Prolonged vasoconstriction due to ergotamine tartrate

Interactions between animal temperament and exposure to endophytic tall fescue: Effects on cell-mediated and humoral immunity in beef heifers

Two experiments (n=12 Angus heifers/experiment) investigated influences of animal temperament, as indicated by exit velocity (EV; determined at weaning) and consumption of toxic endophyte-infected tall fescue seed on peripheral lymphocyte production of interferon-γ. Heifers were selected from calves born on the University of Kentucky’s C. Oran Little Research Center. In experiment 1, calves were randomly selected from 50 heifers within a single calf crop. In experiment 2, calves with the 6 fastest and 6 slowest EV in the subsequent year’s calf crop were selected. In both experiments, heifers were assigned to either high or low EV treatments based on relative ranking, and endophyte treatments (toxic endophyte-infected, E+, or endophyte-free, E-, fescue seed) were balanced by body weight. Rations were restricted to 1.8 x NEm and common diet was top-dressed with fescue seed each morning. Experiment 1 had four phases (pre-endophyte treatment/thermoneutral, increased room temperature, increased room temperature/endophyte treatment, and post-endophyte/thermoneutral) and experiment 2 had two phases (increased room temperature/endophyte treatment and thermoneutral). During endophyte treatment phases, heifers were fed their respective treatment seed. During all other phases, all heifers received E- seed. In experiment 1, proportions of lymphocytes producing interferon-γ were decreased in E+ heifers during the heat/endophyte phase (P=0.03) whereas during the subsequent thermoneutral period this response was greater in high, compared with low, EV heifers on E- treatment, with no difference observed among E+ heifers (interaction P=0.08). Also during the recovery phase, average lymphocyte production of interferon-γ was higher in E+ heifers (P=0.01). Consistent with experiment 1 findings, during the recovery period of experiment 2, endophyte exposure increased the per cell production of interferon-γ (P<0.01). In this experiment, the difference was of sufficient magnitude to result in a concomitant increase (P=0.03) in total interferon-γ production during that period. These results indicate peripheral lymphocyte production of interferon-γ can be influenced by both EV and endophyte exposure following periods of increased ambient temperature humidity indices, though there was minimal indication of interactions between temperament and alkaloid exposure. This may imply that cattle with high exit velocities and those previously exposed to toxic endophyte-infected tall fescue are better poised against cell-mediated challenges.

Lower extremity ischemia due to combined drug therapy for migraine

Three days after initiation of migraine headache therapy with ergotamine tartrate and propranolol, severe acute arterial insufficiency of the lower extremities developed in a 48-year-old woman who had been in general good health. Angiography revealed hypoplastic aortoiliac arteries, with tubular narrowing of the leg arteries. Lower extremity blood pressures rapidly returned to normal with a single intraarterial injection of 25 mg of tolazoline. Cases of peripheral ischemia due to either ergotamine or propranolol have been reported. Combined use of these two drugs may enhance the risk of acute arterial compromise.

Effects of 5-hydroxytryptamine and ergotamine on human superficial temporal artery

Isometric tension was recorded in ring preparations of human superficial temporal arteries contracted by noradrenaline (NA), 5-hydroxytryptamine (5-HT), and ergotamine. In contrast to NA and 5-HT, ergotamine induced long-lasting contractions refractive to additional stimulations and resistant to repeated wash-out. When tested against 5-HT, ergotamine acted as a non-competitive antagonist. When repeating the 5-HT stimulations (4.7 x 10(-5) M) the contractile response decreased indicating tachyphylaxis to this agent. As ergotamine revealed both a vasoconstrictive and a 5-HT-blocking activity, the beneficial effect in migraine may be by an interference during both the vasoconstrictory and vasodilatory phases.

Successful treatment of ergotamine poisoning with sodium nitroprusside

A case of ergotamine overdosage which produced vascular insufficiency in a 26-year-old female is described. She was treated successfully with the intravenous infusions of sodium nitroprusside and low molecular weight dextran, and anticoagulation with heparin. It is suggested that sodium nitroprusside may represent the drug of first choice in this condition.

Saint Anthony's fire or carpal tunnel syndrome? (a case of iatrogenic ergotism)

A case of unilateral upper limb ischaemia from ergot overdosage is presented. An unusual feature was a median nerve neuropathy suggestive of carpal tunnel syndrome. The arteriographic appearances are demonstrated and management discussed.

Ergot-induced vasospasm of the lower extremities treated with epidural anaesthesia

No reliable treatment to reverse severe ergot-induced vasopasm is available. A case of ergotamine-induced vasospasm of the lower extremities is presented. A combined treatment of vasodilators, infusion of low molecular dextran and high epidural anaesthesia apparently prevented extremity gangrene from occurring.

Ergot intoxication: historical review and description of unusual clinical manifestations

Clinical ergotism as seen today results almost exclusively from the excessive intake of ergotamine tartrate in the treatment of migraine headache. Although both gangrenous and convulsive symptoms are seen in naturally occurring ergotism resulting from the ingestion of fungus infected rye, only gangrenous ergotism has been reported following the excessive ingestion of ergotamine tartrate. The symptoms of both iatrogenic and naturally occurring ergotism appear to result from regional ischemia caused by ergot induced vasospasm. This report discribes experiences in the diagnosis and management of two patients with unusual manifestations of iatrogenic ergotism. One patient presented with ischemia of all extremities and bilateral foot drop probably due to ischemic damage to the common peroneal nerves, a finding not previously described in ergot intoxication. The foot drop totally resolved in several months following the discontinuation of ergot. A second patient presented with unilateral leg ischemia and transient monocular blindness, both of which resolved after discontinuation of ergot. Both patients displayed typical angiographic findings of ergotism. There is no convincing evidence that any treatment other than discontinuation of ergotamine is of benefit in the treatment of iatrogenic ergotism.

Ergot poisoning

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