cocaine guidance - Royal College of General Practitioners

21Appendix 3Appendix 3PrescribingPrescribed medication should never be used in isolation from a whole package of care, including relapse prevention.In light of the results of trials on a large number of drugs, it would seem reasonable to conclude that drug therapy isonly effective for the most part in treating individual symptoms such as depression or insomnia (short-term only) aftercrack or other stimulant use has ceased. There is no substitute medication, although many have been tried, and caremust be taken not to attempt pharmacological treatment where there is little or no evidence base for such an intervention.Benzodiazepines (e.g. diazepam): Can be used tohelp the ‘come-down’ from the agitated state that canresult from a binge, to relax and to help sleep. They areuseful in these circumstances but should only be usedin low doses (less than 30 mg) and short-term (less than2 weeks). Remember they have their own addictivepotential.Disulfiram (Antabuse ® ): There is some evidence thatdisulfiram reduces use by decreasing the pleasureassociated with cocaine use. 28 When drinking is integralto how the user manages their cocaine/crack use,deterring alcohol use through disulfiram can also interferewith cocaine/crack use patterns, but should not be usedin primary care.Other sedatives: Phenothiazines, such aschlorpromazine or haloperidol, are used for the samepurpose but are best not be used in primary care.These should not be used if there is cardiovasculardamage e.g. atrial fibrillationAntidepressants: such as selective serotonin reuptakeinhibitors e.g. fluoxetine, and lofepramine are importantonly if underlying depression is confirmed and crack andother stimulant use stops. SSRIs should be used withcaution if cocaine use continues, because of the rareoccurrence of the ‘serotonergic syndrome’, which ischaracterised by changes in autonomic, neuromotor andcognitive-behavioural function triggered by increasedserotonergic stimulation. 26 Work has taken placecomparing imipramine and placebo in users comingoff cocaine and has found no difference. Desipraminetreatment of cocaine dependence in methadonemaintainedpatients showed no effect. 27 Reboxetine,a selective inhibitor of noradrenalin re-uptake, is alsobeing tried.Propranolol (beta blockers): has been shown in somestudies to reduce anxiety and relapse rate. It can be usedduring withdrawal. Contraindicated in asthmatics, as itcan cause bronchial spasmAmphetamines: A recent pilot study in Australia hasshown that there may be a role for dexamphetamineprescription in refractory cocaine users. This is supportedby a two small-scale studies in USA showing that longactingamphetamine may be useful in cocaine-usingmethadone patients. 29 The evidence as yet does notjustify wider adoption of this treatment. Other work usingdexamphetamine in primary users showed it was noteffective and it should not be used in primary care. 30Methylphenidate (Ritalin ® ) may reduce craving and iscurrently in trials. Two new dopamine-reuptake inhibitorsare also being explored, but have never been used inprimary care. Trials are also planned for selegiline, whichreduces dopamine metabolism.Review of other medication triedA review of the evidence shows little or no support forthe clinical use of dopamine agonists, mazindol, phenytoin,nimodipine, amantadine, bromocriptine, carbamazepine,buproprion (Zyban ® ) and lithium in the treatment ofcocaine dependence. 31