Introduction To Pharmacology Flashcards
What is meant by therapeutic jungle?
Need to select the appropriate drug or drugs for a patient since there are so many out there
What’s the difference between and cardiologist drug selection and a family practitioner drug selection?
Cardiologists use a limited number of drugs and are therefore familiar with problems associated with drug selection, dosage schedules, side effects, etc.
Family practitioners have a more diverse patient population and are therefore challenged by the therapeutic jungle
Clinically, the initial molecular action of the drug in a patient cannot be detected. Instead, the molecular process initiates a cascade of events that produce an effect detectable by what?
1) Instruments, e.g. Measure blood pressure
2) Laboratory tests on body fluids or tissue samples
3) Direct observation of the patient by the physician
Pt has congestive heart failure. What do you give them?
Digitalis preparation
How does digitalis preparation help a patient with congestive heart failure?
1) specific binding of digitalis glycoside to cardiac membrane Na K ATPase
2) inhibition of Na K ATPase or sodium pump
3) increase in intracellular Na concentration
4) increase in intracellular Ca2+ by an effect on Na/Ca exchange
5) interaction of Ca2+ with troponin C and removal of tropomyosin inhibition
6) increase in myosin-actin interaction
7) increase in force of myocardial contraction
8) improve systemic circulation
9) reduction in signs and symptoms of heart failure
What are the effects of a drug when a patient’s kidney’s shut down?
The drug sticks with the pt longer, meaning that if you don’t reduce the dosage, you can overdose the patient
Large doses needed in some patients while others respond to normal or below normal levels
Patient-to-patient or biological variablity
In these certain situations, diseases that can prove difficult to diagnose, drug therapy is often initiated before lab results or physician reports are complete
Life-threatening situations
The status of the patient may change. What does this mean for your plan of action?
The drug, its amount, and the frequency of administration may need modification as the patient’s condition improves or worsens
What are the issues with using multiple drugs?
Out-patients may be taking 4-8 drugs, and some elderly take up to 12 drugs. The opportunity for drug interactions increases exponentially as the number of drugs taken increases
The choice of drug makes drug selection difficult, therefore, what does selection involve?
Experience and an element of experimentation
The study of the interaction of chemicals with living systems
Pharmacology
Substances that act on living systems at the chemical (molecular) level
Drugs
The molecular components of the body with which a drug interacts to bring about its effect
Drug receptors
The study of drugs used for the diagnosis, prevention, and treatment of disease
Medical pharmacology
The study of the undesirable effects of chemical agents on living systems; considered an area of pharmacology; deals with the action of industrial pollutants, natural organic and inorganic poisons, and other chemicals on species and ecosystems
Toxicology
Refers to the actions of a drug on the body, including receptor interaction, dose-response phenomena, and mechanisms of therapeutic and toxic action
Pharmacodynamics
Refers to the actions of the body on the drug, including absorption, distribution, metabolism and excretion; elimination of a drug may be achieved by metabolism or by excretion
Pharmacokinetics
The ratio of the dose of drug that produces toxicity in 50% of the population to the dose that produces a clinically desired or effective response in 50% of the population
Therapeutic Index (margin of safety of drug)
TD50
1) 10
2) 100
3) 3
ED50
1) 2
2) 10
3) 1
Which is safest?
2 (therapeutic index is 10, which is the highest of all of these)
TD50
1) 10
2) 100
3) 3
ED50
1) 2
2) 10
3) 1
Which is most harmful?
3 (therapeutic index is 3, which means that the patient only has to take 3 times the recommended dose of that drug to get toxicity)
For most drugs, the magnitude of the pharmacological response _____ as the concentration of the drug at the site of action _____.
- increases
- increases
Why does it take a few seconds for the administration of a drug to show effects?
It takes time to distribute and bind
Do we want to get to 100% max suppression?
No. It will cause other problems if you completely shut down the target. 90% is pretty good.
