Why Pharmacokinetics matters.

By David Joel Miller.

What is pharmacokinetics and why does it matter?

Drugs affect the body.

Why Pharmacokinetics matters.
Drugs affect the body.
Photo courtesy of Pixabay.com

Drugs are everywhere in our society. Not just Street drugs, or the legal drugs such as tobacco and alcohol. Most of us are exposed to drugs all day, every day. Even the people who say they “don’t do drugs” should be concerned about drugs and pharmacokinetics. When we hear about drugs, most of us think illegal drugs. It’s easy to overlook the long-term effects of use and abuse of prescription medication, over-the-counter medication, and the vitamins and herbal remedies all around us every day.

Pharmacokinetics deals with how drugs enter the body, how they get absorbed, how they get transported and delivered throughout the body, and ultimately how are drugs eliminated from the body. In a past post, we talked about routes of administration; the way drugs get into the body.

How much of that drug did you take?

For most drugs the more you take, the stronger the effect. Let’s take a simple, common drug, alcohol to illustrate this principle. If someone drinks a twelve-ounce beer, they consume about half an ounce of pure alcohol. Drinking twelve ounces of whiskey will result in the consumption of about six ounces of alcohol. With whiskey, you drink the same amount of liquid, but because the whiskey is more concentrated, you received a much higher dose of Alcohol than the beer drinker does. Measurement of alcohol consumption requires the use of an idea called the standard drink.

Drug dose is computed based on body weight.

A three-hundred-pound man will need to take a higher dose of medicine than a twenty-pound child. Heavier people contain more volume of liquids, so any chemical they take into their system becomes more dilute. For most medications, your Doctor will want to know your body weight, so they know how much medication to give you.

When it comes to Street drugs or even alcohol, most people don’t consider the effect that body weight has on the drug using experience. Thin people will get higher blood concentrations of the drug even when they take the same amount. Recently we have seen many people who had weight loss surgery, lost a large amount of weight, and developed a significant problem when they consume alcohol or other drugs.

Drug absorption matters.

Some drugs are readily absorbed into the bloodstream. When you consume liquid drugs or very soluble ones, they readily pass through the stomach, into the intestine, and are absorbed into the bloodstream. Solid drugs vary a great deal in their bioavailability, which is the part of the drug that becomes absorbed into the bloodstream and reaches the site of action.

An example of the problem of bioavailability involves pregnant women. Calcium is often added to the diet of a pregnant woman to help the fetus develop strong bones. Limestone is high in calcium, but no matter how much you grind it up, most of the limestone will pass through the body undigested. How much of the calcium in your vitamin supplement will be absorbed into your bloodstream, it’s bioavailability, matters.

Drug distribution varies from drug to drug.

Drugs that are highly water-soluble travel readily throughout the body. Blood nourishes all the cells in the body, and the parts of the body that received the most blood also received the largest doses of drugs. Drugs tend to accumulate in the heart, brain, kidney, and liver. Parts of the body that get little blood flow, the muscles and fat, received little of the active drug. Can you see why taking an oral supplement to “melt away fat” is unlikely to work?

A few drugs, such as THC in marijuana, are fat soluble. These drugs will tend to accumulate in the parts of the body which have the largest fat content.

Drug elimination – how the drug leaves the body.

Eventually, any drugs that go into your body will get broken down and eliminated. Many drugs are metabolized by enzymes produced in the liver. These drugs are especially hard on the liver when taken in excessive quantities. This process is the reason heavy alcohol consumption increases the risk for four separate types of liver disease.

Some drugs are metabolized in the kidneys or the G.I. tract. Regardless of where the metabolism takes place, the majority of all drugs are removed from the body by the kidney. Some drugs, especially in large quantities, can be very hard on the kidneys. Drug abuse can result in impaired kidney function resulting in the need for kidney dialysis.

Drug metabolism is a sequential process.

Many drugs are broken down in stages. The first breakdown product is then metabolized into a second breakdown product and so on. These breakdown products or metabolic byproducts may also be psychoactive. When both cocaine and alcohol are present in the system, they and their metabolic byproducts can combine to produce Cocaethylene which is even longer lasting than the original cocaine and alcohol.

For more on this topic see – Drug Use, Abuse, and Addiction and Recovery

Staying connected with David Joel Miller

Two David Joel Miller Books are available now!

Bumps on the Road of Life. Whether you struggle with anxiety, depression, low motivation, or addiction, you can recover. Bumps on the Road of Life is the story of how people get off track and how to get your life out of the ditch.

Casino Robbery is a novel about a man with PTSD who must cope with his symptoms to solve a mystery and create a new life.

For these and my upcoming books; please visit my Amazon Author Page – David Joel Miller

Want the latest blog posts as they publish? Subscribe to this blog.

Want the latest on news from recoveryland, the field of counseling, my writing projects, speaking and teaching? Please sign up for my newsletter at – Newsletter. I promise not to share your email or to send you spam, and you can unsubscribe at any time.

For more about David Joel Miller and my work in the areas of mental health, substance abuse, and Co-occurring disorders see my Facebook author’s page, davidjoelmillerwriter. A list of books I have read and can recommend is over at Recommended Books. If you are in the Fresno California area, information about my private practice is at counselorfresno.com.

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Why do drugs affect people differently?

By David Joel Miller.

Many factors affect the way people experience drugs.

Drugs

Drugs.
Photo courtesy of Pixabay.com

Whether it’s legally obtained drugs, or the prescription kind, obtained from a drugstore with a doctor’s prescription, the way people experience those drugs varies widely. Recently we’ve seen an epidemic of deaths because of use and abuse of prescription pain medication. Some people are in chronic pain; pain medications alleviate their suffering and allow them to function. Other people like the way those drugs make them feel or the way they keep them from having to feel anything.

People who take powerful painkillers for emotional reasons, to get high, run a high risk of becoming addicted. Three characteristics of addiction tell us that as people develop tolerance, experience withdrawals, and begin to have cravings for a drug of abuse, the risk that will take larger and larger amounts increases.

What are some of the factors that affect the drug using experience and may result in drug use turning into abuse, addiction, and the development of the drug use disorder?

Drug dosage influences the using experience.

With most drugs, small amounts of drugs produce smaller effects. Common over-the-counter pain relievers a relatively safe and not likely to cause addiction when taken as directed. Take large amounts of over-the-counter pain relievers and the risk of permanent damage to your liver or kidney, possibly even death, becomes a real possibility.

Drink one standard drink, let’s say a single twelve-ounce beer, each day, and you’re not likely to develop an alcohol use disorder. Drinking a six-pack a day and you will begin to build tolerance. Eventually, that drinker will need to drink a case of beer a day to feel the same effect. The higher the blood alcohol content goes on anyone drinking occasion, the more the risks.

A large percentage of the people in America have tried marijuana. Most find it doesn’t affect their lives. But a small number of marijuana smokers voluntarily seek treatment for cannabis use disorder.  What is different about the people who seek out treatment for a marijuana-related problem? Most of the people who develop problems marijuana smoke every day and the quantity they smoke has increased over time.

When it comes to opiates, stimulant drugs, or other recreational drugs, the higher the dose, the more the risk.

How the drug gets into your body affects the experience.

The way in which drugs enter the body is referred to as route of administration.

Let’s use opiates as an example. It’s possible to smoke heroin, the high is experienced almost instantaneously, but a lot of the potency is lost in the process of smoking. Any drug that is smoked produces a rapid high and equally rapid withdrawal.

An equal amount of heroin mixed into a beverage and swallowed will be slower to take effect. Much of the potency is destroyed as the drug goes through the stomach. Stomach acids neutralize a large part of the potency of many drugs.

That same dose of heroin can be injected, producing a much more intense effect when the large dose reaches the brain. People who inject drugs experience much more intensive effects.

Psychological factors alter the experience of drug use.

Psychological set, the mood someone is in impacts the drug using experience. Someone who is in a happy mood and drinks alcohol may feel an increase in their happiness. They are celebrating. Someone who was angry and drinks may become angrier and more likely to act on that anger as the alcohol disinhibits them. A person who is sad and depressed who drinks alcohol is at an increased risk of developing severe depression and possibly making a suicide attempt.

Setting, the place where someone uses the drug, also alters the effects of the user experiences. Millions of people receive painkillers while in the hospital. Most of them do not become addicted. But the same quantity of drugs, purchased in an alley from a drug dealer for recreational use, are much more likely to result in a substance use disorder.

Other psychological factors that alter the drug using experience are the placebo effect and the Nocebo effect.

Your belief that the drug will have a beneficial effect is likely to produce that effect, whether that effect is positive or negative. If you think a pill will cure your headache, it probably will, even if it does not contain any active ingredient. People who believe that a particular medication will give them headaches are more likely to get headaches even when the pill is a sugar pill.

For more on this topic see – Drug Use, Abuse, and Addiction and Recovery

Staying connected with David Joel Miller

Two David Joel Miller Books are available now!

Bumps on the Road of Life. Whether you struggle with anxiety, depression, low motivation, or addiction, you can recover. Bumps on the Road of Life is the story of how people get off track and how to get your life out of the ditch.

Casino Robbery is a novel about a man with PTSD who must cope with his symptoms to solve a mystery and create a new life.

For these and my upcoming books; please visit my Amazon Author Page – David Joel Miller

Want the latest blog posts as they publish? Subscribe to this blog.

Want the latest on news from recoveryland, the field of counseling, my writing projects, speaking and teaching? Please sign up for my newsletter at – Newsletter. I promise not to share your email or to send you spam, and you can unsubscribe at any time.

For more about David Joel Miller and my work in the areas of mental health, substance abuse, and Co-occurring disorders see my Facebook author’s page, davidjoelmillerwriter. A list of books I have read and can recommend is over at Recommended Books. If you are in the Fresno California area, information about my private practice is at counselorfresno.com.