Background Patients taking oral pain medication may suffer from side-effects, especially if they take high doses of medication. For some people, these medications can be administered directly intrathecally (into the fluid around the spinal cord) using a pump implanted under the skin, This allows lower doses to be used, which results in fewer side-effects. Your doctor thinks you may benefit from this kind of medication delivery system, Not everyone gets pain relief from intrathecal medication and some patients may still experience side-effects, so it's important top have a trial of intrathecal medication before having a permanent pump implanted. This allows you and your doctor to assess whether this treatment is suitable for you. What is involved in the procedure? On the day of the procedure, you will be admitted to hospital and the nurses will prepare you for theatre. In a trial of intrathecal medication, your doctor will inject a single dose of medication into the fluid around your spinal cord through your lower back. After the injection you will be taken back to your room, and normally stay in hospital overnight. A few weeks after the procedure you will have a follow up appointment with your doctor. You should attend this appointment at our office. What are the possible complications? This procedure has very low risk of complications but there are some of which you should be aware. Local discomfort: some patients may experience some discomfort in the area of the injection for a few hours or a few days. This is the most common complication. Post-dural puncture headache: very occasionally patient may develop a headache which is worse when standing up. Please contact our office if you develop a headache after the procedure. Bleeding or infection: these are very rare. Please contact our office immediately if you develop a fever or worsening back pain. If these symptoms occur outside of office hours, you should attend the nearest emergency department.