Pharmacology test 1

The study of the effects of a particular chemical (drug) on a biological system

Any chemical, which acts on a biological system

The diagnosis, prevention or treatment of disease or for the prevention of pregnancy

• Plants, animals, minerals, soils
• organic synthetic chemistry
• genetically engineered microbes and cells

• selectivity of action (does a specific task)
• reversibility of action (biotransforms from an active to an inactive form of the drug)
• certain degree of potency (related to drug's affinity for a receptor)
• ability to interact chemically (must be able to travel to receptor site)

• regulates labeling and packaging of drug products
• establishes standards for purity and strength
• oversees quality control of manufacturing facilities
• determines drugs to be marketed in the U.S. after considering safety, efficacy, physical & chemical data
• determines what drugs are sold by prescription and which are OTC
• regulates advertising and labeling of prescription drugs

• Branch of the Dept. of Justice
• determines degree of control for substances with abuse potential
• enforces controlled substances act

• enforces consumer protection laws
• regulates marketing practices and advertising on foods, nonprescription drugs, dietary supplements and products promising health benefits.

• regulates manufacturing, distribution and dispensing of controlled substances.
• Established 5 schedules of controlled substances according to their abuse potential.
• Established requirements for prescribing controlled substances

Schedule 1

• Schedule 2.  
• In case of an emergency one can be called in.

Schedules 2-4

Schedule 5

Schedule 2

17 years

Only after the patent expires

chemical make-up/molecular structure of the drug

• The 'official' name given the drug
• this name is not capitalized

• This is the brand name/proprietary name
• Name given by drug manufacturer

drugs that produce similar concentrations in the blood and tissues

drugs that meet the same chemical and physical standards required by the FDA

• If clinical trials of 2 drugs show equal therapeutic effects, they are therapeutically equivalent.
• Biologic and therapeutic equivalence are the same

identical amounts of the same active drug ingredient in the same dosage form and route of administration and meet the same standards for strength, purity, quality and identity.

• physiological availability of a given amount of a drug.  
• Regardless of the route of administration, usually only a fraction of unchanged drug reaches the systemic circulation

They should get to the target tissue and act equally

• Prescription (legend)
• OTC
• Combination- multiple drugs in a single dose

with a prescription

Pharmacodynamics

• How a drug exerts its effects
• This occurs at the molecular level and is the event that occurs when the drug attaches to the receptor site

clinically desirable action of a drug

True

• What the body does to the drug
• sequence of events, which influences a drug's ability to reach the receptor in sufficient quantity and for sufficient duration of time to exert its desired effect

• Pharmacokinetics- what the body does to a drug
• Pharmacodynamics- what the drug does to the body

specialized area on a call or w/in a cell where a drug acts to initiate a series of biochemical and physiologic effects

hundreds

One

• occurs between atoms w/ opposite charges
• weak bonds and easily reversed

• bonds among hydrogen atoms and other molecules.
• Weaker than ionic bonds

• sharing of electrons by 2 atoms
• strongest type of bond
• often irreversible

relatively weak electric forces that attract neutral molecules to one another

a drug that has an affinity for a receptor site and binds to it, producing an effect

• drug that has an affinity for a receptor site and binds to it but produces no effect
• competitively blocks the effect of an agonist

the force of attraction of a molecule to a receptor site

The ability of an agonist to interact w/ a receptor and initiate a response

• Binds and activates a given receptor, but has only partial efficacy at the receptor relative to a full agonist.
• May inhibit the action of an agonist when given concurrently

• maximum intensity of response
• administering more of a drug will not increae efficacy, but can increase probability of adverse reactions

• relationship between the dose administered and the effect obtained
• as the dose of a drug increases (x-axis), the percentage of maximum response rises (y-axis) until increasing the dose further produces no increase in the percentage of response

the dose of a drug at which additional doses would produce no further beneficial effect

the lowest dose of a drug that will produce a measurable response

comparing drugs according to their potency and efficacy

• the amount of a drug needed to produce a response
• the more potent a drug, the less needed to produce a response

• Potency- related to affinity of a drug to its receptor
• Efficacy- related to intrinsic activity of that drug on e a drug receptor complex is formed.

• Dose of the drug required to produce the desired clinical effect in 50% of test animals.  
• Written as ED50

• Dose of the drug required to produce death in 50% of test animals.
• Written as LD50

• ratio of the median lethal dose to the median effective dose.
• Greater the TI, the safer the drug

at least 10 is considered safe

• Drug placed directly into GI Tract.
• Oral or rectal

• Drug bypasses GI tract
• injections, inhalation, and topical administration

• safest because absorption is slow
• least expensive
• good client acceptance
• allergic reactions less likely to occur

• patient compliance is essential
• nausea/vomiting side effects
• slower onset (usually at least an hour)
• blood levels less predictable

• Advantages-
• No GI upset
• can be used on unconscious patient
• Disadvantages-
• poor and irregular absorption
• poor patient acceptance

• Advantages-
• shortest onset of action (bypasses absorption, causing immediate effect)
• most predictable route
• best route for emergency situation
• Disadvantages-
• most dangerous form of drug administration
• potential for reactions at site of injection

• Advantages-
• absorption rapid and uniform
• Disadvantages-
• can be painful

Advantages-

• absorption is uniform
• Disadvantages-
• absorption is fairly slow

• Advantages-
• rapid onset
• Disadvantages-
• difficult to monitor doses
• Some gases irritating to respiratory tract

subcutaneous

no

• injection that penetrates only the top layers of the skin
• example: TB skin test

• Subcutaneous: dental anesthetic injections
• Topical: topic anesthetics used prior to injections. 
• Topical: locally delivered antimicrobials Ex: arestin, atridox, periochip
• Inhalation: nitrous oxide/oxygen conscious sedation
• Enteral: antibiotics for pre-med or infection, pain medication, anti-anxiety medication

• all drugs taken orally must pass through the liver via hepatic portal vein prior to reaching general circulation.
• The liver metabolizes drugs, sometimes to such ane xtent that only a small amount of active drug emerges from the liver into the circulatory system
• The first pass through the liver can greatly reduce the bioavailability of the drug

• Absorption
• Distribution- including to the site of action, where interaction with the receptor evokes a response
• Biotransformation- also called metabolism or detoxification
• Elimination

• process by which drug molecules are transferred from the site of administration to the circulating fluids.
• requires the drug to pass through biologic membranes

it determines when and how much of a drug becomes pharmacologically available to exert its action

• molecular size
• lipid solubility
• degree of ionization

nonpolar (nonionized), lipid-soluble

Polar (ionized), water-soluble (hydrophilic)

• passage of small, water-soluble substances through small pores in cell membranes
• most drug molecules are too large to pass through biological membranes by this process

• movement of a drug from an area of high concentration (blood stream) to an area with lower concentration (cell)
• diffusion will continue until concentration gradient has been eliminated
• passive diffusion does not require energy as compared w/ active transport

nonionized lipid-soluble

• A drug forms a complex w/ a component of the cell membrane
• the drug complex is then carried through the membrane, the drug is released and the carrier returns to its original position

• Movement of a drug from an area of low concentration to an area of higher concentration.
• This activity requires energy

through facilitated diffusion and/or active transport

• degree of ionization
• degree of lipid solubility
• presence or absence of food (if administered enterally)
• protein binding
• patient compliance with taking medication
• age
• gender
• genetic variations
• placebo effects
• other disease states
• interaction w/ food, minerals, other drugs

• less ionized (charged), more absorbed
• more lipid-soluble more readily absorbed

upper part of duodenum or small intestine

pH at which a drug is 50% ionized and 50% nonionized.

• Some drugs travel by binding to protein (albumin) receptors
• Some drugs bind to tissue, which can cause chemical effects

the drug will not produce the desired effect

toxic symptoms may develop

small, highly lipophilic (fat-loving) molecules

not a true barrier, but a selective gatekeeper

Liver

• drugs chemical structure is modified through oxidation, reduction or hydrolysis
• oxidative metabolism by the hepatic microsomal cytochrome P450 (CYP45) enzyme system is the primary method of drug metabolism
• a lipid-soluble drug is changed to a more polar (ionized) and more hydrophilic (water-soluble) metabolite so it is more easily excreted
• Drug interactions involving the cytochrome P450 system are common

molecules on the drug or metabolite from Phase 1 are conjugated (linked) with highly water-soluble compounds such as glucuronic acid to make a more water-soluble product

• individual differences in metabolic rate (genetic polymorphism)
• age
• liver disease
• pulmonary disease (inhaled drugs)
• endocrine dysfunction
• drug interactions
• cigarette smokers (may need more of a particular drug)
• food interactions

• Kidneys
• alcohol is partially excreted from the lungs

lungs

aspirin, phenytoin, ampicillin, diazepam, penicillin VK and phenobarbital

gingival crevicular fluid

• prescriber's name, address and phone #
• date of prescription
• patient's name, address, age and weight

• Rx: drug name and strength
• Disp: quantity to be dispensed
• Sig: directions for use

prescriber's signature, DEA #, refill info

1000 grams

1000 mg

1000?

1 ml

• Schedule 2
• must have written prescription
• can call in only in case of emergency
• no refills

• Schedule 3
• written or oral prescription allowed
• may refill five times w/in 6 months

fluoride, fluoride varnish, antimicrobial solutions for mouth rinsing or resorbable antimicrobial agents

no drug ever exerts a single action

• Very young
• Very old
• they organ functions are either not fully developed or progressively declining

• associated with the administration of therapeutic dosages of a drug
• usually predictable and avoidable
• responsible for most ADEs

• not dependent upon dosage
• rarely predictable or avoidable
• include hypersensitivity/allergic responses
• may be idiosyncratic (genetically related abnormal drug response)

• Cytotoxic reactions: causes by formation of unstable or reactive metabolites following biotransformation.  Related to abnormal metabolism and/or excretion
• Drug-drug interactions: drugs administered simultaneously may interact w/ each other to cause an unintended response.  (response may be pharmacologic, physiologic, chemical or may cause a receptor alteration)
• Drug-food interactions: some drugs are incompatible w/ foods when taken simultaneously.  Adverse reactions may interfere w/ absorption, metabolism or excretion
• Drug-disease interactions: drug prescribed for the treatment of one disease or condition may have an adverse effect on a different medical condition

• acetaminophen (APAP)
• pepole often overdose on this drug because it is contained in so many OTC formulations

• idiosyncratic
• allergic/immunologic reactions
• oncogenic effects- related to causing malignancy
• teratogenic effects- drug-induced damage that occurs to the developing fetus

• hyporeactive
• hyperreactive

drug produces its usual effect at an unexpectedly high dose, the patient is said to be hyporeactive

if a drug produces its effect at an unexpectedly low dosage the patient is said to be hyperreactive

the rapid development of tolerance to a drug