QUESTION: In my unit, we occasionally care for patients being treated for HIV or AIDS who are in pain. How can we ease their pain without creating drug interaction problems?
ANSWER: Patients with HIV or AIDS may have pain related to their disease, their treatments, or coexisting health problems. Start by performing a complete pain assessment and medication history, including use of prescription drugs, over-the-counter products, and herbal supplements. Also take a history of substance abuse and assess risk factors for opioid misuse if appropriate.
Many patients with HIV or AIDS experience nociceptive pain, which can be somatic or visceral. Somatic pain may be cutaneous, as with Kaposi's sarcoma or oral cavity lesions; visceral pain may result from hollow organ distension, as in pancreatitis, or from tumor expansion.
In addition, many patients experience neuropathic pain. Peripheral neuropathy is a common neurologic complication of HIV and AIDS infection; besides HIV itself, causes include opportunistic pathogens and certain drug therapies. Because the cause of neuropathic pain is often unclear, treatment is symptomatic. Drugs effective for this pain type include tricyclic antidepressants, such as nortriptyline, and anticonvulsants, such as lamotrigine (Lamictal). Shown to significantly reduce HIV neuropathic pain, lamotrigine isn't affected by protease inhibitors used to treat HIV infection.
Drugs commonly used to treat HIV infection interact with many drugs, including opioids. For example, protease inhibitors such as ritonavir and indinavir and the antifungal ketoconazole inhibit the cytochrome P450 3A4 enzyme system in the liver. This enzyme system metabolizes methadone, hydrocodone, fentanyl, and oxycodone. Drugs that inhibit this enzyme system can slow opioid metabolism, resulting in a higher peak effect, longer duration of action, and increased risk of adverse reactions to the opioid. If your patient is taking ritonavir or indinavir and needs an opioid to manage pain, start with a low opioid dose and titrate upward slowly as needed while monitoring his response.
Don't let concerns about addiction lead you to undertreat patients with a history of opioid abuse. With individualized treatment, these patients can safely take opioids for pain control. Frequently reassess the patient's pain level, adjusting your interventions to provide optimal pain management. Keep in mind that a patient who's opioid-tolerant may need higher doses to manage pain. A multidisciplinary team, including a mental health professional with expertise in addiction medicine, can help you set realistic therapy goals, deal with the issue of opioid tolerance, and prevent or minimize your patient's withdrawal symptoms.
With understanding and compassion, you can help keep a patient with HIV- or AIDS-related pain comfortable.
Joan D. Wentz is an assistant professor at Barnes-Jewish College of Nursing and Allied Health in St. Louis, Mo.
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