Dependence and withdrawal
Many people are known to develop tolerance to the effects of benzodiazepines and gain little therapeutic benefit from chronic consumption. It has also been estimated that 10–30% of chronic benzodiazepine users are physically dependent on them and 50% of all users suffer withdrawal symptoms63.
Factors potentially associated with an increased risk of developing dependency include short duration of action, long-term use, high dose, high potency, alcoholism and other drug dependency, personality disorders and use without medical supervision. The BNF notes that lorazepam and oxazepam are associated with a greater risk of withdrawal symptoms11.
Withdrawal syndrome may be prolonged and may develop at any time up to 3 weeks after cessation of a long-acting benzodiazepine, or a few hours after cessation of a short-acting one. The syndrome includes anxiety, depression, nausea and perceptual changes. 'Rebound insomnia' also occurs, characterised by a worsening of the original insomnia symptoms. There are also problems of abuse with benzodiazepines as they enhance and often prolong the 'high' obtained from other drugs and alleviate their withdrawal effects6376.