Pain management in the addicted patient

Nurse Practitioner, Apr 2000 by Newshan, Gayle

An estimated 13.9 million Americans (6.4%) over age 12 are users of illicit drugs, and an estimated 11 million Americans (5 %) are heavy users of alcohol.1 The salient features of addiction are preoccupation with drug acquisition, compulsive drug use despite adverse consequences, and relapse.2 When patients with addictions also have pain, their treatment becomes a challenge to the health care provider.

Assessment

All patients should be routinely asked about their drug use, including crack/cocaine, heroin, alcohol, and marijuana. Despite problems of underreporting, self report is the best way to measure the duration, frequency, intensity, route of administration, and social context of drug use.3

Addiction Models

Modern society views addiction according to three models: the moral or adaptive model, the legal model, and the medical or disease model.4 According to the moral or adaptive model, the user is morally weak with no willpower. According to the legal model, drug use -is wrong because the user is doing something illegal and wrongful to society. Proponents of the medical or disease model view the user as suffering from a chronic illness, characterized by periods of relapse and remission, in which biologic, genetic, and environmental factors play a roles Adopting the last view may help eliminate bias and improve health care.

Myths and Misconceptions

"The pain is not real; the patient just wants to get high. " Pain is subjective; there is no blood test or scan that proves that pain is real. Differences in pain perception, pain intensity, and interference of pain in daily life do not exist when comparing chemically dependent and non-chemically dependent persons with human immunodeficiency virus or acquired immunodeficiency syndrome (AIDS).6,7,8 Drug users and nondrug users feel pain equally. Consequently, drug users should be evaluated and treated for pain. The challenge for clinicians is to determine when abuse is occurring. Evidence of abuse and relapse are found in Table 1.

"Giving drug users opiates will make them more addicted. " Relapse is part of addiction. The majority of patients with an addiction will relapse within 1 year following treatment? The health care provider should not consider relapse a personal affront, nor is fear of relapse a sufficient reason to withhold pain medication.

The relapse rate due to prescribed opiates is unknown. Although it is impossible to predict which patient will relapse, three high-risk situations are associated with relapse occurrence (see Table 2).10,11 Additional relapse triggers include having a large amount of free time, having money, and not participating in self help groups such as Narcotics Anonymous.12 Interventions for abuse behaviors are listed in Table 3.

"Because drug users are addicted, nothing's going to help their pain. " Do persons with a history of addiction require higher doses of analgesics? Few studies address this question. One study found that chemically dependent persons with AIDS did not require significantly higher or different opiate doses when compared with non-chemically dependent persons with AIDS and that pain relief was readily achieved.12 Poorly relieved pain in chemically dependent patients may be caused by undermedication.8

"If the patient is on methadone, he does not need opiates for pain. " Methadone patients feel pain and will require short-acting opiates for acute pain control in addition to their usual methadone dose.

Special Pharmacologic Considerations

If the methadone-maintained patient is started on rifampin (Rimactane) or phenytoin (Dilantin), the methadone dose may need to be increased or split because these drugs increase the metabolism of methadone.

Some addiction experts consider exposure to syringes or inhaled drugs to be a trigger for relapse.l3 Therefore, clinicians should avoid prescribing parenteral opiates or intranasal analgesics for chemically dependent patients when possible. Alternate administration routes, including oral, rectal, and topical, should be considered.

For chronic pain, long-acting opiates are preferable to short-acting opiates. The euphoria that may occur with short-acting opiates can trigger relapse and abuse. Long-acting preparations such as the fentanyl patch (Duragesic) or sustained release morphine (MS Contin, Oramorph) cause less euphoria while providing steady state blood levels. These long-acting preparations may be abused less. Long-acting preparations also have a low street value.

Active Drug User Treatment Issues

When possible, clinicians should use nonpharmacologic therapy such as physical therapy, acupuncture, heat, and relaxation training with active drug users. The clinician should also encourage patients to participate in a drug rehabilitation program.

Prescribing opiates to an active user of illicit drugs may place the provider at risk of legal sanctions. The clinician should clearly document the reason for prescribing opiates (pain control). Opiates should be discontinued when the clinical problem has resolved. An interdisciplinary approach can also be helpful.