The perfect analgesic doesn’t exist yet, but . . .

CEBU CITY – The bottom-line objective in treating acute pain lies not only in effectively reducing the degree of pain by also in protecting the patient from further harm the medication may cause.

This was shared by Dr. Robert Levine, clinical associate professor of the Department of Orthopedic Surgery of Wayne State University School of Medicine in Detroit, Michigan, USA, during his brief lecture to the media at the Marriott Hotel here recently.

According to Levine, the treatment of pain requires a balancing of the beneficial effects against potential side-effects. As Hippocrates admonished, doctors, as they control the pain, should assure patients of a continued active and productive lifestyle.

Levine added that the perfect analgesic should be effective, long-acting, has a rapid onset of action, and causes no or minimal side-effects.

The primary medications for acute pain control include opiods like morphine, tramadol, non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, and selective cyclooxygenase-2 inhibitors (Coxibs) like rofecoxib.

Although most analgesics have proven to be effective, chronic use of most of them poses serious side-effects. "Studies have shown that even one of these medications caused more than 30 percent of the patients to discontinue therapy due to nausea, vomiting and dizziness," said Levine.

Other potential side-effects of pain medication, according to Levine, include central nervous system depression and dependency and the ever notorious gastrointestinal bleeding that can happen with long-term treatment.

The principal action of most analgesic is the same – to inhibit two cyclooxygenase (COX) enzymes: COX-1 and COX-2. COX-1 is the enzyme that protects the lining of the stomach, while COX-2 is involved with pain and inflammation.

When talking about rofecoxib, Levine cited the single-dose study by Malmstrom et al in 1999 which compared the efficacy of rofecoxib, celecoxib, ibuprofen and placebo in the management of pain following the extraction of two or more third molars.

In this study, ibuprofen acted rapidly in 24 minutes, and its effect lasted for almost nine hours. Celecoxib, on the other hand, provided pain relief only in 60 minutes and lasted only about five hours.

Rofecoxib had an onset of action of 30 minutes and a duration of action of more than 24 hours. The study showed that rofecoxib was both rapid-acting and long-acting.

Rofecoxib is the only Coxib approved by the US Food and Drug Administration and the Philippine Bureau of Food and Drugs (BFAD) for acute pain.

It is an effective analgesic that helps avoid many of the problems caused by other pain relievers. According to Levine, not only is rofecoxib effective and well-tolerated in the treatment of pain, but when used pre-emptively (prior to a surgical procedure/ pre-operative), the medicine is useful in lessening post-operative pain.

"The perfect analgesic does not exist yet, but rofecoxib definitely brings us one step closer," Levine said.

Rofecoxib is a product of Merck & Co. Inc., which operates in many countries as Merck Sharp & Dohme (MSD). It is currently approved in the Philippines for the acute and chronic treatment of the signs and symptoms of osteoarthritis, relief of pain and primary dysmenorrhea.