Abstract
Background ADHD affects 5% of children and young people (CYP) and, if untreated, can be associated with significant multi-domain impairments. Medications licensed for ADHD treatment are effective but can be associated with side effects. Stimulant medications (Methylphenidate and Dexamfetamine/Lisdexamfetamine) and Atomoxetine are associated with small but statistically significant increases in Blood Pressure (BP) and Pulse. Intuniv is an alpha 2a agonist, which can be associated with low BP and bradycardia. Thus, guidelines recommend regular monitoring of BP and Pulse and plotting the figures on reference centile charts. However, confusion can arise about which reference centiles to use due to differences in the cut-offs applied in different regions of the world. Both the American Academy of Pediatrics (AAP) and European Society of Hypertension (ESH) define hypertension (HT) in CYP as BP ≥95th percentile for gender, age and height on three or more separate occasions, while pre-hypertension (PreHT) (now redefined as elevated BP) is BP ≥90th percentile but less 95th percentile. However, the British reference for CYP between 4 and 23 years defined HT as BP above the 98th percentile for age, and ‘high-normal BP’ (PreHT) between the 91st and 98th percentile.
Objectives This audit aimed to describe the BP profile of a sample of otherwise healthy CYP on medications for ADHD attending routine clinical reviews, and to compare the proportions meeting cut-off for HT or PreHT/‘Elevated BP’ (EBP) based on British vs AAP/ESH reference definitions.
Methods Between March 2019 and March 2020, 67 CYP who attended routine clinician-led appointments for ADHD medication review had their BP and Pulse measured with electronic sphygmomanometers. The equipment was regularly calibrated and clinicians followed standard procedures for checking BP and Pulse.
Results Of the 67 CYP, 85% were males, and the average age of the cohort was 12 years. Based on the British definition, 12 (18%) were recorded as PreHT while 7% met the criteria for HT. The corresponding proportion of CYP meeting the AAP/ESH definitions for EBP and HT were 15% and 7.5% respectively. the CYP with HT or PreHT were monitored with non-clinic based BP measurements at home or by the GP and all returned to normal in the following eight months.
Conclusions The proportions of CYP classified by the British or AAP/ESH reference as having HT or PreHT were different albeit with small margins. However these small differences in proportion could have population-level implications if mapped onto the full cohort of CYP with ADHD attending similar medication reviews in the UK. Also, the differences could lead to frontline clinicians using different thresholds for triggering remedial actions in CYP with suspected HT such as medication dose reduction or paediatric cardiology referral. Therefore, we recommend further review of these different reference points to avoid confusion among front-line clinicians. One potential reason for the differences is that the British reference does not consider the CYP’s height. Perhaps, including height in the algorithm that determines all BP reference centiles for CYP would provide closer results.
