Opioid analgesics are useful agents for treating pain of various etiologies; however, adverse effects are potential limitations to their use. Strategies to minimize adverse effects of opioids include dose reduction, symptomatic management, opioid rotation, and changing the route of administration. Nausea occurs in approximately 25 percent of patients; prophylactic measures may not be required. Patients who do develop nausea will require antiemetic treatment with an antipsychotic, prokinetic agent, or serotonin antagonist. Understanding the mechanism for opioid-induced nausea will aid in the selection of appropriate agents. Constipation is considered an expected side effect with chronic opioid use. Physicians should minimize the development of constipation using prophylactic measures. Monotherapy with stool softeners often is not effective; a stool softener combined with a stimulant laxative is preferred. Sedation and cognitive changes occur with initiation of therapy or dose escalation. Underlying disease states or other centrally acting medications often will compound the opioid's adverse effects. Minimizing unnecessary medications and judicious use of stimulants and antipsychotics are used to manage the central nervous system side effects. Pruritus may develop, but it is generally not considered an allergic reaction. Antihistamines are the preferred management option should pharmacotherapy treatment be required.