I remember reading on a previous post somone has gotten better only using orals.
I guess it would depend on years of infection and with what one is infected with?
Teddi
I did 4 months of IV's because I have had lyme for over 30 years. Also my stomach is very sensitive. I have lots of nausea as a lyme symptom. I tried Doxycycline for a week and did not tolerate it. So we decided on IV.
It is also considered if you have a lot of neuro lyme symptoms.
But many have improved with just orals. So it really varies per patient, just like all the crazy symptoms we get.
Best,
Karen
The orals were happening while trying to get the IV antibiotic approved by my insurance company (which still hasn't happened). 
I started IV antibiotics 2 weeks ago, and am seeing improvement in my energy level and cognitive functioning.
Perhaps it is a combination of all the antibiotics, or perhaps it is because the IV does a good job of crossing the blood brain barrier.
I did have a lot of neuro symptoms, and Dr. F in NY recommded IV antibiotics over oral for me.
You can read some stuff on his website www.columbia-lyme.org.
Also, the CDC website recommends IVs for those with neurologic lyme. (I used some of their stuff and Dr F's to appeal my insurance companies decision.) 
I am glad to be doing the IV. The picc line is no big deal at all.
Tina