Among the following local anaesthetics, the one that is associated with vasoconstriction and mydriasis is :
Local application of cocaine causes blockage of initiation and conduction of nerve impulses. It also blocks neuronal re uptake of nor epinephrine thus potentiating adrenergic activity. Ocular effects of cocaine includes anaesthesia, mydriasis and vasoconstriction. Mydriatic effect of cocaine depends upon presence of a functioning adrenergic innervation. Procaine causes vasodilation hence it is usually given with adrenaline. The main shocomings of procaine are: Being a vasodilator, when it is given in the absence of a vasoconstrictor agent procaine is rapidly absorbed into the circulation and hydrolysed by plasma cholinesterase. Hypersensitivity to procaine is commonly encountered. Ref: Clinical Ocular Pharmacology edited by Jimmy D. page 119. Principles of Pharmacology: A Tropical Approach By D. T. Okpako page 403.
Cocaine
Bupivacaine
Procaine
Lignocaine