Managing Pain Medication in the Outpatient Wound Clinic

  Treatment of pain may soon become more challenging within outpatient wound clinics. Abuse, misuse, and diversion have led the FDA to consider reclassifying hydrocodone combinations, traditionally the “workhorses of pain management,” as Schedule II drugs. Previously referred to as triplicate, Schedule II drugs are recognized for their high potential for abuse, which may lead to severe psychological or physical dependence (see sidebar). Currently among Schedule III drugs, which are defined as only having a “potential” for abuse, a change to Schedule II for hydrocodone combinations would require more stringent prescription considerations. Many physicians do not feel comfortable prescribing controlled medications such as morphine, hydromorphone, and fentanyl for numerous reasons. As a result, they have either not gone through the process of ordering Schedule II prescriptions or they have ordered them and not used them often or with confidence. Additionally, some pain-management specialists refuse to see patients who live with chronic wounds. Many patients face challenges in simply being referred to specialists due to such circumstances as living in a geographical area with limited access and/or long waiting times for appointments. Making matters more difficult, the typical patient requiring a pain specialist isn’t generally ambulatory or healthy, and asking him/her to visit yet another healthcare provider is frequently a burden.   Regardless of the FDA’s ultimate decision on hydrocodone (as well as additional changes that could occur in the future), understanding the options available to treat those patients who visit the wound clinic is vital. This article will help wound care providers establish effective drug regimens for their patients when considering the potential for effectiveness as well as dangerous adverse events such as dependency and drug interactions.

Acknowledging Drug Dangers, Misconceptions

  First, it is important to note that drug tolerance (a decreased effectiveness of a medication over time) should not be confused with addiction. Some prominent warning signs of addiction (eg, hoarding, increased requests for medications, and moaning) can also be reactions to pseudoaddiction (inadequate pain treatment resulting in traits similar to those of addiction). It can be very difficult to spot the difference, but an abundance of literature exists on this subject and should be consulted. Long-term management of pain may need to play into the wound care provider’s thoughts when conducting initial patient assessments. Some individuals may return frequently with significant pain. Also, where pain resolution is immediately experienced, say, with a foot wound, this may lead the patient to walk more than is ideal for wound healing and result in clinical and painful setbacks to be addressed. As such, providers must take additional time to educate their patients about their medications, including how they work and what the side effects could be, to document the treatment and pain-management plan, and to provide the necessary prescriptions each month. Many experts also recommend that a written contract between the patient and provider that details the expectations and goals of treatment be drawn up and consulted. This approach adds to the provider/patient relationship and helps ensure that pain is being addressed safely. What follows is a review of pain management modalities based on philosophies borrowed from the fields of internal medicine, geriatric care, and hospice that can and have been integrated within the wound clinic. With a focus on medications, particularly opioids, this discussion does not include other viable options that wound care providers can consider for helping their patients manage pain, such as physical therapy, acupuncture, massage therapy, and psychological therapy. Note that pain may be treated more aggressively and be desired in a hospice situation that is appropriate in a wound clinic.

Pharmacological Options

  Most physicians are comfortable with prescribing neuropathic agents, NSAIDS, and acetaminophen. Many also use tramadol, anxiolytics, topical agents, and hydrocodone or codeine. But there is a general reluctance to prescribe other opioids. A commonly repeated phrase is that “stronger” opioids are being considered when the appropriate descriptor is “more potent.”   Remember: Morphine and hydrocodone have similar potency. Codeine is ineffective in a substantial group of patients due to its metabolism and is generally not well tolerated.     • Acetaminophen: appropriate for mild pain and fever; 24-hour dose limits to 4,000 mg (3,000 mg in the elderly; 2,000 mg with liver disease patients).     • NSAIDs: ibuprofen, naproxen; limit use with gastrointestinal and renal effects.     • Steroids: multiple side effects; delay wound healing; must be tapered and used sparingly.     • Neuropathic pain agents: (antidepressants): duloxetine, amitriptyline; neuroleptics: gabapentin, pregabalin.     • Opioids: most commonly hydrocodone, codeine, morphine, hydromorphone, oxycodone, and fentanyl.     • Others: tramadol;* muscle relaxants; anxiolytics; topical capsaicin; or lidocaine.     *Lowers seizure threshold, interacts with antidepressants, and has a narrow therapeutic window.

Opioids

  Opioids are discussed in terms of their relationship to morphine. Morphine IV is equal to one-third of the oral dose. Oral hydromorphone is about five times as potent as oral morphine. A 25 mcg/hr fentanyl patch is about as much as 50 mg of morphine spaced out over 24 hours. Calculating a patient’s morphine equivalent daily dose (MEDD) over 24 hours allows a prescriber to adjust doses and switch to alternative medications. There are multiple different tables (available on the web and in various publications) to use to help providers calculate equivalent doses. It is important to remember the concept of incomplete cross-tolerance, a physiological response to a medication as a result of tolerance to a pharmacologically similar drug, prior to a medication change. Also remember that neuropathic pain agents may potentiate the effect of opioids, so a lower dose may be necessary.

Starting A Regimen

  There are multiple issues to consider prior to prescribing pain medication. The first (or primary) determination is choosing the medication to be used. Secondary to this decision is determining how to manage the risks involved. Primary questions to consider in selecting a drug include: 1) Where is the pain? This is important: The wound care provider is not responsible for treating chronic back pain for a wound on the foot. 2) What type of pain is present? 3) Is it neuropathic or nociceptive? 4) What are the patient’s goals for pain management? Complete pain relief may have more side effects, and many patients will desire pain reduction to tolerable levels rather than have more side effects. 5) Does the patient have any allergies or previous response to medications that should guide the drug selection? 6) Are there comorbidities that would guide the medication choice? With experience, these questions are easily answered and an appropriate medication can be chosen without much delay.   Secondary questions that help assess whether or not the risk of opioids will be well managed include: 1) Is the patient receiving pain medications from any other provider? If yes, consider referring the patient back to the treating physician or call the treating physician to coordinate care. If no, let the patient know that by asking for pain medications he/she must agree not to attempt to get additional pain medications elsewhere. 2) Does the patient or anyone in his/her family/household have a history of addiction to alcohol, tobacco, pain medications, or illegal drugs? 3) Is there a risk of diversion? 4) Who will protect and administer the medications? Consider making these particulars part of the patient-provider contract to outline expectations and responsibilities. A sample contract by the American Academy of Pain Management is available online (www.naddi.org/aws/NADDI/asset_manager/get_file/32898/opioidagreements.pdf).   Though the FDA hadn’t reached a final decision on hydrocodone combinations as of press time for Today’s Wound Clinic, wound care providers may want to consider ordering prescription pads for Schedule II drugs and attending relatable continuing education in order to be prepared. The following patient example may also give appropriate guidance:

Patient Care Scenario

  A 62-year-old male living with diabetes and a large plantar wound is experiencing “sharp pain with every step and when sleeping at night.” He also complains of chronic “fire” to bilateral feet that has responded well to gabapentin. He is taking hydrocodone/acetaminophen (APAP) 10/325 mg and over the past month averages 12 pills per day, but still can’t sleep at night because of the pain. The patient is “in pain all of the time” and the hydrocodone only “helps for about one hour after each dose.”   Dose escalation is not possible due to risk of acetaminophen toxicity. A call to the primary care provider is made, and she asks that the “pain be taken care of while the wound is being treated.” She reassures the patient has no problems with abuse or addiction, which is confirmed by the patient, who also has no renal insufficiency or medication allergies. A pain contract is completed. The average intake of hydrocodone is 120 mg in 24 hours. That is equal to about 120 mg of morphine (MEDD = 120). With incomplete cross-tolerance, 60 mg of morphine would be a good start in a long-acting formulation for chronic pain. It isn’t clear how incomplete cross-tolerance will work in this patient, so prn doses of morphine, immediate release, will need to be available to the patient. In addition to educating the patient about constipation and other potential short-term side effects, an appropriate starting order would read: “morphine sulfate controlled release 30 mg PO q 12 hrs scheduled and morphine IR 5 mg PO q 2 hrs prn pain.” Two separate prescriptions would be prepared and the total number of pills to be dispensed would be written numerically and longhand. A copy of the prescriptions would go to the patient’s chart.   The patient returns the following week and has used an average of three prn doses each day for the past 48 hours. No changes are needed.   Questions that may be raised:     1) What if the patient returns and reports using 10 prn doses every day? The MEDD (24-hour dose) is “60 mg of morphine sulfate controlled release + 50 mg prn = 110 mg morphine in 24 hrs.” One option would be to change the morphine sulfate controlled release to “30 mg PO q 8 hrs” and continue the prn dose as previously ordered. Alternatively, the prn dose can be modified to “q 1 hr” or “10 mg q 2 hrs.” New prescriptions would need to be given to the patient with copies made for the clinic chart.     2) What if the patient can’t swallow pills well? Controlled-release morphine sulfate cannot be crushed or split (or it becomes immediate release), so an option would be to use a fentanyl patch. (This should never be the initial opioid a patient uses; this patient has already been on hydrocodone.) Remembering the MEDD (120 mg) and adjustments for incomplete cross-tolerance (about 50%), the appropriate fentanyl patch to start would be a 25 mcg/hr patch. These are distributed in boxes of 10 patches to be changed every 72 hours for a 30-day supply.     3) What if the patient complains of itching? Add an antihistamine for the first week. Nausea? Prochlorperazine or metoclopramide for the first week and after any dosage increase. Rash? Switch to a different opioid.

Moving Past The Pain

  Pain among wound clinic patients should decrease as the wound improves, and the patient should start to decrease his/her requests for opioids. Many patients experience more pain at night, so consider stopping the morning dose of extended-release medication to taper. This allows patients to sleep without waking for prn doses and enables them to use only what they require during the day. If you find the patient’s wound is improving but medication doses remain the same or increase, reassess risk factors for addiction or diversion. Review the type of pain and see if there is a neuropathic component that may respond to gabapentin, pregabalin, or antidepressants. Discuss the possibility of pseudoaddiction or addiction and tolerance with the patient. Ask about anxiety and a fear of pain. Reassure that you are trying to balance the risks and benefits of medications. Reassess the wound for any hidden problems such as underlying osteomyelitis or infection. Michelle Cunningham, MD, is board-certified in internal medicine, geriatrics, and hospice and palliative care. She currently practices hospice, geriatrics, and wound care in the Houston, TX, region.

References

1. Differential diagnosis: Nociceptive and neuropathic pain. Am J Manag Care. 2006;12(9 Suppl):S256-62.