A key limitation of medication pumps is the eventual development of tolerance to the drugs. Dosages of pain medication can be increased as tolerance rises, but there are limits. That’s why this therapy is generally used for people with limited life expectancy or those in extreme circumstances. One main advantage of this type of device is that the medication is delivered directly to the site of action (spinal cord), and the effective dose can be reduced by 100 fold from the equivalent dose by mouth. This greatly reduces the risk of side effects from the medications.
Surgery to implant any pain device carries some risk of complications, such as infection, bleeding, or even the potential for spinal cord or nerve damage. Fortunately, the risks are quite low.
Nerve stimulators and medication pumps can work exceedingly well in the right situations. When effective, a reasonable goal with these devices is to reduce pain by at least 50 percent. The main objective is to reduce pain to a manageable level, allowing improved function and quality of life. — Halena M. Gazelka, M.D., Pain Medicine-Anesthesiology, Mayo Clinic, Rochester, Minn.