M.R.
Maybe the effects of being ADHD cause her anxiety that raise her blood pressure. If she was suddely able to keep her train of thought. People with ADHD have difficulty carrying their thoughts across the synapas-space between brain cells- and stimulants correct the neurotransmitter disfuction that cause them to "loose track." She may have relaxed because she realized that she could keep track of things; imagine how distrubing it would be to live like that, and to not be able to fix it?
Concerta is a form of ritialin. The delivery system is pattented. The pill has two chambers, one side is empty, and the other is full of liquid ritalin (methelphenadate.) As the pill absorbs fluid from her body into the empty side, it squeezes out the medication slowly over time. That is the timed released mechanism.
There are many ADHD medications that are more likely to cause side effects than concerta. Methelphenadate is well tested and very well tolerated by many people, and does not have a half life, so when it is out of her system it is out of her system.
More importantly, did it help her?
Anger and agitation are possible side effects, and an different stimulant may be better if that happens.
M.