These recommendations are in line with published reviews and guidelines on managing benzodiazepine dependence and are based on expert opinion and limited evidence [CSM, 1988; Lader and Russell, 1993; Mant and Walsh, 1997; Ashton, 2002b; Australian Government Department of Health and Ageing, 2004; Lingford-Hughes et al, 2004; Taylor et al, 2007; BNF 56, 2008; Lader et al, 2009].

• Although less well-studied, given that they work similarly, the same approach as for withdrawing benzodiazepines has been recommended for withdrawing z-drugs [Ashton, 2002c].
• These recommendations also apply to older people; they can stop benzodiazepines as successfully as younger people [Ashton, 2002b]. Benzodiazepine withdrawal is particularly important for older people as they are more prone to their adverse effects and have more to gain from benzodiazepine cessation, see Reasons for stopping.

Gradual withdrawal of benzodiazepines and z-drugs

• Although good quality evidence for this is lacking, withdrawing benzodiazepines gradually is recommended to allow a smooth, gradual fall in the level of drugs in the blood, thus minimizing withdrawal symptoms [Lingford-Hughes et al, 2004; Ashton, 2005; BNF 56, 2008; Lader et al, 2009].
• Abrupt drug withdrawal can produce confusion, toxic psychosis, convulsions, or a condition resembling delirium tremens [BNF 56, 2008; Lader et al, 2009]. This is more likely in people taking high doses, although seizures or psychosis may occur when other predisposing factors are also present [Schweizer and Rickels, 1998; Ashton, 2005].
• As the optimal speed or duration of dose reduction is unknown [Lingford-Hughes et al, 2004; Lader et al, 2009], drug withdrawal should be guided by individual choice and severity of withdrawal symptoms.
• Gradual drug withdrawal is also recommended for people dependent on z-drugs as the manufacturers of these drugs warn that abrupt termination of treatment can lead to withdrawal symptoms, particularly in people taking high doses [ABPI Medicines Compendium, 2008; ABPI Medicines Compendium, 2009a; ABPI Medicines Compendium, 2009b].

Switching to diazepam

• Despite the lack of good quality evidence, switching to diazepam is recommended for some people — particularly if they have difficulty withdrawing or if they are on short-acting, potent benzodiazepines [Ashton, 2002b; Ashton, 2005; BNF 56, 2008].
• Diazepam is preferred because:
• It possesses a long half-life (20–100 hours), thus avoiding sharp fluctuations in plasma level.
• It is available in a variety of strengths and formulations. This facilitates stepwise dose substitution from other benzodiazepines or z-drugs and allows for small incremental reductions in dosage (especially at low doses).
• The National Institute for Health and Clinical Excellence does not recommend the substitution of z-drugs for people who are being withdrawn from benzodiazepines as this is not supported by available evidence of reduced potential for dependency [NICE, 2004].