A New Option for Migraine Treatment on the Horizon

Millions of people who suffer from migraine headaches would literally stand in line for a freedom from their pain, especially if they would not have to endure adverse effects to get relief. The good news is that this option may soon be available. Researchers are testing a new drug called telcagepant that works differently than standard migraine medications.

The excruciating pain of a migraine comes in the form of an intense pulsing or throbbing pain localized to one area of the head. It is frequently accompanied by an extreme sensitivity to light and sound, as well as nausea and vomiting. Untreated attacks can last anywhere from 4 hours to several weeks.

Victims of migraines suffer from recurring attacks that are triggered various factors such as lack of food or sleep, exposure to light, or in women, hormonal irregularities. In fact, migraines are three times more common in women than in men. Experiencing anxiety, stress, or finally relaxing after undergoing stress may also prompt migraines. In the past, scientists have theorized that migraines were associated with the dilation and constriction of blood vessels within the head. Yet, many now believe that migraines are the result of inherited abnormalities in genes that control the activities of certain cell populations in the brain.

Migraines are commonly treated with drugs known as triptans like zolmitriptan (zomig). However, the use of these medications carries the risk of side effects such as dizziness, paresthesia (tingling or numbness of the skin), throat tightness, and chest discomfort. They are not recommended for use in patients who experience hemiplegic migraines (migraines that cause numbness on one side of the body), nor are they suitable for those who suffer from basilar-type migraines, which is an uncommon type of complicated migraine with symptoms that result from brainstem dysfunction. Additionally, triptans are not an appropriate therapy for patients with cardiovascular disease or high blood pressure, because they cause the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels (vasoconstriction).

The experimental drug telcagepant has a different method of action and has been shown to be as effective as triptans with fewer adverse effects, according to researchers. Telcagepant is from a different drug class known as calcitonin gene-related peptide (CGRP) antagonists. Because it is believed that levels of CGRP in the brain are elevated during a migraine, the CGRP adversary telcagepant may be effective against it. Another positive factor is that CGRP antagonists do not appear to cause narrowing of blood vessels, which means that may not carry any cardiovascular-related risks.

In the phase III study conducted by drug maker Merck & Co., 1,380 patients suffering from moderate or severe migraines were given either 150 milligrams or 300 milligrams of telcagepant, 5 milligrams zolmitriptan, or a placebo. Those patients who received the 300-milligram dose of telcagepant experienced the most freedom from pain at 27 percent, compared to only 10 percent of those taking the placebo, with pain relief experienced by 55 percent compared to 28 percent of those on placebo. In addition, absence of noise sensitivity was reported by 58 percent versus 37 percent and lack of light sensitivity was reported at 51 percent versus 29 percent, with no nausea experienced by 65 percent compared to 55 percent of the placebo patients.

Results for study participants taking telcagepant 300 milligrams and zolmitriptan 5 milligrams were found to be similarly effective in treating migraines, with both dosages proving more effective than telcagepant at 150 milligrams. Adverse effects were reported by 31 percent of participants who received telcagepant 150 milligrams compared to 32 percent taking placebo, with 37 percent of those taking telcagepant 300 milligrams experiencing side effects compared to 51 percent of those taking 5 milligrams of zolmitriptan.

Tony Ho, M.D., Merck Research Laboratories, acknowledged the need for further studies regarding this issue to determine the safety of telcagepant in patients with cardiovascular disease. He also said, "Additional studies are also necessary to assess the long-term efficacy and safety profile of telcagepant in patients treating more than one migraine attack."