
Clonidine and Guanfacine
Clonidine and guanfacine began as treatments for hypertension but have been found useful in managing attention-deficit/hyperactivity disorder (ADHD). Both drugs can cause adverse effects such as drowsiness, headache, dry mouth, and slowed heart rate, which can be intensified after an overdose. Swallowing even one tablet or coming in contact with a patch can cause toxicity in a child.