Introduction to Pharmacology Flashcards
What is an adverse drug reaction?
A response to a drug which is noxious and unintended, and which occurs at doses normally used in man
List 4 factors that may predispose patients to develop ADRS.
- Use of unlicensed and off-label prescribing
- Different pharmacokinetic and pharmacodynamics
- Overdosing
- Under-reporting: studies show that between 45%-92% of ADRs are identified
List 8 medications involved in adverse events requiring an ED visit.
- Insulin (most common)
- Antibiotics
- Anticoagulants
- Aspirin
- Ibuprofen
- Acetaminophen
- Hydrocodone
- Intentional overdoses
What is the true rate of adherence for appropriate drug use?
50%
What are the adherence rates if medication is dosed 1x/day? 2x/day? 3x/day?
1x/day = 73% 2x/day = 70% 3x/day = 52%
List 3 steps of the pre-clinical development process of a drug.
- Target Audience or Disease is identified
- Chemists generate compounds
- Pharmacologists perform testing on cells and animals
What are the 4 phases of the drug development process?
Phase I: Safety
Phase 2: Safety and Effectiveness
Phase 3: Safety and Effectiveness
Phase 4: Safety (Post-marketing Surveillance)
What takes place during phase 3 of the drug development process?
Phase 3: Safety and Effectiveness
Large studies are performed in different countries and populations to assess differences in drug metabolism
What takes place during phase 4 of the drug development process?
Post marketing surveillance: drug is being monitored after being released on the marked, for ARDS
One should not take a drug until it has been out on the market for at least ____ years.
2 years
True or False: Drug naming is consistent.
False
Based on source, chemistry, effects, and regulation
What class of drugs are named based on their pharmacotherapuetic action?
Anti-hypertensive drugs
What class of drugs are named based on their pharmacological action?
Diuretics
What class of drugs are named based on their molecular target?
Beta blockers
List the 4 process involved with the pharmacokinetics of a drug.
ADME
- Absorption
- Distribution
- Metabolized
- Elimination
List 6 things that influence the absorption of a drug.
- Physiochemical properties
- non-ionized are absorbed better, and acids are absorbed better in low pH (bases are absorbed better in higher pH)
- Lipid/water coefficient K: lipid soluble drugs are absorbed better
blood flow to the site of administration - Dosage Form: liquid faster than capsules
- Temperature: higher temps facilitate absorption
- Exercise
Drugs should be taken ____ exercise.
AFTER
The distribution of a drug depends on where _____ and presence of ______.
- Blood flows
2. Plasma proteins (albumin)
Why is there decreased drug distribution in patients with liver disease?
Drugs bound to albumin are no longer free to act at target organ.
In liver disease there is low albumin and thus greater free drug availability -leads to toxicity
What is volume of distribution? Equation?
Hypothetical concept to describe where the drug exists in the body
Vd = [dose]/[plasma concentration]
Describe the difference between a small vs large volume of distribution.
Small Vd : drug will be confined to the plasma compartment –stays mainly in blood stream (eg. heparin and warfarin).
Large Vd: drug can easily pass through the lipid membranes and are distributed widely around the body.
What is drug metabolism?
Modifies drug to facilitate excretion (filtered through glomerulus and the excreted in urine)
Most drugs are eliminated through the ______.
Kidneys
What is bioavailability? What type of drugs are 100% bioavailable?
% of given dose that reaches the systemic circulation.
Drugs given IV are 100% bioavailable
Enzyme _____ drugs increase the activity of the enzymes responsible for its metabolism.
Induction
Enzyme _____ drugs decrease the activity of the enzymes responsible for its metabolism.
Inhibition
What is first order elimination?
Rate of elimination is proportionate to the concentration (a constant % of drug is lost per unit of time)
Drugs with first-order elimination have a characteristic ____.
half-life of elimination (t1/2)
Time it takes for the concentration to decrease to half the value it had at the start of the dosing interval
What is zero order elimination?
A constant amount of drug is lost per unit time.
Any drug given through the mouth or into any part of the GI tract is considered ____.
Enteral
______ proteins allow the selective passage of specific ions when the ion channel is open.
Transmembrane spanning proteins
What is the difference between an agonist and a partial agonist?
- Agonist is a compound that binds to a receptor and produces a biological response
- Partial agonist produces a response but cannot produce 100% of the response even at a high dose
A _____ blocks or reverses the effect of agonists.
ANTAGONIST
List 3 things that decline with age that affect pharmacokinetics.
- Liver function
- Renal Clearance
- Maintenance dose should decrease
Why should the maintenance dose decrease with age?
Metabolizing drugs becomes more difficult with age, thus older individuals have more active drug in their blood stream, warranting for a decrease in dosage.
True or False: Medication should be taken AFTER exercise. Why or why not?
TRUE
Should be taken after exercise because the drug may not be metabolized effectively in the body if taken before exercise due to decrease blood flow to the kidney and liver.
List 2 areas that receive decreased blood flow during exercise.
Kidneys
Liver
What 3 areas receive increasing blood flow during exercise?
Heart
Skin
Muscles
What types of drugs should be given DURING exercise? Why?
Transdermal patches
Why?: increase in heat and blood flow to the skin will result in greater absorption of drugs given transdermally
In general expect ____ fold increase in plasma drug levels especially at temperatures higher than ____ degrees C.
1.5-2.5 fold increase
30 degrees C
Slowing of gastric emptying when exercise intensity reaches ____ VO2max—delays absorption. Why?
70%
Delays absorption because the drug is subjected to degradation from acid secondary to decreased blood flow to the digest tract during exercise.
Exercise reduces ____ which results in more rapid drug elimination.
Volume of distribution (Vd)
The clearance of ______ ratio drugs depends on blood flow so during exercise there is less metabolism.
High hepatic extraction
The clearance of ______ ratio drugs are not affected by change in blood flow during exercise but may be affected by level of fitness.
Low hepatic extraction
