Question

Question 2 You meet a naive graduate student who is excited because he has designed a new local anesthetic. Unlike other local anesthetics, he has designed the molecule to always be uncharged. He believes it will be more easily absorbed and therefore he predicts it will be more effective. Explain the error in his thinking. Include a diagram of the mechanism of action.

Answer 1

Local Anaesthetics are basically uncharged > The frror is if it is easily absorbable actually the local anaesthetic action determines by protein binding capacity of a local anaesthetic by conduction block More protein binding my More duration of action > If harger amount of Local Anaesthetic reaches the systemic circulation Supra therapeutic blood and tissue levels can cause toxicity inst Greater lipid solubility of a drug not only enhances potency but also Enables more rapid diffusion through cell membranes 7 for local Anaesthetics this hastens (cs the onset for Anaesthesia is Care

Isolated fibres during in vitro studies. → Vasodilating properties may promote systemic absorption before the Anaesthetic reaches the nerve membrane > High lipid solubility may inhede dispersion throughout tissue fluids sequestration in adipose tresue and myelin sheath fewer number of molecules may reach the nerwe fibres onset of action may delay Mechanism of action ; Rouped. Systemic absorption normally has a delayed onset . Nat Nat Local porpora n n AARRRRD 08998 en ARRA Anaes thetic debate Blocking Closed Nat Opened Nat for Channel a tong Slow onset of action leads to toxicity time & Allergy scanner & Anaphylaxis