OBJECTIVES: In the UK, Oral Anti-Diabetic drugs “OAD” are administered to control hyperglycaemia in type 2 diabetes when HbA1c exceeds 48mmol/mol. Treatment guidelines determine initial OAD and subsequent changes in regimen depend on HbA1c response. Hence, the aim of this study is to quantify OAD treatment patterns. METHODS: All patients who initiated an OAD (except rosiglitazone) with first use as index date, in the GPRD database between 1/1/2006 and 25/2/2011 were included. Periods of continuous and overlapping prescribing (Rx) were used to define discontinuation, switching and augmentation; a gap of 60 days since expiry of Rx defined discontinuation. RESULTS: Of 63060 patients commencing OAD, 88% started on metformin and 8% on gliclazide both as monotherapy. Hence, all other OAD regimens comprised only 4% of all patients. Compared to metformin, the gliclazide patient group was older (mean age 67 vs. 61 years) and had higher median baseline HbA1c (70 (IQR 60-95) vs. 64 (IQR 56-74) mmol/mol). The rate of discontinuation of baseline OAD at one year was 32% whilst the discontinuation of all OAD was 26%. It was rare for discontinuation of OAD to be permanent; only 3.3% of patients who discontinued in the 1st 12 months did not restart during 4 years. The rate of switching was 6.4% and the rate of augmentation was 15% over the first year. These rates differed according to baseline OAD. Compared to metformin the discontinuation rate of gliclazide was higher (41% vs. 30%), as was switching (8.4% vs. 6.1%) and augmentation (23% vs. 14%). Lastly, insulin uptake was just 2% by one year since OAD initiation; again this was higher in the gliclazide group compared to metformin (7% vs. 1.4%). CONCLUSIONS: Most patients initiated on metformin, whilst for those initiating on gliclazide, discontinuation, switching, augmentation and insulin initiation were all higher. Most patients who discontinued OAD subsequently restarted.