Safe Prescribing of Pregabalin in Sciatica

Problem

Back pain accounts for up to 7% of GP consultations, with Sciatica being a common cause. Pregabalin is one of four medications recommended in the treatment of neuropathic pain. Our aim was to see whether guidance provided by NICE and SIGN on the initiation of treatment and adjustments required in renal impairment were being adhered to.

Approach

EMISweb tool was used to search for patients with a code of ‘Sciatica’ and concurrently prescribed ‘Pregabalin within the last 6 months’. In total 24 patients were identified with 1 patient coded with ‘Sciatica‘ excluded due to Pregabalin being prescribed for a reason other than sciatica. The remaining 23 patients consultation notes, medication history and blood tests were reviewed since being initiated on Pregabalin.

Findings

4 aims were outlined at the beginning in the project; The first focussed on patients having an eGFR within the last 12 months, or recorded within 2 weeks of initiating Pregabalin. 3/23 patients did not have any documented evidence of a recent eGFR as outlined above. Of those with a documented eGFR, 4 patients were identified with an EGFR of between 30-60, and as per NICE guidance should be initiated on 75mg a day (divided in two or three doses) and a maximum daily dose of 300mg (divided in two or three doses). All 4 patients exceeded the initiation dose recommendation, with doses prescribed including 75mg BD for two patients, 50mg TDS for a third patient and 75mg OD. 100% of patients did not exceed the maximum daily dose, with maximum doses of 75mg BD, 75mg OD, 50mg TDS and 150mg BD prescribed. The final aim was to ensure early review following initiation of Pregabalin, defined as within 4 weeks of Pregabalin initiation as suggested by SIGN. Of this cohort 6/23 were seen within 4 weeks.

Consequences

In conclusion I believe in this study I have highlighted a gap in the knowledge of primary care clinicians when prescribing Pregabalin. The main area is in the incorrect initiation of Pregabalin therapy in renal impairment, which resulted in 4 prescribing errors, but also could have occurred, in the long-term maximal therapy when up titrating treatment. There also seems to be a lack of knowledge and awareness when it comes to the importance of an initial renal function, with 13% of patients not having any bloods prior to or upon Pregabalin initiation. There is also scope for clarification from NICE as to what would be an appropriate time scale for review following Pregabalin initiation, as if it was within 4 weeks as suggested by SIGN then only 26% of patients were appropriately followed up.