Cardiac or central nervous system toxicity may result when standard lidocaine doses are administered to patients with circulatory failure. This may be due to the following reason -
Ans. is 'a' i.e., Lidocaine concentration are initially higher in relatively well perfused tissues such as brain and hea o Lidocaine is a rapidly acting drug because of its rapid distributtion to well perfused tissues such as brain and hea.o Circulatory failure is characterized by decreased cardiac output and a consequent decrease in hepatic blood flow.As a result metabolic clearance ofLidocaine in liver is diminshed and its elemination t 1/2 is increased. Consequently Lidocaine concentration is initially increased in these relatively well perfused tissues (brain and hea) even with usual doses and toxicity results.
Lidocaine concentration are initially higher in relatively well perfused tissues such as brain and hea
Histamine receptors in brain and hea gets suddenly activated in circulatroy failure
There is a sudden out-burst of release of adreneline, noradreneline and dopamine in brain and hea
Lidocaine is conveed into a toxic metabolite due to its longer stay in liver