Opioids are widely used drugs for treatment of pain and related disorders. Opiate addiction is a major public health concern in the United States causing significant increase in healthcare expenditure. They produce euphoria and sense of well-being which makes them addictive to some people. Used in higher doses they can lead to cardiac or respiratory compromise. They also impair cognition leading to impaired decision making. Opioids exert their effects by acting on three different types of receptors mu, delta, and kappa located on neuronal cell membranes causing inhibition of neurotransmitter release. Prolonged use of these drugs can lead to physical dependence causing withdrawal symptoms if a person stops using them. Commonly used medicati...