Immediate and long-term effects on hormone levels following bites by the Burmese Russell's viper.

Studies of anterior pituitary function were made in victims of a bite by the Burmese Russell's viper, who had required admission to a renal unit. Twenty patients at the stage of the acute illness were studied using a single blood sample for several hormone assays. None showed normal levels of all hormones measured. As acute severe illness can have a profound effect on the levels of these hormones, it is only possible to conclude that the results were compatible with although not diagnostic of anterior pituitary failure. Twelve survivors were assessed at eight to 226 weeks after envenoming, by hormone measurement in a basal sample, and a combined pituitary reserve function test with TRH, GnRH, and insulin hypoglycaemia. All but one showed some deficit in pituitary hormone secretion. Seven had already been started on thyroid replacement therapy or corticosteroids. Three survivors were assessed in the acute stage and later and each had similar findings on both occasions. Three survivors who were followed up and assessed with a combined pituitary reserve function test on two occasions had similar results each time. There was no sign of recovery. It seems that severe envenoming may be associated with anterior pituitary failure. Results from five autopsies showed that the lesion was haemorrhagic anterior pituitary necrosis. An additional mechanism may be direct action of the venom upon the function of anterior pituitary cells. We conclude that severely affected victims should be considered at risk of pituitary insufficiency.