Migraines quickly relieved with sumatriptan gel: experimental formulation.
Within 30 minutes of applying an experimental transdermal sumatriptan gel at the base of the neck, 93% of patients reported that they had either mild or no headache pain. "It's pretty amazing. It rivals injections but without the side effects," Dr Aung-Din said in an interview.
Results from the open-label trial are promising for patients who find injections and nasal sprays inconvenient or undesirable or whose first-line therapy is not available orally, he said.
Some of his patients now use the gel exclusively for treating migraine at a cost of about $15 per syringe. Dr. Aung-Din is conducting a double-blind, crossover, placebo-controlled study of the gel with a grant from AlgoRx Pharmaceuticals Inc
Dr Aung-Din treated 42 patients who had moderate to severe headache at his Sarasota, Fla., practice with 12.5 mg of transdermal sumatriptan in Lipoderm (0.1 mL of a formulation containing 125 mg/mL of extracted sumatriptan solubilized in Lipoderm through a proprietary method). The patients had migraines based on International Headache Society criteria, with a frequency of one to four attacks per week. Two patients presented twice during the study period, resulting in a total of 44 patient encounters. The gel was applied to the midposterior cervical area at the hairline using a calibrated 0.5-cc syringe and gently rubbed into the skin.
Headache relief was apparent on average within 5 minutes (range 1-12 minutes) of gel application. Headache response rates (mild or no headache) were 32% at 10 minutes and 93% at 30 minutes. Three patients with persistent moderate headache pain at 30 minutes responded after the transdermal sumatriptan was readministered.
Only three patients (7%) had headache recurrence within 24 hours of treatment. The low recurrence rate may be due to higher saturation of tissues involved in the migraine process (brain stem and cervical muscles) through local application of the triptan. Five patients (11%) had side effects: slight lightheadedness, dizziness, or throat/tongue tingling. None had chest tightness or chest pain.
The exact mechanism of action is unknown, but relaxation of cervical muscle tension often was the first sign of migraine relief, suggesting a possible peripheral deafferenting mechanism that aborts central migraine processes. The gel, which enters the neck muscles and skin where there are receptors for serotonin, probably reduces or shuts off discharges from the trigeminal nerve, which innervates the sinus cavities and blood vessels in the scalp and upper cervical nerves.
Also, absorption into the regional cerebral circulation is suggested by the presence of "typical" triptan side effects in some patients, he added.
The gel bypasses gastrointestional absorption, hepatic first-pass metabolism, and systemic circulation. Absorption of oral triptans can be delayed by the presence of food in the GI tract and by the migraine attack itself, which can slow GI transit. As much as 85% of a migraine medication can be lost to digestion.
Dr. Aung-Din conducted two previously reported open-label studies in which sumatriptan was found promising as a transdermal treatment when delivered as microemulsion in pluronic lecithin organogel and Lipoderm. The reformulated preparation using chemically extracted sumatriptan dissolved in Lipoderm appears to provide improved efficacy over the previous methods that used crushed tablets suspended in microemulsion, he said.
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|Title Annotation:||Pain Medicine|
|Author:||Norton, Patrice G.W.|
|Publication:||Clinical Psychiatry News|
|Date:||Nov 1, 2003|
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