A double-blind, placebo-controlled, three-way, cross-over study was performed in 12 healthy male volunteers. According to a randomly assigned allocation schedule, subjects were administered sumatriptan 3 mg, sumatriptan 6 mg or placebo subcutaneously. Measurements were performed at baseline, every 5 min for 30 min and at 40 min and 60 min after drug administration. SBP and DBP were recorded using a semi-automated oscillometric device. DHV diameter was measured using a linear variable differential transformer. DeltaSBP(toe-arm) was calculated after measuring toe and arm SBP with a strain-gauge technique. Sensitivity was evaluated with responsiveness statistics. RESULTS: Based on weighted mean and compared with placebo, sumatriptan 3 mg and 6 mg increased SBP by 3.3 mmHg ( P=0.023) and 6.4 mmHg ( P<0.001) and DBP by 5.0 mmHg ( P=0.006) and 7.5 mmHg ( P<0.001), respectively. Sumatriptan 3 mg and 6 mg decreased DHV diameter by 36% ( P=0.015) and 40% ( P=0.005), respectively. DeltaSBP(toe-arm) did not change. Peak changes were observed within 10-15 min after drug administration. The rank order of responsiveness was: BP > DHV diameter > DeltaSBP(toe-arm.) CONCLUSIONS: Clinically relevant doses of subcutaneous sumatriptan increased blood pressure and decreased DHV diameter without affecting DeltaSBP(toe-arm). The increase in blood pressure appeared to be dose dependent. Compared with DHV diameter and DeltaSBP(toe-arm), blood pressure measurement appeared to be the most sensitive technique for detecting selective 5-HT(1B/1D)-receptor agonist-induced peripheral vascular effects in humans.

Does B-mode common carotid artery intima-media thickness differ from M-model?

An increased intima-media thickness of the common carotid artery is thought to be an early sign of atherosclerosis. Both B- and M-mode ultrasonographic techniques are used to measure the intima-media thickness of the common carotid artery (B-IMT and M-IMT, respectively). The present study compares intima-media thickness of the common carotid artery measured with the two techniques. Intima-media thickness was measured in a random population sample of 250 subjects. Comparison was made by mean and 95% confidence intervals of differences between B-IMT and M-IMT, by linear regression analysis, and by intraclass and concordance correlation coefficients. M-IMT was + 0.011 +/- 0.091 mm (95% confidence intervals: -0.167 to + 0.188 mm) larger than B-IMT, which was 0.661 +/- 0.136 mm (range: 0.380 to 1.120 mm). Intraclass and concordance correlation coefficients were 0.802 and 0.801, respectively. In conclusion, acceptable agreement exists between the two methods and there was no important systematic difference between B-IMT and M-IMT.

Non-invasive assessment of local arterial pulse pressure: comparison of applanation tonometry and echo-tracking.

OBJECTIVES: Pulse pressure is not constant throughout the arterial tree. Use of pulse pressure at one arterial site as surrogate for pulse pressure at another arterial site may be erroneous. The present study compares three non-invasive techniques to measure local pulse pressure: (i) internally calibrated readings from applanation tonometry, (ii) alternative calibration of pressure waves obtained with applanation tonometry and (iii) alternative calibration of arterial distension waves obtained with echo-tracking. Alternative calibration assumes mean and diastolic blood pressure constant throughout the large artery tree. DESIGN AND METHODS: Study 1 used invasive measurements in the ascending aorta as a reference method and internally calibrated tonometer readings and alternatively calibrated pressure waves at the common carotid artery as test methods. Study 2 used alternatively calibrated pressure waves as a reference method and alternatively calibrated distension waves and internally calibrated applanation tonometer readings as test methods. RESULTS: In study 1, pulse pressure from internally calibrated tonometer readings was 10.2+/-14.3 mmHg lower and pulse pressure from alternatively calibrated pressure waves was 1.8+/-5.2 mmHg higher than invasive pulse pressure. Pulse pressure from calibrated distension waves was 3.4+/-6.9 mmHg lower than pulse pressure from alternatively calibrated pressure waves. According to British Hypertension Society criteria, pulse pressure from the internally calibrated tonometer achieved grade D and pulse pressure from alternatively calibrated pressure waves achieved grade A. Pulse pressure from calibrated distension waves achieved grade B when alternatively calibrated pressure waves were used as a reference method. CONCLUSIONS: Pulse pressure obtained from alternatively calibrated tonometer-derived pressure waves and echo-tracking-derived distension waves demonstrates good accuracy. Accuracy of pulse pressure from internally calibrated applanation tonometer readings at the carotid artery is poor.

Impact of antihypertensive treatment on quality of life: comparison between bisoprolol and bendrofluazide.

OBJECTIVES: To compare quality of life with the selective beta1-blocker bisoprolol and the thiazide diuretic bendrofluazide in patients with mild to moderate hypertension. DESIGN AND SETTING: Multi centric, randomised, double-blind, two-way crossover study carried out at six general practice centres. SUBJECTS: Eighty-one patients with newly diagnosed or previously treated hypertension, who had a mean diastolic blood pressure (BP) of 95-120 mm Hg after receiving placebo for 4-6 weeks. INTERVENTIONS: In random order, patients received bisoprolol (5 mg once daily) or bendrofluazide (2. 5 mg once daily) for 8 weeks. MAIN OUTCOME MEASURES: Quality of life and antihypertensive effect. RESULTS: Decrease in systolic/diastolic BP did not differ between bisoprolol (10 +/- 2/13 +/- 1 mm Hg) and bendrofluazide (9 +/- 2/11 +/- 1 mm Hg). Between bisoprolol and bendrofluazide neither in the intention-to-treat nor in the efficacy analysis any difference was found in quality of life variables, such as Health Status Index, somatic symptoms, anxiety, depression, total psychiatric morbidity, cognitive symptoms and hostility score. Compared to baseline the Health Status Index improved (P < 0.05) during bisoprolol. None of the other investigated quality of life variables changed compared to baseline. No patients dropped out during bisoprolol or bendrofluazide treatment. Although, the total number of reported adverse events appeared lower during bendrofluazide than during bisoprolol treatment, it is unclear whether drug related adverse events also differ between the two drugs. CONCLUSIONS: At equipotent antihypertensive dosages, the effect of an 8-week treatment on quality of life does not differ between the selective beta1-blocker bisoprolol and the thiazide diuretic bendrofluazide.

Quality of life comparison between bisoprolol and nifedipine retard in hypertension.

Quality of life with the selective beta1-blocker bisoprolol and the calcium channel blocker nifedipine as a retard formulation was compared in patients with essential hypertension. A multicenter randomized, double-blind, two-way, crossover study design was used. After a placebo run-in period (4-6 weeks), during which all antihypertensive therapy was withdrawn, 82 patients were randomized. During the active treatment periods (8 weeks each), patients received either bisoprolol once daily or nifedipine retard twice daily, using the double-dummy technique. A washout period (4-6 weeks) separated the treatment periods. Data at baseline (at randomization) and at the end of each treatment period were compared. Seventy-five patients completed the study. Blood pressure (168 +/- 2/103 +/- 1 mmHg) decreased (p < 0.001) similarly with bisoprolol (153 +/- 2/90 +/- 1 mmHg) and nifedipine (154 +/- 2/90 +/- 1 mmHg). Compared with baseline values, none of the quality of life variables investigated changed during bisoprolol or nifedipine retard use. Neither in the intention-to-treat nor the efficacy analysis were differences between bisoprolol and nifedipine found in quality of life variables, such as the Health Status Index, somatic symptoms, anxiety, depression, total psychiatric morbidity, cognitive symptoms, and hostility score. Only in the efficacy analysis did Health Status Index tend to be better (p = 0.055) during nifedipine intake when compared with bisoprolol. This trend was not present in the intention-to-treat analysis. The number of dropouts during bisoprolol (n = 2) and nifedipine (n = 3) treatment, and the number of patients reporting side effects (21% and 16%, respectively) did not differ (p = 0.64) between both treatments. It can be concluded that at equipotent antihypertensive dosages, an 8-week treatment period with the selective beta1-blocker bisoprolol or the calcium antagonist nifedipine as a retard formulation does not result in any difference in quality of life variables. It is not clear whether the trend of Health Status Index to become better during nifedipine intake, which was only found in the efficacy analysis and not in the intention-to-treat analysis, is of clinical relevance.