Standard caffeine intake is generally recognized as safe by the FDA and AMA but can be dangerous with adverse effects such as high bp, stroke, and arrythmias reported. If more than 1-2 cups of caffeinated beverages are consumed per day, it is prudent to seek physician and/or pharmacist approval of caffeine consumption with any medications or supplements. Please see caffeine section for more detail.
Cocoa and chocolate contains not only caffeine, but also theobromine which is known to act as a stimulant, vasodilator, and diuretic which may be responsible for some of the therapeutic action of cocoa (52). Theobromine and cocoa may intensify the blood pressure lowering effects of any blood pressure medications. Therefore a physician should oversee the care of a patient taking higher doses of cocoa or chocolate for high blood pressure than typically found in foods.