Kind regards! You are experiencing neuralgic pain,which is classified as one of the worst! Capsaicin allegedly ``drains`` and impairs the resynthesis of the notorious substance P in peripheral nerve endings. Substance P is in many studies since it is thought to be important neurotransmiter in many chronic conditions and processess (pain,inflamation............). But what it boils down to is this : You will be using Capsaicin locally (topical), a substance quite natural with very little chance of systemic side effects,which could very likely alleviate your trouble. When You put that on one side of the scale, and when You see what is offered to You on the other side (analgetics,tricyclic antidepressants,tranquilizers,carbapine,antiepileptics......all used systemicaly,intravenous,intramuscular,as tablets and pills) with many,many side effects,interactions and potential hazards and with no guaranteed success...................Of course,postherpetic neuralgia can last for quite some time,and maybe you will reach for some of these drugs anyhow,but Capsaicin is definitely a most benign first step and a definite ``lesser evil``. I wish You all the luck and strenght to overcome Your predicament!!!!!