Assessment of abuse potential of benzodiazepines from a prescription database using 'doctor shopping' as an indicator.

BACKGROUND: Benzodiazepines are widely used for different purposes because of their pharmacological properties, but their abuse potential may represent a limitation to their use. Data suggest that this abuse potential may vary between products and available dosages. Doctor shopping (the simultaneous use of several physicians by a patient) is one of the most important ways in which prescription drugs, in particular benzodiazepines, are diverted. OBJECTIVE: To assess the potential for abuse of several benzodiazepines using doctor shopping in a French administrative area as a proxy for abuse. METHODS: All prescriptions reimbursed during the year 2003 in Haute-Garonne, France (one million inhabitants) for benzodiazepines that were available in ambulatory care through community pharmacies as solid oral forms were extracted from a reimbursement database. The benzodiazepines were alprazolam (0.25 mg, 0.50 mg), bromazepam 6 mg, clonazepam 2 mg, clorazepate (5 mg, 10 mg, 50 mg), diazepam (1 mg, 5 mg, 10 mg), flunitrazepam 1 mg, lorazepam (1 mg, 2.5 mg) and tetrazepam 50 mg. For each patient, the quantities prescribed, dispensed and obtained by doctor shopping (i.e. overlap between prescriptions from different prescribers) were computed. Benzodiazepines were compared using their 'doctor shopping indicator' (DSI, the percentage of each drug obtained through doctor shopping among the total reimbursed quantity). RESULTS: About 128 000 patients received at least one benzodiazepine during the year. Four groups of benzodiazepines were identified according to their abuse potential: very high abuse potential (flunitrazepam, DSI = 42.8%); high abuse potential (diazepam 10 mg, DSI = 3.2%; clorazepate 50 mg, DSI = 2.7%); intermediate abuse potential (alprazolam 0.50 mg, bromazepam, clonazepam, DSI ranging from 1.8% to 1.9%); and low abuse potential (other benzodiazepines and dosages, DSI ranging from 0.3% to 1.1%). CONCLUSION: The DSI can be used to assess the relative abuse liability of benzodiazepines and to detect signals of new patterns of abuse in settings where centralized records of prescription or deliveries are available for the great majority of patients.

[A pilot study in general practice: pressure to prescribe]. / Pression de prescription: étude pilote en médecine générale.

Among the irrational factors involved in medical prescribing, few studies have investigated the problem of the 'pressure to prescribe'. The aim of the present work was to quantify this 'pressure to prescribe' and to investigate some potential predisposing factors. Each instance of a patient's behaviour suggesting 'pressure to prescribe' was registered for 599 outpatient general-practice clinics. 'Pressure to prescribe' was defined as each clear request by a patient that counteracted the diagnostic and/or therapeutic strategy of physicians. The study included 246 men and 356 women (mean age: 45.4 years). 'Pressure to prescribe' was found in 142 patients, i.e. 23.7% (95% confidence interval [CI]: 20.7-27.4%). Among patients aged >18 years, the percentage increased: 27.0% (CI 95%: 23.0-31.4%), i.e. 122 of 452 patients. 'Pressure to prescribe' was first observed with requests for drugs (17.3%), biological tests (2.5%), sick-leave from work (2.09%), radiological procedures (1.1%), medical certificates (1.0%), physiotherapy (0.8%), and referral to a medical specialist (0.3%). The drugs most often associated with 'pressure to prescribe' were analgesic (27.6%), nonsteroidal plus steroidal anti-inflammatory (17.1%), gastroenterological (16.2%), anti-infectious (14.3%) drugs followed by vitamins plus antiasthenic (11.4%), antiseptic (10.5%), nasal decongestant (9.5%), 'vasodilatory' plus 'veinotonic' (8.6%) drugs. Pressure to prescribe neuropsychiatric drugs involved only 7.5% of requests. Two predisposing factors were identified: age (with an increased 'pressure to prescribe' for older people) and, less importantly, female gender (women tended to exert more 'pressure to prescribe' than men). Analysis of 'pressure to prescribe' is an important topic in the area of Social Pharmacology.