Elvanse Adult is the only stimulant to be licensed for initiation of ADHD treatment in adults. Lisdexamfetamine is a pharmacologically inactive prodrug that is converted to dexamfetamine in the blood. It is taken once daily.
As in children, treatment with lisdexamfetamine in adults must be supervised by a specialist in behavioural disorders and undertaken as part of a comprehensive programme including psychological, educational, behavioural, occupational and social measures. Psychiatric and cardiovascular status, and the risk of diversion, misuse and abuse, should be assessed before and throughout treatment.
Four randomised, double-blind, placebo-controlled trials evaluated the efficacy of lisdexamfetamine in a total of 846 adults with ADHD.
In a 4-week study in 420 adults, treatment with lisdexamfetamine dimesylate significantly reduced the degree of functional impairment, as shown by improvements in the clinician-determined ADHD Rating Scale (ADHD-RS) total score of –16.2, –17.4 and –18.6 for the 30mg, 50mg and 70mg daily doses, respectively, compared with –8.2 for placebo (p<0.0001 for all).
A 10-week study evaluated the effect of lisdexamfetamine in 161 adults with clinically significant impairment in executive function.
Participants treated with lisdexamfetamine experienced significantly greater reductions from baseline in self-reported mean Global Executive Composite [GEC] T-scores on the Behavior Rating Inventory of Executive Function-Adult version (BRIEF-A) than those who received placebo (effect size 0.74; p<0.0001).
Attention in a simulated workplace
Wigal et al conducted a crossover study of lisdexamfetamine in a setting designed to simulate the workplace environment. They enrolled 127 adults to undergo a 4-week open-label dose titration phase, followed by randomisation to receive either their optimised dose of lisdexamfetamine for 7 days followed by placebo for 7 days, or placebo for 7 days followed by their optimised dose of lisdexamfetamine for 7 days.
Level of attention, as determined by the Permanent Product Measure of Performance (PERMP), was greater at all time points from 2 to 14 hours after dosing with lisdexamfetamine than after dosing with placebo (p≤0.0017 for absolute scores; p<0.001 for change from pre-dose).
Maintenance of lisdexamfetamine efficacy was examined in a withdrawal-design study. After receiving lisdexamfetamine for at least 6 months and maintaining response during a 3-week open-label phase at a stable dose, 116 participants entered a 6-week double-blind withdrawal phase in which they were randomised to continue treatment with lisdexamfetamine at the same dose, or switch to placebo.
At endpoint, symptom relapse occurred in 8.9% of adults taking lisdexamfetamine and 75.0% of those taking placebo (p<0.0001), indicating maintenance of efficacy compared with placebo.
Adverse reactions observed with lisdexamfetamine treatment mainly reflect those typically associated with stimulant use. Very common adverse reactions seen in adults include decreased appetite, insomnia, dry mouth and headache.