Responsible drug use (RDU) is a harm reduction strategy based on a belief that illegal recreational drug use can be responsible in terms of reduced or eliminated risk of negative impact on the lives of both the user and others.
Some critics believe that all illegal recreational use is inherently irresponsible, due to the unpredictable, unregulated nature of the drugs and the risks of addiction, infection, and other side effects. Nevertheless, harm reduction advocates claim that the user can be responsible by employing the same general principles applicable to the use of alcohol: avoiding hazardous situations, excessive doses, hazardous combinations of drugs, using the smallest dose necessary, avoiding injection, and not using drugs at the same time as activities such as driving, swimming, operating machinery, or other activities which are unsafe without a sober state.
Duncan and Gold argue that to use controlled and other drugs responsibly, a person must adhere to a list of principles. They argue that drug users must understand and educate themselves on the effects and legal status of the drug they are taking, measure accurate dosages and taking other precautions to reduce the risk of overdose, and chemically test all drugs they are using to determine their purity and strength. As well, they argue that drug users should avoid driving, operating heavy machinery, or otherwise being directly or indirectly responsible for the safety or care of another person while intoxicated. When taking hallucinogenic drugs, they suggest that a user have a trip sitter. They also propose some ethical guidelines, such as the statement that a person should never trick or persuade anyone to use a drug, allow drug use to overshadow other aspects of one's life, and being morally conscious of the source of the drugs that you are using.
Duncan and Gold suggested that responsible drug use involves responsibility in three areas: situational responsibilities, health responsibilities, and safety-related responsibilities. Among situational responsibilities they included concerns over the possible situations in which drugs might be used legally. This includes the avoidance of hazardous situations, not using when alone, nor using due to coercion or when the use of drugs itself is the sole reason for use. Health responsibilities include avoidance of excessive doses or hazardous combinations of drugs, awareness of possible health consequences of drug use, and not using a drug recreationally during periods of excessive stress. Safety-related responsibilities include using the smallest dose necessary to achieve the desired effects, using only in relaxed settings with supportive companions, avoiding the use of drugs by injection, and not using drugs while performing complex tasks or those where the drug might impair one's ability to function safely.
Responsible drug use is emphasized as a primary prevention technique in harm-reduction drug policies. Harm-reduction policies were popularized in the late 1980s although they began in the 1970s counter-culture where users were distributed cartoons explaining responsible drug use and consequences of irresponsible drug use.
If the drawbacks of recreational drug use outweigh the benefits, then it can be argued that it is inherently irresponsible. It is widely believed that drugs are used to escape reality,, although it is usually presumed that this is a negative thing, rather than discussed. Drug use and users are not always considered socially acceptable; they are sometimes marginalized socially and economically by the ignorant. It is argued that drugs affect work performance; however, drug testing should not be necessary if this is so, as a user's work performance would be observably deficient, and be grounds in itself for dismissal. In the case of discriminate use of amphetamines and similar drugs, physically work capacity actually increases. While some people may be able to use some drugs for many years without serious consequences, others may have an unexpected reaction to the drug, even on first use. While funds are diverted from drug research and testing to law enforcement, the reasons for these discrepancies, and therefore the means to remove or avoid harmful consequences remain elusive.
Some types of drugs are very addictive, and even moderate use may result in a strong physical need for an increased dosage; illegality makes this a supply problem, as the price of illegal drugs is artificially raised far above the production and transportation costs. Purity and potency of many drugs is difficult to assess as they are illegal, this may affect the ability to use them safely. Drug dosage is problematic while drugs are illegal and therefore unregulated. Profit motivation rewards illegal sellers adding a cutting agent to drugs, diluting them; when a user, expecting a low dose, procures 'uncut' drugs, an overdose can result. The morality of buying certain illegal drugs is also questioned given that the trade in cocaine, for instance, has been estimated to cause 20,000 deaths a year in Colombia alone. However the majority of deaths currently caused by the illegal drug trade can only take place in a situation in which the drugs are illegal. The illegality of drugs in itself may also cause social and economic consequences for those using them, and legal regulation of drug production and distribution would alleviate these and other dangers of illegal drug use.
Harm reduction as applied to drug use began as a philosophy in the 1980s aiming to minimize HIV transmission between intravenous drug users. It also focused on condom usage to prevent the transmission of HIV through sexual contact.
Harm reduction worked so effectively that researchers and community policy makers adapted the theory to other diseases to which drug users were susceptible, such as Hepatitis C.
Harm reduction seeks to minimize the harms that can occur through the use of various drugs, whether legal (e.g. alcohol and nicotine), or illegal (e.g. heroin and cocaine). For example, people who inject illicit drugs can minimize harm to both themselves and members of the community through proper injecting technique, using new needles and syringes each time, and through proper disposal of all injecting equipment.
Other harm reduction methods have been implemented with drugs such as crack cocaine. In some cities, peer health advocates (Weeks, 2006) have participated in passing out clean crack pipe mouthpiece tips to minimize the risk of Hepatitis A, B and C and HIV due to sharing pipes while lips and mouth contain open sores.
The responsible user therefore minimizes the spread of blood-borne viruses such as hepatitis C and HIV in the wider community.
The provision of safe injection sites operates under the premise of harm reduction by providing the injection drug user with a clean space and clean materials such as needles, sterile water, alcohol swabs, and other items used for safe injection.
Vancouver, British Columbia  opened a SiS called Insite in its poorest neighbourhood, the Downtown Eastside. Insite was opened in 2003 and has dramatically reduced many harms associated with injection drug use. The research arm of the site, run by The Centre of Excellence for HIV/AIDS has found that SiS leads to increases in people entering detox and addiction treatment without increasing drug-related crime. As well, it reduces the littering of drug paraphernalia (e.g., used needles) on the street and reduces the number of people injecting in public areas. The program is attracting the highest-risk users, which has led to less needle-sharing in the Downtown Eastside community, and in the 453 overdoses which occurred at the facility, health care staff have saved every person.
In the Netherlands, where drug use is considered a social and health-related issue and not a law-related one, the government has opened clinics where drug users may consume their substances in a safe, clean environment. Users are given access to clean needles and other paraphernalia, monitored by health officials and are given the ability to seek help from drug addiction.
Due to the project's initial success in reducing mortality ratios and viral spread amongst injection drug users, other projects have been started in Switzerland, Germany, Spain, Australia, Canada and Norway. France, Denmark and Portugal are also considering similar actions.