Kava is considered to be a form of 'herbal' valium. There are several ways in which it is believed to have its anxiety-reducing effects. For instance, it is speculated that in the amygdala, a major part of the anxiety/fear system, kava works to 1) enhance binding at GABA receptors, 2) block the re-uptake of norepinephrine, and 3) decrease the activity of monoamine oxidase.
If you go online to look up the side effects of kava, you'll find the following: Higher doses and long term use can lead to hypertension, shortness of breath, mild GI symptoms, enlarged pupils, and possible pulmonary hypertension. Assume that kava acts on the body in a similar way as it does in the brain. Please explain why we see these side effects.