Long- and Short-Acting Methylphenidate Consumption in South Africa

OBJECTIVES: Methylphenidate is used for disorders such as narcolepsy, depression, obesity and cognitive disorders, but nowadays most commonly prescribed for Attention-Deficit/Hyperactivity Disorder (ADHD). Based on its half-life, dosing of 2-3 times daily up to a maximum dose of 60 mg/day for adults and paediatrics is required. To improve the overall effectiveness, long-acting formulations allowing for once daily dosing are available. The objective was to analyse the consumption patterns of methylphenidate in South Africa by means of a drug utilisation study using the Defined Daily Dose (DDD) methodology.

METHODS: The Intercontinental Marketing Service (IMS) database, containing the private healthcare sector medication sales per month for South Africa, was used to review the sales data of methylphenidate from 2013 to 2016, to establish trends. All the available short- and long-acting methylphenidate-containing products in South Africa were included in the study.

RESULTS: The monthly consumption of methylphenidate showed slight increases over the study period. In October 2013, the highest consumption for the year was 1.194 DDDs/1000 inhabitants/month followed by November (1.174 DDDs/1000 inhabitants/month). In 2014, the highest consumption was in June followed by November (1.405 and 1.404 DDDs/1000 inhabitants/month, respectively). In 2015, the months with the highest consumption were November and September with the DDDs/1000 inhabitants/month being 1.617 and 1.460, respectively. In 2016 the highest consumption was in February followed by November with the number of DDDs/1000 inhabitants/month being 1.625 and 1.552, respectively. The highest methylphenidate consumption was observed with long-acting tablets.

CONCLUSIONS: The higher consumption observed for methylphenidate in November is possibly due to examinations for South African patients that are studying at schools or tertiary institutions. Evidence of drug holidays, where the amount of medication consumed was lower, was noticeable in the months of July and December. The occurrence of drug holidays is in keeping with other South Africa studies.