By Michael Bosse, PharmD
TCOYD Newsletter, Vol. 27, 2008

We all know there is no such thing as a “natural” miracle cure for any type of illness. There are, however, a multitude of natural products that have been, or are being used to treat diabetes, obesity, and many other conditions. Some people swear by them while others swear them off. Regardless of your philosophy on the use of natural medicines and supplements, it is important to understand from a pharmacy standpoint how your body processes them.

ADME: It’s Not Peer Pressure, Every “Body” is Doing It
ADME stands for Absorption, Distribution, Metabolism and Excretion and it represents how your body processes everything you put into it: food, prescription drugs, over the counter (OTC) products, supplements and natural remedies. Whether you had it prescribed, purchased it over the counter at a health food store, grew it or bought it online, anything and everything you ingest, inject, apply or inhale MUST go through ADME. There are no exceptions.

Whether you believe it or not, you have been exposed to ADME before. It is the baritone voice barking out warnings near the end of a prescription drug TV commercial while the happy couple on screen frolic gleefully on the beach “Take on a empty stomach (Absorption); Talk to your doctor if you have circulatory disease (Distribution); Do not take if you have active liver disease (Metabolism); Talk to your doctor if you have kidney disease (Excretion).”

Modern Day Medicinal Heirogyphics

Can you tell which of the figures pictured is a natural product? These are the chemical structures of some very common prescription and natural products. Your body interprets these structures on a chemical level and applies the ADME principles accordingly. Figure 1 is metformin, which works primarily in the liver where sugar is made. Figure 2 and Figure 3 lower cholesterol, with Figure 2 being the natural product red yeast rice and Figure 3 being the prescription drug Zocor (simvastatin). Can you see the similarities in the ring structures? Figure 4 is the anti-depressant Celexa (citalopram). It needs to get into the brain to exert it effects. The point being that your body does not differentiate, it goes to work on whatever you put into it, regardless of whether it is natural or prescription in origin.

A: Absorption
Pills, injections, creams, syrups, elixirs, inhalers, and suppositories all have one thing in common; they want to get into your body and exert an effect. How they get to intended site of action depends on how your body absorbs them. Oral pills need to be broken down into their active ingredients, like the chemical structures above, and properly absorbed into the blood stream. Most medications found in inhalers are designed to be absorbed in the lungs, appropriate because this is their primary site of action. Ever wonder why there is no insulin pill? Because insulin is a protein, it would be broken down by the high acid content of the stomach and would never be absorbed into the blood. When given by injection into the subcutaneous tissue of the abdomen, insulin bypasses the acidic stomach and is absorbed into the blood via the layers of fat just below the skin.

D: Distribution
Now that the drug made its way in and has been properly absorbed, where does it go from there? It is distributed into your body according to its chemical make-up. Actos (pioglitazone) needs to be distributed to cells of the body that utilize sugar, specifically into the nucleus and DNA of these cells where it exerts its blood glucose lowering effects. Anti-depressants work by crossing the blood brain barrier (BBB) and increase chemicals in the brain to improve depressive symptoms. An anti-itch cream such as 1% hydrocortisone is mostly distributed right where it is applied, on the skin, and does not enter the blood stream. ALL medications are distributed according to their chemical properties as illustrated by the ring structures above.

M: Metabolism
When a drug or natural product enters the body, the process of metabolism begins as your body attempts to break it down into usable pieces. Much the same way food is broken down into sugar, fats and proteins, medications suffer a similar fate generally at the hands of the liver and the enzymes of the cytochrome P450 system. Think of this complex system as lanes on the freeway, with every drug, nutraceutical and supplement having a preference for one particular lane. Based on their chemical make-up, many drugs and natural products like to use the same lane to be metabolized. Some natural products such as St. Johns Wort “block” many of these lanes used for metabolism of prescription drugs, increasing the chance for toxicity or unwanted side effects. When this delicate balance of metabolism is altered by disease or other drugs, prescription or otherwise, the result is often times not pleasant and sometimes scary. When a new medication is started and throughout the course of treatment, your doctor may order blood tests to check on the health of your liver.

E: Excretion
Once drugs have exerted their effects, the body decides it is time to get rid of them. The major routes of elimination are the urine via the kidneys and the feces via the liver. “Half life” refers to the time it takes for your body to excrete or eliminate 50% of any given drug. Generally, medication with a long half life is given once a day and drugs with shorter half life are given two or three times a day. Disease or damage to either the kidneys or liver can impair the way drugs are removed. Often times medication dosing regimens are changed based on the degree of kidney damage or liver disease as assessed by a physician.

The take-away from this is to speak with your physician or pharmacist about ALL medications you take to manage your health— natural, OTC, prescription or otherwise. These all work off of ADME principles and therefore the potential for pharmacological issues exists, drug interactions, decreasing effectiveness, toxicities, etc. Natural does not always equal a better outcome any more than prescription always means a better way to treat your health.

Michael Bosse, PharmD, is owner of A1c Rx Pharmacy in California

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