Prescription-event Monitoring Study Research Articles

Prescription-Event Monitoring Study on Safety and Efficacy of Levonadifloxacin (Oral and I.V.) in Management of Bacterial Infections: Findings of Real-World Observational Study.

Background:Levonadifloxacin is a novel broad-spectrum antibiotic belonging to the benzoquinolizine subclass of quinolones. It is available in intravenous as well as oral formulation for the treatment of infections caused by common Gram-positive bacterial pathogens including methicillin-resistant Staphylococcus aureus (MRSA).Patients and Methods:This study retrospectively assessed the real-world safety and efficacy of levonadifloxacin (oral and/or IV) in the treatment of 1229 patients across various clinical conditions. Study outcomes were clinical and microbiological success at the end of therapy.Results:The mean duration of levonadifloxacin therapy was 7.2 days, with a time to clinical improvement averaging at 4 days. Three hundred and three patients received oral therapy, 875 received IV, and 51 received a combination of IV followed by oral therapy. Patients were prescribed levonadifloxacin for skin and soft-tissue infections, diabetic foot infections, septicemia, catheter-related bloodstream infections, bone and joint infections, febrile neutropenia, and respiratory infections including COVID-19 pneumonia. High clinical success rates of 98.3%, 93.7%, and 96.1% with oral, IV, and IV followed by oral levonadifloxacin, respectively, were obtained. Only 11 mild adverse events were reported in 9 patients which included constipation, diarrhea, hyperglycemia, nausea, fatigue, and vomiting. Overall, 96.3% and 97.3% of investigators rated the efficacy and safety of levonadifloxacin as “good to excellent.”Conclusions:An excellent safety and efficacy profile of levonadifloxacin was observed in this study making it a suitable treatment option for management of various bacterial infections, including those caused by resistant Gram-positive pathogens such as MRSA and quinolone-resistant S. aureus.

Risk of seizure associated with use of acid-suppressive drugs: An observational cohort study.

Previous, large, prescription-event monitoring studies in patients receiving PPI therapy recorded instances of convulsion or seizure. The objective of this study was to quantify the relative risk of seizure associated with the use of proton pump inhibitors (PPIs) and histamine-2 receptor antagonists (H2RAs) in a general population, overall and stratified by epilepsy status, and to determine the effects of demographics and comorbidities. In this observational study (NCT01744301), patients aged 20-84years in the study period from 1 January 2005 to 31 December 2011 were identified from The Health Improvement Network. In a nested case-control analysis, 8605 patients with seizure were matched to 40000 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression. After adjustment, there were no associations between current PPI use and seizure risk in the overall population (OR: 1.05; 95% CI: 0.87-1.27), the subcohort with epilepsy (OR: 0.87; 95% CI: 0.49-1.53), and the subcohort without epilepsy (OR: 1.05; 95% CI: 0.87-1.28). There were no associations between current H2RA use and seizure risk in the overall population (OR: 1.16; 95% CI: 0.62-2.18) and the subcohort without epilepsy (OR: 1.02; 95% CI: 0.51-2.01). Seizures were less frequent in women than in men. Dementia/psychosis, anxiety, depression, and use of anxiolytics, antidepressants, and paracetamol were associated with an increased seizure risk. Our study revealed that the use of PPIs and the use of H2RAs were not associated with an increased risk of seizures in the overall population or in the cohorts stratified by epilepsy status.

A prescription event monitoring study on the utility of garenoxacin, a newer fluoroquinolone in India.

Background:Prescription event monitoring (PEM) study is conducted worldwide. The main objective of such study is to monitor the adverse events when a drug is being prescribed in “real life clinical” settings. PEM studies are being looked upon as an essential observational tool of postmarketing surveillance. Garenoxacin, a newer fluoroquinolone offers an excellent spectrum of antimicrobial coverage, which includes Gram-positive, Gram-negative, anaerobes and atypical microorganism. This broad spectrum of activity is attributed to its unique structure.Aim:The aim was to assess the safety profile of garenoxacin in Indian settings.Materials and Methods:A total of 400 doctors across the country participated in the study. Data from 12,498 patients was obtained. Monitoring of each patient was done for any adverse events.Results:As an initial line of therapy garenoxacin was preferred in majority of cases of community-acquired pneumonia (CAP) and acute exacerbations of chronic bronchitis. Adverse events were reported in 159 patients which included 0.5% cases with nausea/vomiting, 0.1% cases with diarrhea. Central nervous system side-effects like drowsiness or dizziness was reported in 0.02% of the cases. All the adverse events were of mild to moderate severity and did not require hospitalization.Conclusion:Garenoxacin a novel desfluoroquinolone appears to be an ideal antimicrobial agent for the treatment of various respiratory tract infections including CAP. With superior safety profile, excellent antimicrobial coverage and a convenient once a day dosing garenoxacin appears to improve the patient compliance.

Strategy support for the Post‐Market Monitoring (PMM) of GM plants: Review of existing PMM strategies developed for the safety assessment of human and animal health

Strategy support for the Post‐Market Monitoring (PMM) of GM plants: Review of existing PMM strategies developed for the safety assessment of human and animal health

A Prescription event monitoring (PEM) study to assess safety and health outcomes of Airtec SF (Salmeterol Fluticasone propionate combination) in Indian population

Background: Asthma management has been fraught with several challenges especially for partly or uncontrolled cases. Incremental dosage strategy with salmeterol, fluticasone propionate combination offers stable yet effective control of symptoms preventing further exacerbations. However, there is limited evidence available on the need and safety profile of this incremental dosage strategy with the combination especially in Indian settings. To examine the safety and adverse clinical outcomes of Airtec SF when prescribed in patients with well- or poorly controlled persistent asthma. Methods: Based on the principle of prescription event monitoring (PEM) for safety reporting, this study was conducted at 20 centers across India. PEM study booklets with study questionnaire were provided to capture information related to adverse “events” during the observation period of 30 days. Results: Data of 384 patients were analyzed, with a mean age 44.5 years. 39% (n=150) were newly diagnosed and 61% (n=234) being in poorly controlled asthma status (i.e., partly or uncontrolled asthma). Of them, 42% (161), 44% (n=169) and 14% (54) patients were diagnosed with mild, moderate or severe persistent asthma, respectively. These were prescribed with metered-dose inhaler (n=187) or dry powder inhaler (n=197) formulations. 56% (n=216) patients suffered from concomitant allergic rhinitis. Among newly diagnosed patients with moderate to severe asthma dosage were tapered in 5.5% (n=3) cases. Dosage consistency was well-maintained in 98.2% (n=155) among partial or uncontrolled asthmatics with moderate to severe asthma with exacerbation rate of 1.9% (n=3). Adverse events including infective pneumonitis and upper respiratory tract infection were transient with none requiring treatment withdrawal. Conclusion: Use of Airtec SF was safe and well-tolerated with a negligible rate of exacerbations in Indian population especially amongst poorly controlled asthma patients.

Pharmacologic reperfusion therapy with indigenous tenecteplase in 15,222 patients with ST elevation myocardial infarction - the Indian Registry.

To study the efficacy and safety of single intravenous bolus administration of indigenously developed tenecteplase (TNK-tPA) in the management of patients with ST-elevation myocardial infarction (STEMI) in clinical practice. Observational, prescription-event monitoring study. Data of 15,222 patients who had STEMI and received weight adjusted TNK injection was analyzed. Overall 95.43% patients had clinically successful thrombolysis (CST). In the different subgroups, hypertensives, diabetics, smokers and hyperlipidemic patients had CST rates comparable to the general patient data. CST rates were significantly lower in the elderly patients (>70 years; 92.11%; p < 0.0001), in patients with history of Ischemic Heart Disease (IHD, 93.86%; p = 0.0004) and in patients receiving delayed treatment (>6 h after onset of chest pain; 85.38%; p < 0.0001). CST was significantly higher in patients who received an early thrombolysis (<3 h after onset of chest pain; 96.54%; p = 0.006). Overall mortality was 1.69%, while it was significantly higher in the elderly (4.42%), patients with history of IHD (2.67%), females (2.93%) and in those who received delayed treatment (4.98%). The overall incidences of intracranial hemorrhage (ICH), bleeding excluding ICH, stroke and ventricular tachyarrhythmia were 0.39%, 2.01%, 0.16% and 2.35% respectively. Age >70 years, diabetes, hyperlipidemia and history of IHD were associated with a higher incidence of heart failure, myocardial re-infarction or ventricular tachyarrhythmias. However, incidence of ICH and bleeding other than ICH was comparable amongst all patient subgroups. This study confirms the safety and efficacy of indigenous tenecteplase in Indian patients with STEMI, including high risk subgroups. It also highlights the fact that delayed treatment denotes denial of benefits of pharmacologic reperfusion therapy.

Neuropsychiatric Events with Varenicline: a Modified Prescription-Event Monitoring Study in General Practice in England

Varenicline (Champix(®)), launched in the UK in December 2006, is indicated for the treatment of smoking cessation in adults (≥18years of age). In 2008, the Medicines and Healthcare products Regulatory Agency (MHRA) in the UK issued a warning suggesting that varenicline was associated with disparate neuropsychiatric symptoms, including depression, suicidal thoughts and behaviour. In response to this regulatory warning, the Drug Safety Research Unit conducted a modified prescription-event monitoring (M-PEM) study to monitor the safety of varenicline. The aim of this study was to estimate the incidence and examine the pattern of neuropsychiatric events reported to general practitioners (GPs) in England during the immediate postmarketing period for varenicline. A postmarketing surveillance study was conducted using the observational cohort technique of M-PEM. Patients were identified from dispensed prescriptions issued by primary care physicians between December 2006 and March 2007. Data on exposure, previous history of psychiatric illness and events reported during and after treatment were collected from questionnaires. In order to determine whether hazards for neuropsychiatric events of interest (depression, anxiety, aggression, suicidal ideation, non-fatal self-harm) were non-constant over time (which could indicate a possible association with the drug), the pattern of events was examined by plotting the smoothed hazard function estimate and then fitting a Weibull model. The Weibull model shape parameter (β) and 95% confidence interval were used as a test for a non-constant hazard function (where a value of 1 indicates a constant hazard over time). In addition to this analysis, the difference in incidence densities (IDs) between month 1 and months 2-3 were calculated and compared. The cohort comprised of 12,159 patients (median age 47years [interquartile range 19]; 56.9% [n=6924 female]). The number of events reported during treatment, reason for stopping, adverse drug reactions (ADRs), and the p-value for the Weibull shape parameter were as follows: depression (n=94; 42; 19; p=0.144); anxiety (n=94; 49; 9; p=0.009); aggression (n=7; 4; 2; p=0.465); suicidal ideation (n=8; 4; 1; p=0.989) and non-fatal self-harm (n=5; 1; 0; p=0.771). No differences in the IDs between months 1 and months 2-3 were found for any of the events. Whilst between 7 and 17% of neuropsychiatric events were attributed to the drug by GPs and approximately 20-50% were given as reasons for stopping, no signal was raised using the ID differences approach, and only anxiety was flagged as a potential signal for an ADR using the Weibull model. The signal for anxiety requires further evaluation to determine whether the drug plays a part in the development of anxiety or whether it is a withdrawal symptom caused by smoking cessation. Analysis methods will lack power when the numbers of events are low even when a large number of participants are included in the study.

Reasons for and Time to Discontinuation of Rimonabant Therapy

Background: Early treatment discontinuation will have a negative effect on a drug’s benefit-risk profile if discontinuation occurs earlier in time than the positive effects of treatment. This non-persistence of therapy has been associated with an increased risk of adverse health outcomes. Objective: The aim of this study was to explore relationships between patient characteristics and reasons for and time to discontinuation of rimonabant therapy, focusing on psychiatric events, because these were the main safety concerns for rimonabant. Methods: A modified prescription-event monitoring (M-PEM) study was conducted for rimonabant. Descriptive statistics were used to describe the patient population. Rate ratios with 95% confidence intervals (CIs) were calculated to explore associations between patient characteristics and selected categories of reasons for stopping (RfS). Median times to discontinuation were compared using the Mann-Whitney U test. Results: The cohort comprised 10 011 users of rimonabant, three of which were excluded from this analysis because of missing age or sex. A total of 7204 patients (72.0%) stopped using rimonabant (median observation time 323 days, interquartile range: 279–371 days). In addition, patients with a history of psychiatric illness were more likely to discontinue rimonabant therapy early for all reasons, but most pronounced due to psychiatric events (rate ratio 1.79; 95% CI 1.54, 2.09) than those without a history of psychiatric illness. In contrast, the rates of discontinuation due to lack of effectiveness, any clinical events and psychiatric events in patients with cardiovascular disease, type 2 diabetes mellitus, dyslipidaemia or hypertension tended to be lower (not all being significant) than those without. For patients who discontinued treatment due to lack of effectiveness, the median time to discontinuation was significantly shorter for patients with a history of psychiatric illness, compared with patients without a history of psychiatric illness (86 vs 97 days, p = 0.03). For patients discontinuing treatment due to psychiatric events, the difference in median time to discontinuation was also 11 days (64 vs 75 days, p = 0.38), although not statistically significant. For patients stopping due to any clinical event, median time to discontinuation was comparable for patients with and without a history of psychiatric illness (61 vs 63 days, p = 0.90). Conclusions: In this study, reasons for and time to discontinuation were associated with patient characteristics such as medical history. Patients discontinued treatment because of psychiatric events early after starting. In general, identification and characterization of early discontinuers, and increasing the understanding of reasons for stopping, may help healthcare professionals to develop targeted interventions to further improve treatment compliance, thereby optimizing treatment benefits and drug safety.

Modified Prescription-Event Monitoring Studies

Prescription-Event Monitoring (PEM) is a well established postmarketing surveillance technique designed to monitor the overall safety of newly marketed medicines as used in real-life clinical practice, usually in cohorts of at least 10 000 patients. At the Drug Safety Research Unit in the UK we are now moving towards a more targeted safety surveillance known as Modified PEM (M-PEM). These studies combine the advantages of conventional PEM studies (in monitoring general safety and identification of unexpected risks of a medicine) with that of a more targeted safety study that addresses specific questions (to better understand known or partially known risks with a medicine). Through the use of enhanced data collection questionnaires, M-PEM expands the range of applications of conventional PEM, which include more detailed characterization of real-life drug use, adherence to prescribing recommendations and targeted analysis of events requiring special monitoring by regulatory authorities. A particularly useful application is the evaluation of the safety of a medicine in special populations or subgroups (e.g. patients switching from another therapy or patients with a particular risk factor) or following important changes in the product's lifecycle (e.g. a licensing or formulation change). M-PEM studies therefore have an important contribution to make to pharmacovigilance and the risk management of medicines by providing valuable information on the use of new medications under real-life situations.

Paediatric post‐marketing pharmacovigilance: comparison of the adverse event profile of vigabatrin prescribed to children and adults

Post-marketing pharmacovigilance is a cornerstone of monitoring and evaluating the safety of medicines in children and adults. However the methods may require modification to detect paediatric signals. The aim of this study was to compare the adverse event (AE) profile of children and adults taking vigabatrin, using modified signal detection methods (SDMs). Data from the vigabatrin prescription-event monitoring study an observational cohort study (cohort 10,177 patients), stratified into one paediatric (0-17 years) and one adult (≥ 18 years) age group were examined using summary statistics for adverse drug reactions (ADRs), reasons for stopping and deaths. Incidence densities of AEs in children and adults in the first month of treatment were compared to months two to six to examine whether the AE rate was different in these two periods. AE rates in children were compared to those in adults (proportional reporting rates; PRRs and incidence rate ratios), to compare the AE profile between these age groups. Abnormal behaviour (PRR 5.3) and hyperactivity (PRR 4.5) were more frequently reported in children; confusion (PRR 25.0) and psychosis (PRR 12.5) more frequently in adults. In children 11.8% of ADRs were reported to the regulatory authority compared to 27.3% in adults. A higher proportion of children stopped treatment due to lack of effectiveness (57.7% vs. 47.5%). No deaths were attributed to vigabatrin. This study demonstrated that modified SDMs can be used to detect differences in the AE profiles between children and adults taking a medicinal product, and also to identify drug safety signals.

Safety profile of rofecoxib as used in general practice in England: results of a prescription-event monitoring study

Abstract Focal points

Hypoglycaemia with pioglitazone: analysis of data from the Prescription‐Event Monitoring study

To investigate the relationship between patients' characteristics, use of concomitant anti-diabetic therapies and the incidence of hypoglycaemia, an acute complication of the treatment of diabetes mellitus reported by general practitioners (GPs) during the first 9 months of the treatment with pioglitazone. We used data collected for the Prescription-Event Monitoring (PEM) study conducted by the Drug Safety Research Unit for patients prescribed pioglitazone between November 2000 and June 2001 by their GP in England. A Cox proportional-hazards regression model was used to assess this relationship. The original pioglitazone PEM cohort included 12,772 patients (mean age 60.9 years); 53% (6777) were male. A total of 77 patients experienced at least one hypoglycaemic episode (9.64 per 1000 patient-years). Women were estimated to have twice the hazard of having a hypoglycaemic event compared with men [hazard ratio (HR) 2.05; confidence interval (CI) 1.24, 3.41]. Patients taking combination therapy with sulfonylurea or insulin were estimated to have approximately three and four times the hazard of having an event compared with those who were not taking these adjunctive therapies [HR=3.11 (CI 1.64, 5.88); HR=4.15 (CI 1.74, 9.91), respectively]. Patients treated with adjunctive metformin were 25% less likely to experience hypoglycaemia than those who did not take concomitant metformin (HR=0.75; CI 0.44, 1.27). This study has shown that the treatment with pioglitazone was associated with a low incidence of hypoglycaemia. The factors possibly increasing the risk of hypoglycaemia were concomitant therapy with sulfonylurea or insulin and female gender.

Incidence of Venous Thromboembolism in Users of Strontium Ranelate

Strontium ranelate is indicated for the treatment of postmenopausal osteoporosis. An association between strontium ranelate and venous thromboembolism (VTE) was identified in an analysis of phase III clinical trials. To estimate the incidence of VTE in patients within the strontium ranelate (Protelos(R)) Prescription-Event Monitoring (PEM) study cohort during the first 12 months after starting treatment. Patients in this analysis were identified from dispensed prescriptions that had been issued by general practitioners (GPs) in England for strontium ranelate between October 2004 and January 2008. For each individual patient, a Green Form questionnaire was sent to their GP 12 months after the date of the first prescription issued for strontium ranelate, requesting information about the patient including start and stop dates of treatment (if stopped), age, sex, indication, any history of VTE events, reasons for stopping and whether the patient had any events since starting the drug. VTE was defined as reports of deep vein thrombosis (DVT) or pulmonary embolism (PE). The crude incidence of VTE was calculated for events that occurred during the first 12 months after starting treatment (plus 30 days after stopping), with 95% Poisson exact CIs for the whole cohort, and subsets defined by age and past history of VTE. The final analysis cohort consisted of 10 782 patients. Where specified, mean age was 73.3 years (SD 11.45) [n = 10 696]; 9833 (91.3%) were female and 934 (8.7%) were male. Where the history of VTE was specified, 233 patients (2.6%) had a history of VTE prior to starting. In the first 12-month period, there were 48 incident reports of VTE (DVT or PE) during treatment (or within 30 days of stopping) in the cohort, with 7696.89 years of exposure, giving a crude incidence rate of VTE of 6.24 cases (95% CI 4.60, 8.27) per 1000 patient-years exposed. This analysis has provided an estimate of the incidence of VTE in patients treated with strontium ranelate in the general practice setting. The rate is similar to estimates in populations of similar age and corresponds to the incidence found in patients from phase III clinical studies and observational cohort studies of strontium ranelate on this topic. The crude annual incidence rate of VTE in the PEM cohort is higher than the background annual incidence rate found in the UK population, but is similar to estimates in populations of similar age and populations receiving treatment for postmenopausal osteoporosis. Also, we acknowledge the potential for underestimating the incidence in this population. Nevertheless, this analysis contributes to the ongoing postmarketing safety assessment of this product.

Pregabalin as mono- or add-on therapy for patients with refractory chronic neuropathic pain: a post-marketing prescription-event monitoring study

This observational study examined the outcome of two different therapeutic strategies in the treatment of chronic neuropathic pain by including pregabalin (PGB) as mono- or add-on therapy in one of two treatment options. Patients with a pain score of > or =4, refractory to usual care for neuropathic pain for at least 6 months, were allocated consecutively to one of two treatment strategies according to the decision of the physician: complete switch to a flexible-dosage, monotherapeutic or add-on therapy with pregabalin (PGB group), or change established doses and combinations of pre-existing mono- or combination therapy without pregabalin (non-PGB group). After 4 weeks (primary endpoint) a significant improvement in pain reduction was documented in both intention-to treat (ITT) analysis (PGB group, n = 85: mean pain score reduction of 3.53, SD 2.03, p < 0.001; non-PGB group, n = 102; mean pain score reduction of 2.83, SD 2.23, p < 0.001) and per-protocol (PP) analysis (PGB group, n = 79: mean pain score reduction 3.53 vs. 2.83, p < 0.05; non-PGB group, n = 81; 3.5 vs. 2.9, p < 0.05) compared to baseline. Comparison of the results observed in the two groups shows that patients in the PGB group achieved significantly greater pain reduction. These results demonstrate that PGB administered twice daily is superior to treatment regimes without PGB in reducing pain and pain-related interference in quality of life.

Drug Utilization of Intrinsa® (Testosterone Patch) in England

Intrinsa is a transdermal testosterone patch that is indicated for use in hypoactive sexual desire disorder (HSDD) in women who have undergone bilateral oophorectomy and hysterectomy (surgically-induced menopause) receiving concomitant oestrogen therapy. To describe the utilization characteristics of the patients prescribed testosterone patch (Intrinsa) based on an interim analysis of an ongoing Prescription-Event Monitoring study in England, and to assess, where possible, if the product is being used within the licensed therapeutic indication. In this interim analysis, patients were identified from dispensed prescriptions that had been issued by general practitioners (GPs) for Intrinsa from March 2007. 'Green form' questionnaires were sent to GPs 6 months following the date of the first prescription for Intrinsa for each individual patient, requesting information including age, sex, start and stop dates of treatment (if stopped), prescribing indication and reasons for stopping. Additional questions were asked regarding the patient's menopausal status and use of concomitant oestrogen therapy. The interim cohort consisted of 756 patients. The majority of patients were reported to be female (746 [98.7%]) with a median (interquartile range) age of 50 years (44-55 years). The most commonly reported indication was the licensed indication of HSDD in 580 patients (76.7%). Just under one-half of the patients (n = 364 [48.1%]) were reported to have been hysterectomized and bilaterally oophorectomized (surgically-induced menopause) prior to starting Intrinsa; 127 patients (16.8%) were naturally menopausal. For 222 patients (29.4%) the GP specified that the patient was not using concomitant oestrogen therapy. Overall, only 219 patients (29.0%) in the cohort were being prescribed Intrinsa according to the manufacturer's recommendations. This study has highlighted that some clinicians are prescribing this product outside the recommended terms of the licence, with less than 30% of patients receiving Intrinsa according to prescribing guidelines. All events experienced by these patients will be analysed to detect any possible adverse events from using Intrinsa outside of the licensed therapeutic indication. The findings support the ongoing postmarketing risk management of the product.

The safety profile of tadalafil as prescribed in general practice in England: results from a prescription‐event monitoring study involving 16 129 patients

To examine the safety of tadalafil as used in general practice in England, and to compare the mortality rate due to ischaemic heart disease (IHD) in tadalafil users with that in the male population in England. Patients in this observational cohort study were identified from dispensed prescriptions for tadalafil issued by general practitioners (GPs) from February 2003 to November 2004. Demographic and outcome data (clinical events) were requested from patients' GPs using a postal questionnaire. A standardized mortality ratio (SMR) was calculated using indirect standardization for deaths from IHD in the cohort (where age was known) over a 1-year observation period compared to that in the English male population (2003). A sensitivity analysis was carried out to investigate the effects of missing data for age and cause of death. Clinical information was obtained for 16 129 patients (median age 60 years, interquartile range 52-67); the age was not specified for 3212 (19.9%) patients. At least a third of the patients had diabetes mellitus and 29% had hypertension. Comparison of the mortality rate due to IHD for the patients of known age with that in the English male population provided an SMR of 0.57 (95% confidence interval 0.38-0.83) indicating fewer observed deaths in the cohort than expected. The results of the sensitivity analyses investigating the effect of missing data for age and cause of death produced similar SMR estimates. One confirmed case of non-arteritic anterior ischaemic optic neuropathy (NAION) was reported during tadalafil therapy in a patient with other risk factors for this condition. The results from this prescription-event monitoring study suggest that tadalafil is generally well tolerated when used in general practice in England. The most frequently reported adverse clinical events were in keeping with clinical trial data and include headache, dyspepsia and back pain. There was no evidence of a greater mortality rate due to IHD in the tadalafil cohort than in the general male population. However, these results are limited by the use of an external comparator group and might be explained by a 'healthy cohort effect'. One event of NAION was reported, and although a causal relationship was not established it indicates that NAION occurs rarely in patients prescribed tadalafil.

Hypoglycaemia with Oral Antidiabetic Drugs

Hypoglycaemia is an acute complication associated with intensive treatment of patients with diabetes mellitus. This complication poses a major challenge in diabetes management. Furthermore, severe hypoglycaemia may be life threatening. Although hypoglycaemia is more often associated with insulin treatment, oral hypoglycaemic agents have the potential to trigger hypoglycaemia. The aim of this study was to quantify the incidence of hypoglycaemic events and to describe the pattern of these incident events during the first 9 months of treatment with four oral antidiabetic drugs, rosiglitazone, pioglitazone, nateglinide and repaglinide, prescribed in general practice in England. We used data collected for prescription-event monitoring (PEM) studies of rosiglitazone, pioglitazone, nateglinide and repaglinide. PEM is an observational, non-interventional, incept cohort study. Observation time for each patient and incidence rate (IR) per 1000 patient-years of treatment for hypoglycaemia was calculated for each drug cohort. Smoothed hazard estimates were plotted over time. Case/non-case analysis was performed to describe and compare patients who had at least one hypoglycaemic event in the first 9 months of treatment with those who did not. The total number of patients included in the analysis was 14,373, 12,768, 4,549 and 5,727 in rosiglitazone, pioglitazone, nateglinide and repaglinide cohorts, respectively. From these, 276 patients experienced at least one episode of hypoglycaemia. The IR was between 50% and 100% higher in patients receiving treatment with meglitinides compared with those treated with the thiazolidinediones (TZDs) [IR = 9.94, 9.64, 15.71 and 20.32 per 1,000 patient-years for rosiglitazone, pioglitazone, nateglinide and repaglinide, respectively]. The plot of the hazard function and the estimated shape parameter from the Weibull regression model showed that pioglitazone, nateglinide and repaglinide had non-constant (decreasing) hazards over time, whereas the hazard for rosiglitazone-treated patients was approximately constant over time. Nateglinide and repaglinide had similar shape hazard function, indicating a significantly higher number of hypoglycaemic episodes shortly after starting treatment. For women treated with TZDs, hypoglycaemia was reported more frequently than for men. This analysis shows that the frequency of reported hypoglycaemia within the study cohorts was relatively low. The rates of hypoglycaemia were not equal between drug classes. Treatment with nateglinide or repaglinide was characterized by a higher incidence of hypoglycaemia at the beginning of treatment. Further investigation is necessary to assess whether women treated with TZDs are more prone to hypoglycaemia than men. Findings from this study should be taken into account with other clinical and pharmacoepidemiological studies.

Hypoglycaemia with Pioglitazone: Analysis of data from the Prescription-Event Monitoring (PEM) study

Aims and objectives To investigate the relationship between patients’ characteristics, use of concomitant anti-diabetic therapies and the incidence of hypoglycaemia, an acute complication of the treatment of diabetes mellitus reported by general practitioners (GPs) during the first 9 months of the treatment with pioglitazone. Methods We used data collected for the Prescription-Event Monitoring (PEM) study conducted by the Drug Safety Research Unit for patients prescribed pioglitazone between November 2000 and June 2001 by their GP in England. A Cox proportional-hazards regression model was used to assess this relationship. Results The original pioglitazone PEM cohort included 12 772 patients (mean age 60.9 years); 53% (6777) were male. A total of 77 patients experienced at least one hypoglycaemic episode (9.64 per 1000 patient-years). Women were estimated to have twice the hazard of having a hypoglycaemic event compared with men [hazard ratio (HR) 2.05; confidence interval (CI) 1.24, 3.41]. Patients taking combination therapy with sulfonylurea or insulin were estimated to have approximately three and four times the hazard of having an event compared with those who were not taking these adjunctive therapies [HR = 3.11 (CI 1.64, 5.88); HR = 4.15 (CI 1.74, 9.91), respectively]. Patients treated with adjunctive metformin were 25% less likely to experience hypoglycaemia than those who did not take concomitant metformin (HR = 0.75; CI 0.44, 1.27). Conclusions This study has shown that the treatment with pioglitazone was associated with a low incidence of hypoglycaemia. The factors possibly increasing the risk of hypoglycaemia were concomitant therapy with sulfonylurea or insulin and female gender.

The Use of Lumiracoxib in General Practice in England: Results of a Modified Prescription-Event Monitoring study

The Use of Lumiracoxib in General Practice in England: Results of a Modified Prescription-Event Monitoring study

The Safety Profiles of Orlistat and Sibutramine: Results of Prescription‐Event Monitoring Studies in England

Observational cohort studies were conducted using prescription-event monitoring (PEM) to examine the safety profiles of the anti-obesity agents orlistat and sibutramine. Adverse events reported as case reports were also evaluated to determine whether these events were also identified by PEM. Patients were identified from dispensed prescriptions written by general practitioners (GPs) in England for orlistat or sibutramine. Patient demographic and clinical event information, including reasons for stopping and adverse drug reactions, were requested on questionnaires posted to GPs at least 6 months after the first prescription for individual patients. Event incidence densities (IDs) (number of first reports of event/1000 patient-months treatment) were calculated for month 1 (ID(1)) and months 2-3 (ID(2-3)). Published case reports were identified by searching Medline and Embase. The cohorts comprised 16,021 and 12,336 patients prescribed orlistat and sibutramine, respectively. Both cohorts had a median age of 45 years, and approximately 80% were female. The most common reason for stopping orlistat within 3 months was diarrhea (332 patients; 2.1% cohort), and for stopping sibutramine it was hypertension (203 patients; 1.6%). Clinical events significantly associated with taking orlistat were mainly gastrointestinal and those for sibutramine included central nervous system effects, nausea/vomiting, palpitation, and sweating. We identified 8 published case reports for orlistat and 10 for sibutramine that had equivalent or similar events assessed as causally related in the PEM studies. The PEM studies highlighted different adverse event profiles for orlistat and sibutramine that were consistent with their distinct pharmacological mechanisms and other published information.