The availability of cheap antibiotics has saved many lives, but it has also created a severe public health problem. Patients and physicians may benefit in the short run by liberally prescribing and consuming antibiotics, but we would be better off if antibiotics were reserved for relatively serious infections. The diffusion of antibiotic-resistant bacteria into our environment is a predictable side effect of the widespread use of antibiotics - which some have described as a collective action problem. In contrast, using narcotics does not create a collective action problem since the costs and benefits are borne by the users themselves. We should call off the war on drugs. There is a stronger justification to regulate the use of antimicrobial drugs instead Although many argue that recreational drug use harms non-users, most of the harm associated with these drugs - such as theft and murder - is caused not by drug use, but rather by the enforcement of drug laws. These laws create the conditions for black markets to flourish, for violence to be used and police corruption to thrive. The evidence from the only country to decriminalise personal possession of all recreational drugs, Portugal, suggests that consumption has not significantly increased for most drugs, and has declined for some. We should call off the war on drugs and consider more humane and less intrusive alternatives for helping drug addicts. There is a stronger justification to regulate the use of antimicrobial drugs instead. Yet in many countries antibiotics are sold over-the-counter and dispensed without thought for the consequences. We should think hard about how to regulate them in a way that balances individual liberty and public health. One person using an appropriate course of antibiotics may recover from an infection and prevent himself from becoming a vector. But he also increases the risk of harm to himself and others by increasing the prevalence of antibiotic-resistant bacteria in his own body and the environment. Thus, Margaret Battin at the University of Utah and her colleagues conclude that the choice to consume antibiotics "is partly a problem of prudence, of considering apparent short-term benefits against unknown but serious risks for oneself now and oneself in the future; and it is also a collective action problem, because the resistance one engenders in one's own body may also affect others". In economic terms, the collective action problem stems from the fact that the price of antibiotics fails to include the social cost of resistance. This distortion is exacerbated by health care systems in which third-party payers - including governments and health insurance companies - blind physicians and patients to the full cost of treatment. What, then, should be done to minimise the collective harm associated with antibiotic use? Educating patients and doctors about the nature and risks of antibiotics can go some way to reducing careless consumption. We should also phase out the use of antibiotics in farm animals, and forbid factory farming more generally. This would help preserve the efficacy of existing antibiotics for human use and reduce the threat of zoonotic viral infections such as avian flu and swine flu. For antibiotics to remain effective, we may also need to incentivise pharmaceutical firms to conserve existing drugs and encourage developing nations to ban over-the-counter sales of antibiotics. Wealthier nations should share information and surveillance technology with developing nations to monitor outbreaks of resistant pathogens. Battin et al suggest that we should simply "add a fixed amount, say a US$1 surcharge to every course of a first generation antimicrobial, and a slightly larger surcharge - say, US$2 - to each second generation antimicrobial course. Funds generated could be used to support antimicrobial research by the government directly or through grants and contracts". Dr Jonny Anomaly is an ethicist from Duke University. This column is an abridged version of a recent article from the Journal of Medical Ethics .