FACTORS INFLUENCING LOCAL ANAESTHETIC BLOOD LEVELS
(i) Drug dose: Blood leels are proportional to the amount given. Increasing the dose also increases the extent of the block and increases the risk of local anesthetic toxicity.(ii) Drug type: Some drugs such as prilocaine are so rapidly metabolized (by plasma cholinesterase in this instance) that high blood leels are harder to achieve.
(iii) Pattern of absorption (Pharmacokinetics): Drugs injected intravascularly achieve a high peak leel shortly after injection, whilethose injected into a peripheral compartment (eg. infiltration into tissues) take a longer time to achieve a peak leel.
(iv) Site of administration: Administration of local anesthetics in highly vascular areas increases the likelihood of high drug leels.