Codeine
Codeine is frequently prescribed in combination with acetaminophen in a product marketed as Tylenol #3 for mild-to-moderate pain. Because codeine is metabolized in the liver to morphine, it is contraindicated in patients with morphine allergy. Also, the clinician must be aware that codeine is ineffective in 7% to 10% of the population due to an enzyme deficiency.
Hydrocodone and oxycodone, which are often combined with acetaminophen and marketed respectively as Vicodin and Percocet, are two additional commonly used compounds in the oral treatment of moderate-to-severe pain. There are numerous preparations containing various strengths of both the opioid and acetaminophen components. Utilizing these medications as initial pain control in the ED can be beneficial, as therapy can be continued as an outpatient. Table 2 provides dosing and frequency information, but the clinician must also be aware of the total amount of acetaminophen administered, especially when being used in conjunction with other medications containing acetaminophen.
Tramadol
Tramadol (Ultram), another oral analgesic with opioid properties, affects several neurotransmitters and is less reliant on the opioid receptors compared to the opioid compounds described above. It is used to treat moderate-to-severe pain and can be considered another option along with codeine, hydrocodone, and oxycodone for oral pain control. Although the complete mechanism of action for tramadol is poorly understood, it appears to be effective in patients who do not respond well to pure opioids, and in patients with neuropathic pain or persistent pain of unclear etiology (eg, fibromyalgia).19 Because of its limited interaction with opioid receptors, tramadol has less potential for abuse and addiction than the opioids. It is also available in several combinations with acetaminophen or ibuprofen.
Conclusion
The ideal medication for treating pain in the ED is one that is effective, easy to administer, and has minimal adverse or residual effects. Generally, the least potent medication that will control pain should be chosen initially. When treating minor traumatic or musculoskeletal pain, initiating pain control with oral medication in the ED may provide patients with relief during imaging or splinting, and help control pain until they can fill outpatient prescriptions. All of the medications discussed in this article can be given in the oral form. However, IV usage may be appropriate when there is need for rapid onset of action, to titrate the medication, or for ease of administration in patients who are vomiting or unable to take anything orally.
When prescribing analgesics for pain control after discharge, the clinician must consider potential relative and absolute contraindications. For acetaminophen, liver toxicity is the major concern, and care must be taken not to exceed recommended daily dosing limits with the multitude of available products containing acetaminophen. Physicians should avoid recommending or prescribing acetaminophen to patients with liver disease (ie, cirrhosis) or habitual alcohol abuse.
Nonsteroidal anti-inflammatory drugs such as ibuprofen and naproxen carry the risk of renal damage, as well as concerns about antiplatelet activity. Because of the tendency for renal function to decline with age, caution must be exercised in using these compounds in older patients and those with preexisting renal dysfunction.
Opioid-containing medications are known for their potency in pain control, but also for their side effects. The most common side effect involves the GI tract, with nausea, vomiting, and constipation. The most dangerous side effect of opioids is respiratory depression; fortunately, this is rarely seen with therapeutic doses. However, somnolence and decreased coordination are significant concerns when prescribing opioids to elderly patients or those already at risk for falls.
There is no ideal single medication to treat all types of pain or situations. However, the choice of medication begins with a decision by the EP to treat pain. Utilizing a stepwise approach, oral medication will usually be effective for mild pain, but IV narcotics will probably be required for severe pain. Frequent reassessment of the patient is critically important for successful pain management in the ED.
Dr Byers is an emergency physician at the Presbyterian Medical Group, department of emergency medicine, Presbyterian Healthcare Services, Albuquerque, New Mexico. Dr Counselman is a distinguished professor of emergency medicine and chairman, department of emergency medicine, Eastern Virginia Medical School and Emergency Physicians of Tidewater, Norfolk, Virginia. He is also associate editor-in-chief of the Emergency Medicine editorial board.