The prescribing of methadone and other opioids to addicts: national survey of GPs in England and Wales

Abstract

Background: GPs occupy a pivotal position in relation to providing services to opiate misusers in the UK, and this is now cited to support initiatives in other countries.

Aims: To investigate GP involvement in the management of opiate misusers; and to examine the nature of this prescribing of methadone and other opioids.

Design: GP data collected via self-completion postal questionnaire from a 10% random sample of the 30 000 GPs across England and Wales. Patient prescription data obtained on opiate misusers treated during the preceding 4 weeks.

Setting: Primary healthcare practice in England and Wales in mid-2001.

Method: A questionnaire was mailed to a random 10% sample of GPs stratified by number of partners in the practice, with three follow-up mailshots. Data on drugs prescribed by these practitioners were also studied, including drug prescribed, form, dose and dispensing arrangements.

Results: The response rate was 66%. Opiate misusers had been seen by 51% of GPs in the preceding 4 weeks (mean of 4.1 such patients), of whom 50% had prescribed opiate-substitution drugs. This provided a study sample of 1482 opiate misusers to whom GPs were prescribing methadone (86.7%), dihydrocodeine (8.5%) or buprenorphine (4.4%). Of 1292 methadone prescriptions, mean daily dose was 36.9 mg - 47.9% being for 30 mg or less. Daily interval dispensing was stipulated by 44.6%, while 42.9% permitted weekly take-away supply.

Conclusions: In 2001 nearly three times as many GPs were seeing opiate misusers than was the case in 1985. Half were prescribing substitute-opiate drugs such as methadone (to an estimated 30 000 patients). However, there are grounds for concern about the quality of this prescribing. Most doses were too low to constitute optimal methadone maintenance; widespread disregard of the availability of supervised or interval dispensing increases the risks of diversion to the blackmarket and deaths from methadone overdose. Increased quantity of care has been achieved. Increased quality is now required.

Figure 1

National GP survey: samples and subsamples.

Figure 2

Methadone prescriptions: distribution of daily dose prescribed by GPs in England and Wales, 2001. Eighty-eight per cent were for a multiple of 5 mg. (Three prescriptions for daily doses >100 mg not displayed: 170, 255 and 305 mg.)

Figure 3

Methadone prescriptions: distribution of dispensing arrangements (seven pick-ups per week = daily collection, etc). (Two prescriptions for a single monthly pick-up, and three for pick-up twice a day are not shown.)