Tooth extraction - bad nerve

I have an appointment to have a lower molar removed, but it isn't for a month. The nerve is jumpy now but the pain still responds to acetaminophen/ibuprofen. Years ago I had to have a root canal done on an upper tooth where the nerve had completely gone and was constantly painful. The novacaine didn't didn't work because the nerve had gone bad (I was also 5 months pregnant and had limited options for anesthesia).

I know the nerves are different for upper and lowers. If the lower molar's nerve goes bad before I can get the extraction done, will novacaine be useless?  

Thanks.

[Jerome Tsang, DDS]

It is possible for anesthesia to not work well with severe cases of pain or infection.  Assuming you aren't pregnant, I would say that you should continue with the pain medication as an anti-inflammatory to help calm the nerve/tooth down before you get your extraction.  If there is indeed pain, I would recommend getting it taken care of sooner.  You may want to ask your dentist if antibiotics or a different pain medication is needed.