Misuse of antimicrobials is increasing resistance to the point where the drugs may soon be ineffective, according to a report by the World Health Organisation. Misuse can arise through under- or over-use, it points out.
"Overcoming antimicrobial resistance," WHO's annual report on infectious diseases, says that antimicrobials are under-used in underdeveloped countries because people cannot afford to buy complete courses or they use counterfeit black market products, while, in wealthier countries, doctors are too eager to prescribe, leading to over-use.
Although the pharmaceutical industry is developing new versions of old drugs, few new classes of antibiotics have been discovered.
"If we fail to make full and proper use of medicines discovered in our lifetime, many of these drugs will slip through our grasp. Indeed, if we fail to make rapid progress during this decade, it may become very difficult and expensive - if not impossible - to do so later," says Dr Rosamund Williams (head of WHO's drug resistance team).
The most effective strategy against microbial resistance is to get it right first time and defeat resistance before it starts, says WHO. The drugs of today could continue to be effective if they were used more wisely and, where appropriate, more widely, the report adds.
If a serious effort is not made, antibiotic resistance will "send the world back to a pre-antibiotic age" it warns.