Background: Serotonin-1 5-hydroxytryptamine (5-HT 1) receptor agonists are first line agents for migraine headaches. Patients with refractory headaches may use supratherapeutic doses of these medications. Described is a case of ischemic colitis related to overuse of sumatriptan.Case: A 35-year-old woman presented with severe abdominal pain without diarrhea or hematochezia. For several days prior she had been self-treating a refractory migraine headache with frequent doses of sumatriptan. She is a nonsmoker and took no oral contraceptives or other serotonin agonists. A computed tomography scan of the abdomen revealed left-sided colitis. A colonoscopy with biopsy confirmed ischemic colitis and excluded inflammatory bowel disease (IBD).Discussion: Previously published case reports have suggested an association between 5-HT 1 receptor agonists and ischemic colitis. These reports have been dismissed because the patients were taking oral contraceptives, serotonin agonists, or had other comorbidities. This healthy patient lacked risk factors for ischemia, is the youngest to be reported, and is the first without hematochezia.Conclusion :

The effects of felodipine, a dihydropyridine vasodilator, were investigated in a canine model of hemorrhagic shock. Mongrel dogs were anesthetized with sodium pentobarbital and subjected to hemorrhagic shock by allowing the animals to bleed into a reservoir. After maintaining the hypotensive state (mean blood pressure: 40-60 mm Hg) for a period of 150 min, the blood was reinfused and the recovery of the various parameters were monitored for an additional 120 min. These studies were conducted in three different groups of dogs: A) controls, B) felodipine, 0.01 mumol/kg i.v., was administered before reinfusion of the blood and C) felodipine, 0.01 mumol/kg i.v., was administered prior to hemorrhage. In all the three groups, arterial blood pressure returned essentially to pre-hemorrhage levels following reinfusion; in the groups A and B, there was about 80% recovery of the cardiac output, whereas in the group C cardiac output returned completely to the basal values. During the hemorrhagic hypotension, renal and mesenteric blood flows fell to 10-40% of the basal values in all the three groups. In the control group A, there was only 40 to 45% recovery in the renal and mesenteric flows after reinfusion indicating sustained vasoconstriction in these vascular beds. Felodipine administration before reinfusion (group B), resulted in 70% to 90% recovery in the renal and mesenteric flows after reinfusion. In the group C (felodipine before hemorrhage) there was 85% recovery in the renal flow and 100% in the mesenteric blood flow after reinfusion. The observations made in this study suggest that felodipine, an arteriolar dilator, may be clinically useful in restoring organ blood flows which are seriously compromised during the hemorrhagic shock.