People who use drugs are at risk of getting infected with human immunodeficiency virus (HIV) and of transmitting the infection to other drug users via needle-syringe sharing or to their sex partners through unsafe sex. Injecting drug users can act as a bridge to transmit HIV to others with whom they have sexual contacts. According to the Integrated Biological and Behavioral Surveillance (IBBS) report 2011, 76% of injecting drug users (IDUs) in Kathmandu Valley consistently used condoms with female sex workers, while 40% used condoms consistently with non-regular sex partners and only 9% used condoms consistently with regular female sex partners in the past year . Numerous studies have found IDUs to be disproportionately likely to be involved in unsafe sex practices [2, 3]. Sex workers (male and female), who offer sex in exchange for money or drugs, are at high risk for HIV infection and can spread the virus to a large number of people. In addition, sexual contact between IDUs and non-injectors may also contribute to an increased incidence of HIV infection. Furthermore, HIV transmission to children by drug-injecting mothers (‘vertical transmission’) or by non-injecting mothers in partnership with IDUs is pervasive. As a result of high-risk sexual behaviour, HIV is also a risk among drug abusers who do not inject drugs.
Until the 1990s, injecting drug use was rare in Nepal. With the introduction of pharmaceutical drugs such as buprenorphine, benzodiazepines, chlorpromazine and dextropropoxyphene, a transition took place, away from smoking or chasing heroin and towards injecting drug mixtures, mainly of buprenorphine mixed with benzodiazepines and chlorpromazine, as well as other antihistamines—the so-called South Asian cocktail. Polydrug use appeared to be the norm (ranging from alcohol to heroin), and transition from non-injecting to injecting behaviour appeared to be linked to the need for choosing the most cost-effective route of administration .
As per the study conducted by the Central Bureau of Statistic (CBS) of Nepal, more than 46,310 people are using illicit, ‘hard’ drugs such as opiates, cocaine or amphetamines in Nepal . Most of them are male (92.8%); only 7.2% are women. A major share of this number, i.e. 61.4%, is constituted by injecting drug users. It is estimated that in Nepal, 70,256 people are living with HIV . A substantial proportion of IDUs are HIV-infected. However, in the metropolis region of Kathmandu, the prevalence of HIV infections among IDUs has decreased from 51.7% in 2005 to 20.7% in 2009 . According to the IBBS 2011 report, HIV prevalence was found in 16.3% of IDUs who had been injecting drugs for more than 5 years, while no HIV infections were found among those who had injected for less than 1 year .
The impact of many types of psychoactive substances, including alcohol, and regardless of the fact whether they are injected or not is risky to the extent that they are dis-inhibitors and affect the individual's ability to make decisions about safe sexual behaviour. In this context, the non-governmental organization ‘Recovering Nepal’ has found, according to its study from 2009, that IDUs are using multiple drugs as a mixture of injectable substances in order to achieve a stronger effect . This is also supported by the IBBS 2011 report which states that IDUs in Kathmandu Valley mostly used a combination of drugs. In fact, about 89% of the IDUs used different combinations of drugs . According to Larance and colleagues, buprenorphine has reportedly emerged as the favoured drug of injection among IDUs . Also, in India, an increase in the consumption of prescription opioids such as buprenorphine, codeine and dextropropoxyphene among drug users has been observed in the past decade . This so-called cocktail use behaviour has created health, social, economic and legal hazards to IDUs.
The coverage of opioid substitution treatment (OST) in Nepal is comparatively low, and high-risk injecting and sexual behaviour among IDUs continues. The financing of OST is largely provided by external donors, and donations have become scarce with the current global economic problems .
This study was conducted in order to understand the current situation of illegal drug use with a special focus on concurrent injection of a mixture of opioids, benzodiazepines and antihistamines in Nepal and to gain knowledge on the use of such ‘drug cocktails’ and its hazards in IDUs. In particular, this study aimed at identifying possible differences between drug users with and without concurrent consumption of opioids, benzodiazepines and/or antihistamines with respect to their living situation, health status, drug use history, different types of combinations of drugs, risk behaviour, causes and motives of consumption as well as the association of drug use and risk behaviour with HIV status.