Pharmaceuticals are chemicals that are used because of their biological activity. They are often excreted unchanged and can reach the environment. Throughout developed countries, the pharmaceutical concentrations in the aquatic environment are in the same range (μg L-1 and below); however, it is not clear whether this holds for less-developed countries too. The health risks of active pharmaceutical ingredients (APIs) remain poorly understood. Although there are no known short-term effects on humans, long-term effects cannot be ruled out until there is more research. The significance of metabolites and transformation products resulting from the parent APIs is not yet known. Awareness of the presence of pharmaceuticals in the environment, coupled with some evidence of effects, suggests that precautionary management action to reduce the release of pharmaceuticals to the environment should be considered. As for effluent treatment, no technology works well for all compounds. Advanced effluent treatment is not sustainable because of energy consumption, efficiency, and efficacy. Therefore, its appropriateness must be assessed on a case-by-case basis. Increased handling and use measures at the source and better biodegradable pharmaceuticals are necessary in the long run for the new paradigm called "sustainable pharmacy." Copyright © 2010 by Annual Reviews. All rights reserved.