What is Intrathecal Drug Delivery

What is Intrathecal Drug Delivery? Dr. Ken Follet: Intrathecal Drug Delivery involves the administration of pain relieving medications directly into the spinal fluid. Many pain medicines, for example, morphine pills actually work at least in part in the spinal cord. When a person takes a pain pill by mouth, it eventually gets into the bloodstream, it has to travel through the entire body, little bit of it eventually gets to the spinal cord where it can do its work. The problem with that approach is that sometimes in order to get enough pain medicine to the spinal cord to relieve pain effectively, in essence we saturate the rest of the body and this can cause side effects, sleepiness, nausea, constipation. The advantage of intrathecal drug delivery is that we can actually infuse the medicine in liquid form directly into the spinal fluid. Once the medicine is in the spinal fluid, it in essence floats up and down around the spinal cord. It soaks into the spinal cord, just like a sponge would soak up water. So the medicine is being delivered where it does its job. Because the medicine is being delivered to its site of action, it tends to be much more effective in terms of relieving pain. Secondly, because it doesn't really leave the spinal fluid compartment, we eliminate or reduce many of the side effects. So the net result is more effective pain relief with fewer side effects. Dr. Nagy Mekhail: It is a different way of administering medications. Morphine can be taken by mouth or can be taken through the skin or through -- but another way of delivering the medication is through the spine. Dr. Ken Follet: The Intrathecal Drug Delivery system consists of two parts. There is the pump itself which contains the electronics the pump mechanism and which also has to be large enough to hold the supply of medication, and there is this a very thin soft catheter, which is tunneled under the skin and implanted in the spinal canal in the lower back, through which the medication is delivered. Dr. Nagy Mekhail: One major advantage is that minute amount of medication is required in the spine to achieve effect. If somebody is requiring 300 milligrams of morphine by mouth, all what you need in the spine to achieve equivalent pain relief is 1 milligram. So you end up using a very small amount of medicine, you are delivering it exactly where you need it, in this spine around the nerves. Dr. Ken Follet: The small pump is typically implanted under the skin of the abdomen. This is large enough to hold a supply of medication that typically lasts anywhere from two to four months. It's connected to a very small tubing that we call a catheter, which is tunneled underneath the skin and implanted in the spinal canal in the back. So again, everything is underneath the skin when we are done. The pump is refilled easily, when it's due for a refill, patients come back to the physician's office. We washed the skin of with an antiseptic soap. Simply poke a needle through the skin into a small rubberized opening on the pump and inject another batch of medicine, takes 5 or 10 minutes. Dr. Nagy Mekhail: And the side effects would be less. So instead of having these people like zombie, like sedated, and not communicate, they feel much better and at the same time less side effects. Dr. Ken Follet: The surgeries to implant either a drug infusion pump or neurostimulator are simple surgeries, they are safe. They generally take no more than one hour, one-and-a-half hours. In many centers the surgeries are performed on an outpatient basis. Patients go home at the same day of surgery. Other centers may wish to keep patients one night or perhaps two nights to monitor their condition. If we implant a drug infusion pump, we may wish to keep the patient in the hospital a day or two, just to begin the infusion of the medication and watch for side effects.