Convulsions, control

Table 11 summarizes values for the median lethal dose (LD q) for several species. In case of massive exposure, convulsions must be controlled, and glucose, fluid balance, and uriaary output must be maintained. Medical surveillance requires checking for damage to the Hver, the organ that apparently sustains initial damage, and monitoring for changes ia the blood profile. 

Chen et al. state that dendrobine produces moderate hyperglycemia, diminishes cardiac activity in large doses, lowers blood pressure, depresses respiration, inhibits isolated rabbit intestine and contracts isolated guinea-pig uterus. It has a weak analgesic, antipyretic action. Chen and Rose found that the convulsions induced by injection of dendrobine can be controlled by use of sodium isoamylethylbarbiturate they appear to be central in origin due to action on the cord and medulla. 

No acute-duration oral MRL was derived for endosulfan because no suitable end point was available among the reliable acute-duration studies. The lowest LOAEL, 1.8 mg/kg/day, was for a serious end point, convulsions in pregnant rabbits, appearing 10 days after the start of daily gavage dosing in the EMC (1981) study. Because animals from both the control and the test groups developed ascites, and six rabbits were added without concurrent controls, the reliability of these results is questionable. 

All such animal procedures suffer from the obvious and basic problem that laboratory animals do not behave like humans and that humans cannot reliably interpret their reactions and behaviour. Thus we know that Parkinson s disease is caused by a degeneration of the dopaminergic nigrostriatal tract but its lesion in animals does not produce any condition which resembles human Parkinsonism, except in primates, even though there are functional tests (e.g. rotational movements) which readily establish that loss of dopamine function and also respond to its augmentation (Chapter 15). By contrast, there are many ways, e.g. electrical stimulation and the administration of certain chemicals, to induce convulsions in animals and a number of effective antiepileptic drugs have been introduced as a result of their ability to control such activity. Indeed there are some tests, as well as animals with varied spontaneous seizures, that are even predictive of particular forms of epilepsy. But then convulsions are a very basic form of activity common to most species and epileptic seizures that are characterised by behavioural rather than motor symptoms are more difficult to reproduce in animals. 

Ventilate the patient. There may be an increase in airway resistance due to constriction of the airway and the presence of secretions. If breathing is difficult, administer oxygen. As soon as possible administer of atropine alone or in combination with pralidoxime chloride (2-PAMC1) or other appropriate oxime. Diazepam may be required to prevent or control severe convulsions. If diazepam is not administered within 40-minutes postexposure, then its effectiveness at controlling seizures is minimal. 

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