Terminology of Drug Use, Reactions & Interactions

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  • 0:20 Drug Use, Reactions &…
  • 0:40 Drug Reactions
  • 2:20 Drug Interactions
  • 3:30 Drug Use
  • 4:35 Lesson Summary
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Lesson Transcript
Instructor: Artem Cheprasov

Artem has a doctor of veterinary medicine degree.

Do you read drug labels? Do you know why they exist? Drugs interact and react in odd ways, so it pays to read them and be safe. This lesson defines some drug reactions, interactions, and other terms.

Drug Use, Reactions, & Interactions

Did your mother ever warn you not to do something? Maybe she warned you because she knew it wasn't good for you even if it was okay for other kids or for another reason. And then, like almost any kid, you probably did do it and had a bad result, right? A mother knows best!

In the world of pharmacy and pharmacology, we also know what's best a lot of the time. Like when patients are warned to not do something, or not do something because they have a specific medical condition, and what'll happen if they do take a certain drug.

This lesson will cover important terms related to such drug use, drug reactions, and interactions.

Drug Reactions

Whenever you use a drug, there is the potential for an adverse drug reaction (ADR), which is simply a bad side effect. It's the undesirable effect that you may or may not experience when taking a drug to treat a problem. This is why warnings exist on labels to only take certain amounts of a drug, like two tablets, or for no longer than a certain period of time, like two weeks, to minimize the chances of bad side effects. An example of a side effect would be lethargy from a drug designed to treat a sinus infection.

Some adverse reactions are specifically called paradoxical reactions, reactions to a drug that are exactly the opposite of the intended effect. A case in point would be if a drug is supposed to make you mellow, but it actually makes you super excited. That's a paradoxical reaction.

Other kinds of reactions are idiosyncratic reactions, which are rare and unpredictable drug reactions that don't occur in most patients. These reactions can easily be life-threatening. For example, if an antibiotic, a drug that kills bacteria, is known to usually cause a few minor side effects in most people, yet it causes liver failure in one particular patient, then that would be an idiosyncratic drug reaction.

Drug reactions with the body can also lead to addictions. An addiction is a state of physical or psychological dependence on a behavior or substance, especially compulsive dependence, to the extent that such dependence leads to societal or personal harm. Pain relieving drugs, like opioids, have a high potential for addiction in people.

Drug Interactions

In addition to reacting with the body to produce addiction, paradoxical reactions, or side effects, drugs can also interact with one another in many different ways.

Two examples of terms related to this are drug interaction and potentiation. When we use the term drug interaction, we don't limit ourselves to the obvious interaction between two drugs. A drug interaction is a state, desirable or not, of a drug interacting with another agent, such as a drug or component in the diet. For instance, many drugs often poorly interact with alcohol, and you may find warning labels to avoid the consumption of alcohol a set time before or after taking a medication.

When some drugs interact with one another, they may potentiate one another. Potentiation is a kind of drug interaction where the effect of one drug is increased by another drug or agent, such as an herbal remedy. For example, some antihistamines, which are drugs that stop certain aspects of allergies, can be given with a painkiller to reduce the amount of the painkiller needed as its effect is increased thanks to the antihistamine.

Drug Use

Clearly, due to the interactions and reactions drugs undergo, it's important a person is compliant with the instructions given to them on the label or by the doctor.

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