Sibutramine usage in New Zealand: an analysis of prescription data by the Intensive Medicines Monitoring Programme

Intensive Monitoring Studies for Assessing Medicines: A Systematic Review

Introduction: Intensive monitoring (IM) is one of the methods of post-marketing active surveillance based upon event monitoring, which has received interest in the current medicines regulatory landscape. For a specific period of time, IM involves primary data collection and is actively focused on gathering longitudinal information, mainly safety, since the first day of drug use.

Objectives: To describe IM systems and studies' data published over 11-years period (2006–2016). Specifically, we reviewed study population/event surveillance, methodological approaches, limitations, and its applications in the real-world evidence generation data.

Methods: We completed a systematic search of MEDLINE and EMBASE to identify studies published from 2006 to 2016, that used IM methodology. We extracted data using a standardized form and results were analyzed descriptively. The methodological quality of selected studies was assessed using the modified Downs and Black checklist.

Results: From 1,400 screened citations, we identified 86 papers, corresponding to 69 different studies. Seventy percent of reviewed studies corresponded to established IM systems, of which, more than half were prescription event monitoring (PEM) and modified-PEM. Among non-established IM systems, vaccines were the most common studied drugs (n = 14). The median cohort size ranged from 488 (hospitals) to 10,479 (PEM) patients. Patients and caregivers were the event data source in 39.1% of studies. The mean overall quality score was similar between established and non-established IM.

Conclusions: Over the study period, IM studies were implemented in 26 countries with different maturity levels of post-marketing surveillance systems. We identified two major limitations: only 20% of studies were conducted at hospital-level, which is a matter of concern, insofar as healthcare systems are facing a lack of access to new medicines at ambulatory care level. Additionally, IM access to data of drug exposure cohorts, either at identification or at follow-up stages, could somehow constitute a barrier, given the complexity of managerial, linkable, and privacy data issues.

Fatal and non-fatal cardiovascular events in a general population prescribed sibutramine in New Zealand: a prospective cohort study

BACKGROUND

The cardiovascular safety of sibutramine is currently under review by medicines regulatory authorities worldwide after the SCOUT (Sibutramine Cardiovascular Outcome Trial) showed an increased risk of cardiovascular events in patients taking sibutramine. Further data regarding the cardiovascular safety of sibutramine in a general population are now required.

OBJECTIVE

To quantify the risk of fatal and non-fatal cardiovascular adverse events in a general population prescribed sibutramine in postmarketing use.

STUDY DESIGN

Observational prospective cohort study of patients dispensed sibutramine during a 3-year period (2001-4) and followed up for at least 1 year after their last prescription. The study included record-linkage to national mortality datasets to identify fatal events.

SETTING

Postmarketing 'real-life' use of sibutramine in a general population in New Zealand.

PATIENTS

All New Zealand patients dispensed a prescription for sibutramine in a 3-year period (for whom a National Health Identification number could be validated). 15 686 patients were included in the record linkage study for fatal events. A subgroup of 9471 patients was followed up by intensive methods for non-fatal events.

MAIN OUTCOME MEASURES

(i) Rate of death from all causes and from cardiovascular events; and (ii) rates of non-fatal cardiovascular adverse events.

RESULTS

Total exposure to sibutramine for 15 686 patients in the validated cohort was 5431 treatment-years. The rate of death from all causes in this cohort was 0.13 (95% CI 0.05, 0.27) per 100 treatment-years exposure. The rate of death from a cardiovascular event was 0.07 (95% CI 0.02, 0.19) per 100 treatment-years exposure. The most frequent non-fatal cardiovascular events in the intensively followed up cohort were hypertension, palpitations, hypotensive events and tachycardia.

CONCLUSIONS

Risk of death from a cardiovascular event in this general population of patients prescribed sibutramine was lower than has been reported in other overweight/obese populations. The results of this study suggest that further evaluation of the benefit-risk profile of sibutramine is now required.

The use of sibutramine in the management of obesity and related disorders: an update

Aims:

To review the major trials that evaluated the efficacy and safety of the use of sibutramine for weight loss and the impact of this agent on obesity-related disorders.

Methods and results:

The most important articles on sibutramine up to January 2009 were located by a PubMed and Medline search. Sibutramine reduces food intake and body weight more than placebo and has positive effects on the lipid profile (mainly triglycerides and high density lipoprotein cholesterol), glycemic control and inflammatory markers in studies for up to one year. Preliminary studies showed that sibutramine may also improve other obesity-associated disorders such as polycystic ovary syndrome, left ventricular hypertrophy, binge eating disorder and adolescent obesity. The high discontinuation rates and some safety issues mainly due to the increase in blood pressure and pulse rate have to be considered. Additionally, it has not yet been established that treatment with sibutramine will reduce cardiovascular events and total mortality.

Conclusions:

Sibutramine, in conjunction with lifestyle measures, is a useful drug for reducing body weight and improving associated cardiometabolic risk factors and obesity-related disorders. Studies of longer duration are required to determine the precise indications of the drug, to evaluate safety issues and to assess its efficacy on cardiovascular mortality.