A/HRC/10/44 page 18 Rapporteur also refers to other United Nations human rights mechanisms that have expressed concerns about the severity of penalties relating to narcotics offences.41 56. Some of the problems faced by drug users in the criminal justice system with regard to ill-treatment are examined below. 1. Lack of access to medical treatment and drug substitutes during detention 57. Drug users are particularly vulnerable when deprived of their liberty. One of the questions in this context concerns withdrawal symptoms and to what extent they may qualify as torture or ill-treatment. There can be no doubt that withdrawal symptoms can cause severe pain and suffering if not alleviated by appropriate medical treatment, and the potential for abuse of withdrawal symptoms, in particular in custody situations, is evident. In a 2003 case, without specifically stating that the woman died from withdrawal, the European Court of Human Rights found a violation of the prohibition of inhuman or degrading treatment or punishment based on “the responsibility owed by prison authorities to provide the requisite medical care for detained persons”.42 Moreover, if withdrawal symptoms are used for any of the purposes cited in definition of torture enshrined in article 1 of the Convention against Torture, this might amount to torture. 58. Also at later stages of detention, access of detainees to medical treatment, including access to opioid substitution therapy, is often severely restricted. Whereas the World Health Organization (WHO), the United Nations Office on Drugs and Crime and UNAIDS all concur that the therapy is the most effective intervention available for the treatment of opioid dependence and a critical component of efforts to prevent the spread of HIV among injecting drug users,43 that it considerably reduces mortality and epidemics among drug users and that it improves uptake and adherence to antiretroviral treatment for HIV-positive opiate drug users,44 41 A/HRC/4/40/Add.3, paras. 85-88; E/CN.4/1999/68/Add.2, paras. 817, 18 and 83; CCPR/CO/83/MUS, paras. 15 and 85-88; A/55/40, paras. 422-451; CCPR/CO/70/PER, para. 13. 42 McGlinchey and others v. The United Kingdom (Application No. 50390/99), judgement of 29 April 2003, para. 57). 43 See also WHO/UNODC/UNAIDS: Interventions to address HIV in prisons - drug dependence treatments. Evidence for action technical papers, 2007, at www.unodc.org/documents/hiv-aids/ EVIDENCE%20FOR%20ACTION%202007%20drug_treatment.pdf and WHO, UNODC, UNAIDS, “Substitution maintenance therapy in the management of opioid dependence and HIV/AIDS prevention: Position paper” (2004). 44 WHO background note: Access to Controlled Medications Programme, September 2008.