Non-narcotic analgesics
Nonsteroidal anti-inflammatory drugs (NSAIDs) - aspirin and other
NSAIDs-are the mainstay of initial drug treatment for mild pain. They
should be taken on a prescribed schedule. Because patients are accustomed
to taking aspirin sporadically for headaches and other minor pains, it
must be emphasized that, for cancer pain control, the medication is to be
taken regularly, whether pain is present or not, at the prescribed time.
A wide variety of NSAIDs are commercially available. (See Table X -
Nonsteroidal Anti-Inflammatory Agents, pages__.) All have antipyretic and
anti-inflammatory activity, and all except the non-acetylated salicylates,
e.g., choline magnesium trisalicylate (Trilisate), interfere with platelet
aggregation and therefore prolong bleeding time. This effect on platelets
limits the use of all NSAIDs in thrombocytopenic patients. The antipyretic
effect limits the use of these drugs in patients who are neutropenic
because an infection could be masked. Other side effects of NSAIDs include
gastrointestinal irritation and renal insufficiency.
Aspirin and other NSAIDs are frequently combined in fixed doses with weak
opiates. Combining NSAIDs with opiates is a rational approach to pain
management because the two groups of drugs have different mechanisms of
action. Studies have shown that the augmented effect is more than merely
the sum of the analgesic potencies of the two drugs. CAUTION: When
increasing the dose of these combination drugs, be careful to remember the
presence of the aspirin or other NSAID because toxic doses of this
component of the drug can unwittingly occur and cause severe gastric
irritation and/or bleeding.
NSAIDs are particularly useful for treating pain from bone metastases.
When pain from bone metastasis is moderate to severe, it often is
necessary to use an NSAID/opiate combination. Some soft tissue metastases
have surrounding inflammation that also responds well to NSAIDs.
Acetaminophen has analgesic and antipyretic but weak anti-inflammatory
activity. It has no adverse effect on platelets and does not irritate the
gastrointestinal tract. Hepatic toxicity occurs when high doses are used
and in patients with a history of alcohol abuse. Acetaminophen is also
frequently used in combination with weak opiates. When increasing the dose
of drugs, i.e., increasing the number of tablets per dose combining
opiates with acetaminophen, one must be careful not to unwittingly reach a
toxic dose of acetaminophen.
