Investigators Find Repurposing Amlodipine as Novel Treatment for ADHD
The study authors report that long-term daily administration of amlodipine induced behavioral changes in the rats during their open field test.
Repurposing amlodipine, a medication commonly used for blood pressure, shows potential as a novel treatment for attention-deficient/hyperactivity disorder (ADHD), according to the results of a study published in Neuropsychopharmacology. Investigators of the study aimed to determine if 5 potential drugs could reduce ADHD symptoms in rats.1
ADHD is a prevalent neurodevelopmental condition, according to the study authors, and when left untreated, it can be associated with functional impairments. | Image Credit: ClareM | stock.adobe.com
"Repurposing amlodipine, a well-established blood pressure medication, offers a promising and swift pathway to address ADHD symptoms. Our research indicates that, due to its existing approval and safety profile, amlodipine could be rapidly redeployed as a treatment option for ADHD, potentially providing relief to patients sooner than developing new medications,” Matthew Parker, BSc MSc PhD FHEA, co-author of the study from the University of Surrey, said in a news release.1
ADHD is a prevalent neurodevelopmental condition, according to the study authors, and when left untreated, it can be associated with functional impairments, a heightened risk of mood and anxiety disorders, and a potentially increased risk of suicide. ADHD treatment typically involves stimulant medications, which can include adverse effects (AEs) such as appetite loss, hypertension, headaches, and sleep disturbances. Additionally, second-line treatment can also have AEs and has less efficacy compared to stimulants.2
Amlodipine is an oral dihydropyridine calcium channel blocker that is approved for indications such as hypertension, chronic stable angina, vasospastic angina, and angiographically documented coronary artery diseases, according to StatsPearls. Further, amlodipine can also be used for off-label diabetic nephropathy, left ventricular hypertrophy, silent myocardial ischemia, and group 1 pulmonary arterial hypertension.3
The 5 medications chosen were aceclofenac, amlodipine, doxazosin, moxonidine, and LNP599. Investigators aimed to determine if there were potential applications for these medications in ADHD therapeutics with human genetic modeling. In the rat model, investigators divided them into 7 groups. For 30 days, the groups were administered a control vehicle, clonidine, moxonidine, doxazosin, amlodipine, aceclofenac, or LNP599. Another group of rats were also dosed with a vehicle. The open field tests were conducted twice for all rats, with 1 test before dosing and 1 on the 29th study day.2
The study authors reported that long-term daily administration of amlodipine induced behavioral changes in the rats during their open field test, but the effects of all the other tested drugs were non-significant. Amlodipine showed reduced indices of hyperactivity, such as distance traveled and ambulatory time. However, there were no significant differences for rearing time between vehicle-treated and amlodipine-treated female or male rats. At day 29, investigators found that female rats treated with amlodipine had reduced distance traveled compared to vehicle-treated female rats, but this was not found in male rats.2
“The results further suggest that amlodipine may affect ADHD-related behaviors differently depending on sex, potentially due to variations in drug metabolism, hormonal interactions, or neural circuitry. Understanding these mechanisms could help tailor ADHD treatments more effectively for both males and females,” concluded the study authors.2
