Effects of the anti-migraine drug sumatriptan on muscle energy metabolism:relationship to side-effects

Sumatriptan succinate (Imitrex) is a 5-HT(5-hydroxytryptamine) agonist used for relief of migraine symptoms. Some individuals experience short-lived s ide-effects, including heaviness of the limbs, chest heaviness and muscle a ches and pains. The effects of this drug on skeletal muscle energy metaboli sm were studied during short submaximal isometric exercises. We studied ATP flux from anaerobic glycolysis (An Gly), the creatine kinase reaction (CK) and oxidative phosphorylation (Ox Phos) using P-31 nuclear magnetic resona nce spectroscopy (P-31 MRS) kinetic data collected during exercise. It was found that side-effects induced acutely by injection of 6 mg sumatriptan su ccinate s.c. were associated with reduced oxygen storage in peripheral skel etal muscle 5-20 min after injection as demonstrated by a transient reducti on in mitochondrial function at end-exercise. These results suggest that mi ld vasoconstriction in peripheral skeletal muscle is associated with the ac tion of sumatriptan and is likely to be the source of the side-effects expe rienced by some users. Migraine with aura patients were more susceptible to this effect than migraine without aura patients.