The lower the ratio, the more potentially hazardous the drug is. This is the reason why we don't use bupivicaine for iv regional blocks. The treatment is supportive. Treat convulsions with phenytoin or barbiturates. If you were to use adrenaline, which drugs would you add it to .
Adrenaline is a local vasoconstrictor.
Less systemic absorption, and consequently lower toxicity and possibility of giving a higher dose. Prolonged duration of action. It is conventional to use adrenaline only with short acting agents such as lignocaine, as it has little effect on the duration of action of longer acting drugs. Tell me about Prilocaine. Prilocaine is equipotent with lignocaine, but its duration of action is longer and it is less toxic.