Cancer pain management

American Journal of Pharmaceutical Education, Summer 1998 by Skaer, Tracy L

Adverse effects associate with NSAIAs include. GI bleeding and/or ulceration, tinnitus, skin rash, dizziness, blurred vision, renal damage, and cross allergenicity (especially with the propionic acid derivatives)(21,24,27). NSAIAs are contraindicated in patients with active peptic ulcer disease, and should be used cautiously in patients with previous history of NSAIA-induced gastritis. NSAIA-induced side effects including GI ulceration, impaired renal function, hypersensitivity, and prolonged bleeding time are of increased concern in the elderly. GI side effects can be minimized by avoiding long-term therapy or the addition of misoprostil in patients requiring extended therapy or are at increased risk of toxicity (i.e., elderly, history of GI ulceration, or cigarette smoking)(10,20). Narcotic Analgesics

Narcotic analgesics are recommended for patients suffering from moderate to excruciating pain (pain score of 3 to 5 on a scale of 0 to 5). Table III outlines the most commonly used narcotic analgesics and their relative equianalgesic doses(6,10,18,28,29).

Codeine and Hydrocodeinone

The addition of codeine to either aspirin or acetaminophen may effectively control mild to discomforting pain (pain score of 1 or 2 on a scale of 0 to 5)(630). Distressing pain (pain score of 3 on a scale of 0 to 5) often requires a more potent narcotic such as hydrocodone in combination with aspirin or acetaminophen. Care must be taken not to exceed four to six grams of acetaminophen per day. However. the potential for aspirin or acetaminophen toxicity and the dose-related side effects of these agents limit their use to patients with pain scores of 1 to 3 only(6). New products containing hydrocodone 1 Omg plus acetaminophen 650mg, and hydrocodone 7.Smg plus ibuprofen 200mg are now available for pain management.

Morphine

The majority of patients with advanced cancer have pain described as intense or excruciating (rated as 4 or 5 on a scale of 0 to 5), and will require more potent narcotics, best administered in pure form. This avoids limitations in narcotic dosing because of dose-related toxicity from a combination component (i.e.. aspirin, acetaminophen, ibuprofen). Morphine, oxycodone. hydromorphone, methadone, and transdermal fentanyl are commonly prescribed for patients with moderate to severe cancer pain(6).

Morphine is both safe and effective when administered by the oral, subcutaneous, rectal, continual intravenous infusion, patient-controlled intermittent intravenous or subcutaneous, epidural, or intrathecal route(28,31-36). The oral route of administration is preferred, provides relatively predictable serum levels, and has a longer duration of action than intravenous therapy(33). Oral morphine SR products are especially useful for their convenient ATC dosing (usually given every 8 to 12 hours), consistent analgesia, and often times fewer adverse reactions (e.g., nausea, vomiting) relative to oral morphine IR and other analgesic products(37). It is recommended that patients taking morphine SR orally for cancer pain also have a supply of morphine IR available in the event of breakthrough pain(6,33). Morphine SR doses can be further titrated based on the amount of morphine IR utilized for periods of breakthrough pain (Table IV).