Patients should remain under appropriate surveillance for resp depression. Resuscitation equipment & opioid antagonist should be readily available. Induction of muscle rigidity & non-epileptic myoclonic movements can occur. Bradycardia & cardiac arrest can occur if the patient has received insufficient amount of anticholinergic or when combined w/ non-vagolytic muscle relaxants. Appropriate measures to maintain stable arterial pressure should be taken. Avoid use of rapid bolus inj of opioids in patients w/ compromised intracerebral compliance. Patients on chronic opioid therapy or w/ a history of opioid abuse; uncontrolled hypothyroidism; pulmonary disease; decreased resp reserve; alcoholism. Co-administration w/ neuroleptics & drugs that affect the serotonergic neurotransmitter systems eg, SSRIs, SNRIs, MAOIs. Patients w/ COPD, decreased resp reserve & w/ potentially compromised respiration. Consider rapid discontinuation if serotonin syndrome is suspected. May impair ability to drive & use machines. Impaired hepatic or renal function. Not to be used during pregnancy. Breastfeeding is not recommended for 24 hr following administration. Childn <2 yr. Eldery & debilitated patients.