Chapter 1 Flashcards
Drug
A drug is defined as any chemical that can affect living processes
Pharmacology:
Pharmacology can be defined as the study of drugs and their interactions with living systems
Therapeutics:
It is defined as the use of drugs to diagnose, prevent, or treat disease or to prevent pregnancy.
Therapeutics, also known as
pharmacotherapeutics,
Properties of an Ideal Drug: The Big Three
- Effectiveness
- Safety
- Selectivity
Effectiveness of Drug:
An effective drug is one that elicits the responses for which it is given.
The most important property a drug can have”
Effectiveness
Safety of drug:
A safe drug is defined as one that cannot produce harmful effects—even if administered in very high doses and for a very long time.
Selectivity of drug:
A selective drug is defined as one that elicits only the response for which it is given.
Additional Properties of An Ideal Drug: (4-10)
- Reversible Action:
- Predictability:
- Ease of Administration:
- Freedom from Drug Interactions:
- Low Cost:
- Chemical Stability:
- Possession of a Simple Generic Name:
Reversible Action:
That is, in most cases, we want drug actions to subside within an appropriate time.
Predictability:
we could know with certainty just how a given patient will respond.
Ease of Administration:
The route should be convenient,
And the number of doses per day should be low.
Ease of admission has two other benefits:
- It can enhance patient adherence, and
- It can decrease risk.
Patients are more likely to adhere to a dosing schedule that consists of one daily dose rather than several doses a day.
Furthermore, whenever skin integrity is broken, as is the case when drugs are given by injection, there is a risk of infection and injection-site pain and discomfort.
Freedom from Drug Interactions:
Because of the potential for interaction among drugs, when a patient is taking more than one agent, the possible impact of drug interactions must be considered.
An ideal drug would not interact with other agents.
Low Cost:
An ideal drug would be easy to afford.
Chemical Stability:
Some drugs lose effectiveness during storage.
Others that may be stable on the shelf can rapidly lose effectiveness when put into solution
Because of chemical instability, stocks of certain drugs must be periodically discarded. An ideal drug would retain its activity indefinitely.
Possession of a Simple Generic Name:
Generic names of drugs are usually complex, and so they may be difficult to remember and pronounce.
The Therapeutic Objective
The therapeutic objective of drug therapy is to provide maximum benefit with minimal harm.
Our ultimate concern when administering a drug
Is the intensity of the response
Administration of a drug includes:
drug dosage
route
timing of administration
All drugs are not taken or administered as prescribed, if dosage is too high:
The result may be toxicity if dosage is too high
All drugs are not taken or administered as prescribed, if dosage is too low:
The result may be treatment failure if the dosage is too low
Poor adherence
Sometimes patients do not take medications as prescribed.
To help minimize errors caused by poor adherence, you should
you should give patients complete instructions about their medication and how to take it.
Medication errors made by hospital staff may result in
may result in a drug being administered by the wrong route, in the wrong dose, or at the wrong time; the patient may even be given the wrong drug.
Pharmacokinetics:
Pharmacokinetic processes determine how much of an administered dose gets to its sites of action
Four major pharmacokinetic processes: the impact of the body on drugs
drug absorption
drug distribution
drug metabolism
drug excretion
Pharmacokinetic processes can be thought of as
These processes can be thought of as the impact of the body on drugs
Pharmacodynamics processes determine:
Once a drug has reached its sites of action, pharmacodynamic processes determine the nature and intensity of the response.
Pharmacodynamics can be thought of as
Pharmacodynamics can be thought of as the impact of drugs on the body.
What can influence pharmacodynamic processes?
Patient’s functional state can influence pharmacodynamic processes.
What can help determine the responses that a drug elicits?
Placebo effects also help determine the responses that a drug elicits.
