Almost all the medications we take on a regular basis use the bloodstream as a means of transportation.
- When you take pills or capsules, the medicine is absorbed by the stomach lining and the small intestine, and then enters the bloodstream.
- Drugs enter the bloodstream through the lungs when inhalants are taken, in much the same way that oxygen enters the bloodstream when you breathe.
- Shots inject the drug into the lymph around cells, is collected in lymph ducts, and then makes its way into the bloodstream. Intravenous methods directly inject drugs into the bloodstream.
- Suppositories cause the drug to enter the bloodstream through the lining of the large intestine.
- With skin patches, the drug migrates through the skin and enters the lymph or the bloodstream.
Most heart diseases arise from hardening of the arteries, especially the buildup of fatty material along the inner lining of the arteries. Coronary arteries supply blood to the heart. When a blockage occurs, this flow is decreased. Heart medications target these blockages in several different ways. Nitrates dilate the veins, decreasing the oxygen requirements of the heart. They also dilate the coronary arteries to increase blood flow to the heart. Beta-blockers decrease the heart rate and the force of the heart's contractions. Aspirin prevents platelets in the blood from clotting and clumping on blood vessel walls.
Doctors may soon be able to monitor a patient's vital signs and release drugs into the body through an implanted microscopic biochip less than half the width of a human hair. For example, surgeons can implant a chip in the wound after an operation. The chip would slowly release anesthetic, preventing pain impulses from reaching the brain so the patient feels almost no pain at all. It could also be implanted in diabetic to monitor blood sugar levels painlessly.