Pharmacology: Drug Schedules, Administration, and Effects

A substance causing physiological effect other than nutrition

Drug

Drugs with no current medical use and have highest degree for potential abuse

Schedule 1

Drugs with some therapeutic purpose but high potential for abuse or dependency

Schedule 2

Drugs with moderate to low potential for dependency

Schedule 3

Drugs with low potential for abuse or dependency

Schedule 4

Drugs with lowest degree for potential abuse

Schedule 5

3 different ways to name a drug

chemical, generic, and trade/brand name

Factors needed for a drug to be considered bioequivalent of the original

within 20% of the original drug, must have same active ingredients (includes quality strength purity and stability), indications, and side effects

Phase 1 of clinical human trials

Safety assessment on small healthy population

Phase 2 of clinical human trials

Drug effectiveness on small population with disease

Phase 3 of clinical human trials

Therapeutic effects and toxicity on large population with disease (typically double-blind and placebo controlled)

Phase 4 of clinical human trials

Drug approved for public use with monitoring for problems or toxicity

What is off label prescribing?

practice of using an FDA approved drug for a purpose, dose, age group, or delivery method not officially approved

How the body absorbs, distributes, metabolizes, and eliminates a drug

pharmacokinetics

Analysis of what a drug does to the body

Pharmacodynamics

Study of harmful effects of chemicals

Toxicology

What are the five steps of the drug pathway

Administration, absorption, distribution, metabolism, elimination

Enteral administration

drugs administered anywhere along the GI tract (oral, buccal/sublingual, and rectal)

Parenteral Administration

Drugs given in routes other than digestive canal (IV, epidural, subcutaneous, ect.)

Topical Administration

direction application onto skin or associated membranes

Transdermal Administration

Intent of drug to be absorbed through skin, must penetrate and not degrade, slow and controlled release

Iontophoresis meaning

Electrical STIM

Phonophoresis meaning

ultrasound

What is bioavailability?

% of drug that makes it into systemic circulation from site of administration

What are the factors that affect absorption?

route of admin, rate of dissolution, surface area, blood flow, lipid solubility, drug properties, and physiological variables like gastric emptying

What are factors that affect distribution?

Tissue permeability, blood flow, binding to plasma proteins and sub cellar components, and anatomical barriers (BBB, BPB, BTB)

What is the blood brain barrier?

a filtering mechanism of the capillaries that carry blood to the brain and spinal cord tissue, blocking the passage of certain substances, CNS capillaries have tight junctions so only very lipid soluble drugs can enter

What is biotransformation?

changing of drug structure by enzymes primarily by the liver

What is first pass metabolism and how much does it usually decrease bioavailability?

a process where the concentration of an active drug is greatly reduced before it reaches the rest of the body's circulation, ~90%

Enzyme induction does what?

increases enzymatic capacity of liver, causing more metabolism and decreasing drug levels in blood

Enzyme inhibition does what?

Decreases enzymatic capacity of liver, causing less metabolism and increases drug levels in blood (grapefruit juice example)

What happens during renal excretion?

primary elimination method, lipophilic drugs reabsorbed in renal tubules and hydrophilic drugs are excreted in urine

What happens in biliary excretion?

secondary elimination method, secretion of bile acids to uptake of lipid soluble drugs which are eliminated in feces

What are the six factors impacting variation in drug response/metabolism?

genetics, disease, drug interactions, age, diet, and sex

How does age impact drug absorption?

may have lower absorption rates

How does age impact drug distribution?

hydrophilic drugs have lower volume of distribution due to less body water and lean mass, lipophilic drugs have increased volume of distribution due to increased fat stores

What is an agonist?

activates receptor

What is an antagonist

prevents/blocks activation

What is potency?

strength of a drug at a particular dose, amount required to produce an intended effect, concentration to produce 50% of max effect

what is efficacy?

max effect that can be achieved until no higher dose will produce further effect, determines clinical effectiveness

What is binding affinity?

how well the drug binds to a receptor

What is selectivity?

the number of receptors with which a drug interacts, leads to side effects

Explain therapeutic index

a quantitative measurement that compares the amount of a drug that causes toxicity to the amount that produces a desired therapeutic effect.

What is tolerance

same dose of drug produces less of an effect

What is sensitization?

same dose of drug produces more of an effect

What is a drugs half life?

Time it takes for 50% of the drug to be metabolized

teratogenicity meaning

causing fetal damage

What is polypharmacy

the simultaneous use of multiple drugs to treat a single ailment or condition

Adverse drug effect classification A

Augmented, dose related

Adverse drug effect classification B

bizarre, unpredictable and uncommon

Adverse drug effect classification C

chronic, only with prolonged period

Adverse drug effect classification D

delayed, remote from treatment (years later)

Adverse drug effect classification E

end of treatment, when stopped

Type 1 allergy

anaphylactic and most severe

Type 2 allergy

antigen adheres to target cell

Type 3 allergy

autoimmune reactions

Type 4 allergy

cell-mediated hypersensitivity