Letters

Long term use of hypnotics and anxiolytics May not result in increased tolerance

BMJ 1994; 309 doi: https://doi.org/10.1136/bmj.309.6956.742a (Published 17 September 1994) Cite this as: BMJ 1994;309:742
  1. K E Logan,
  2. S M Lawrie
  1. Professorial Unit, Royal Edinburgh Hospital, Edinburgh EH10 5HF
  2. Academic Department of Psychiatry, Royal Free Hospital, London NW3 2QG.

    EDITOR, — Both Neil Wright and colleagues1 and John W G Tiller2 question whether long term use of benzodiazepines is as bad as the media stereotype suggests. We provide evidence that long term prescription of this class of drugs does not necessarily result in increasing tolerance.

    Altogether 191 (3.9%) patients receiving computerised repeat prescriptions of hypnotic and anxiolytic drugs (British National Formulary class 4.1) were identified from a general practice with a list of 4857 patients in Haddington, Lothian region, in 1992. Primary care case notes for 181 of these patients were available for review. The mean age of these patients was 69 (range 4-93). They had received long term treatment (defined as a two month supply of tablets at least three times each year) for a mean of 5.6 years (range 1-41), but the first prescription had been a mean of 20 years before (range 2-41), indicating that many patients had received the drugs intermittently. Seventy patients had been changed from their original hypnotic or anxiolytic to another drug in the same class.

    There was little evidence of increasing tolerance as escalation of the dose was rare, having occurred in only 15 cases. In contrast, the dose had been reduced in 30 cases, and the remaining 136 patients had taken the same dose since the initial prescription. All doses conformed with the British National Formulary's guidelines.

    The reasons for starting the treatment were recorded in 57 cases: insomnia (17), neurological disease (for example, epilepsy) (16), anxiety state (13), bereavement (4), alcohol withdrawal (3), and others (4). Long term administration was inappropriate for some of these indications, notably bereavement and alcohol withdrawal, and may reflect problems with dependence. Hospital doctors were recorded as having initiated the prescription in only six cases. Wright and colleagues report that 45 (73%) of the patients in their study taking daytime benzodiazepines (anxiolytics) had had documented contact with a psychiatrist.1 In contrast, only 29 (16%) of the patients in our study, who were receiving hypnotics or anxiolytics, or both, had seen a psychiatrist. Twenty eight were receiving concurrent psychotropic drugs: antidepressants (24), antipsychotics (6), and lithium carbonate (3). Thus patients who receive hypnotics long term may be less likely to have seen a psychiatrist than those who receive anxiolytics, and their routine referral to psychiatrists could cause a substantial increase in psychiatric workload.

    Medical practitioners are generally advised not to prescribe benzodiazepines long term.3 As Tiller argues,2 however, doctors should remember the potential negative effects of not prescribing such drugs. Some patients are severely disabled by anxiety and insomnia and may treat themselves with potentially more harmful agents, including alcohol. The usual rationale for avoiding long term prescription is to avoid the risk of tolerance, necessitating steadily increasing doses, and dependence, manifest by discontinuation phenomena. However, the dose had been increased in only 8% of the patients in our study, and no more than 30-40% of long term users suffer withdrawal reactions.3 Medical conservatism may be as potent as media alarmism in denying some patients symptomatic relief with anxiolytics and hypnotics.

    References

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    Night time users ignored

    1. M King
    1. Professorial Unit, Royal Edinburgh Hospital, Edinburgh EH10 5HF
    2. Academic Department of Psychiatry, Royal Free Hospital, London NW3 2QG.

      EDITOR, — There is nothing new about Neil Wright and colleagues' finding that 0.5% of one general practice population were long term daytime users of benzodiazepines and that almost half expressed a desire to keep taking the drugs.1 The authors' conclusions (and those of John W G Tiller in his accompanying editorial2) were that prescribing of these drugs has declined and that the stereotype of dependent patients wishing to come off the drugs is false.

      Daytime use of benzodiazepines is only half the story; more than half of long term users in general practice take the drugs at night,3 and it is among these patients that reducing prescribing is hardest.4 In 1988 colleagues and I published the results of a similar study to that of Wright and colleagues,5 and, though we did not give separate figures for daytime use, they can be derived from the figures for patients taking diazepam and lorazepam. The calculated prevalence was 0.67% (95% confidence interval 0.43% to 0.98%). This confidence interval overlaps with that for Wright and colleagues' data, which, though not given in their paper, can be calculated as 0.38% to 0.62%. With regard to the views of long term users, at least four surveys since 1987 have reported that more than half of such users wanted to continue taking the drugs and did not see them as harmful.

      In the light of such extensive earlier work, conclusions such as “exhortations [to reduce prescribing of benzodiazepines] have worked” and “a community survey in this week's journal does not confirm earlier notions of long term use of benzodiazepines”2 seem uninformed.

      References

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