Created by Madeline Luedke
about 8 years ago
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Question | Answer |
Pharmacology | The scientific study of the actions of drugs, and their effects on living organisms |
Neuropharmacology | drug-induced changes in the functioning of cells in the nervous system |
Psychopharmacology | Drug-induced changes in mood, thinking or behavior |
Neuropsychopharmacology | Identify substances that act on nervous system, to help alter behavior for hurt or disease |
Drug Actions | Refer to the biological changes or the specific molecular changes produces when a drug binds to particular target site or receptor |
Drug Effects | the widespread physiological or psychological changes that occur as a result of drug action |
Specific Drug Effects | based on physical and biochemical actions of drug at target site on the body |
Non-specific drug effects | not based on chemical action, but unique characteristics of person (previous drug experience, present mood, environment, expectation, attitudes) |
Bioavailability | the amount of drug in the blood that is free to bind at target sites and causes actions |
Pharmacokinetics | the dynamic other factors that contribute to drug action (absorption, distribution, elimination) |
Absorption | movement of drug from site of administration to blood circulation |
Drug Map | 1. Route of administration 2. Absorption/Distribution 3. Binding 4. Inactivation 5. Excretion |
Different routes of administration | 1. oral 2. intravenous 3. intramuscular 4. intraperitoneal 5. subcutaneous 6. inhalation 7. topical 8. transdermal |
Oral (PO) | • easy, painless • must dissolve in stomach fluid • be able to pass through stomach walls to blood • resist destruction by stomach fluids • most drugs are not fully absorbed until in small intestine |
First-pass metabolism (first-pass effect) | PO drugs goes to the liver before the blood which reduce the amount of bioavailability • PO drugs produce blood levels that are irregular, unpredictable, and rise slowly |
Intravenous (IV) | • placed directly into blood stream • Pros: rapid & accurate • Cons: easy to overdose |
Intramuscular (IM) | • into muscle •Pro: slower and even absorption (slower if in vegetable oil suspension) • Con: irritation at injection site |
Intraperitoneal (IP) | • into abdominal cavity • Pro: Rapid (less than IV) • Con: Rarely used in humans |
Subcutaneous (SC) | • inject below the skin • Pro: slow and steady absorbtion |
Inhalation | • inhaled directly into lungs • Pro: rapid • lungs have large surface area with capillaries, blood goes directly to brain (no liver first) • surpasses first-pass metabolism |
T | • applied to mucus membrane • provides local drug effect, but can go system wide |
Transdermal | • through skin • skin blocks water soluble drugs, but fat soluble can pass • Pro: controlled, sustained passage, at given rate |
phospholipids | complex lipid molecules • look like Y • single head is negatively charged & hydrophilic (likes water) • two tails are uncharged, fatty & hydrophobic (hates water) |
hydrophollic | • single head of phospholipid that likes water • touches intra and extra cellular fluids |
hydrophobic | • two-tail fatty ends stick together |
Lipid-soluble drugs | • can pass through membranes • move from high concentration to low |
passive diffusion | move from higher concentration to lower concentration |
concentration gradient | differences in concentration • the steeper the gradient, the faster the diffusion |
Ionization | Dissolve into charged ion particles when in water • ionized stuff doesn't pass through membranes easily |
pH scale and ionization | Strong acids: low numbers, ionize completely in water | battery acid weak acids: kinda ionize | tomatoes Neutral: 7 Weak Bases: kinda ionize | SLC Strong bases: high numbers, ionize completely completely in water | drain cleaner |
Weak | • tends to dissolve into charged ions • weak doesn't mean not concentrated • most drugs are weak acids/bases |
Environmental factors and Ionization | • depends on ionizeability of drug (pH) • pH of place drug is being dissolved in • same pH = less ionization • acid <3 base = baby ions • lack of charge means more lipid soluble so it can pass through into blood |
Ion trapping | drugs can't go back into blood |
Absorption Factors | 1. Rate: at which stomach empties into small intestine 2. Size: of person, dosages based on 18-65 at 150 lb 3. Sex: of person, women have more fat, less water volume = higher drug concentrations |
Blood Brain Barrier | • Protects blood-borne substances by dense network of blood vessels • "net" |
Blood flow and concentration | • most blood flow have higher concentration • heart, brain, kidneys, liver • brain gets 20% of blood that leaves the heart |
Cerebral Spinal Fluid (CSF) | • made by choroid plexus • fills "spaces" • cushions brain against injury • blood vessels pass through subarachnoid space |
Typical Capillaries | • Nutrients in/waste out • small openings (intercellular clefts) • big openings (fenestrations) • pinocytotic vesicles (transport stuff through/elevator) |
Intercellular Clefts | small openings in capillaries |
Fenestrations | big openings in capillaries |
Pinocytotic Vesicles | • like an elevator • transports stuff through |
Brain Capillaries | • Cleft closed with tight junctions • no fenestrations • rare pinocytotic vesicles • surrounded by glial feet of astrocytes |
Area Postrema | Chemical Trigger Zone (CTZ) | • in medulla of brain stem • detects toxic substances in blood • vomiting center |
Median Eminence | • of hypothalamus • has fenestrations that let hormones made in hypothalamus move to pituitary gland |
Placental Barrier | seperates blood circulation of pregnant mother and fetus • lipid-soluble drugs pass easily |
Drug Depots | reservoirs of drug at inactive sites which trigger no biological effects • plasma protein, muscle, fat |
Depot Binding | • drug binding at depot sites • displaced drug gets dumped back into circulation |
Biotransformation | metabolically transformed |
First-Order Kinetics | • elimination is exponential: constant faction of drug is removed from blood at each time interval |
Half-life | amount of time needed to remove 50% of drug in blood • after 6 half-lives the drug is gone |
Zero-Order Kinetics | • drug molecules cleared at constant rate, regardless of concentration • alcohol |
Microsomal Enzymes | • in the liver • most drugs metabolize through this |
Two kinds of biotransformation | 1. Phase 1, Nonsynthetic 2. Phase 2, Synthetic |
Phase 1, Nonsynthetic | • by oxidation • resulting metabolite is less lipid soluble and often less active |
Phase 2, Synthetic | • required combination of drug with another small molecule (gulcoronide, sulfate, or methyl group) • Resulting metabolite is less lipid soluble, always inactive |
Cytochrome P450 | • 30 enzymes in this family oxidize a majority of psychoactive drugs |
Notes on biotransformation | both create metabolites which are more water soluble and easier to excrete • metabolites are returned to the bloodstream • metabolites eliminated by kidneys or bile/feces |
Factors Influencing Drug Metabolism | • Can affect the magnitude and duration of drug effects • responsible for drug interactions, and individual responses 1. Enzyme Induction 2. Enzyme Inhibition 3. Drug Competition 4. Genetic Polymorphisms |
Enzyme Induction | repeated use increases liver enzymes = faster metabolism for that drug and all others that need that enzyme • tolerance & cross-tolerance |
Enzyme Inhibition | some drugs block enzymes = slower metabolism for that and all other drugs needing that enzyme |
Drug Competition | for same enzymes • can't metabolize both, so levels of one get out of control |
Genetic Polymorphisms | people vary in metabolism |
Acetaldehyde | metabolite of alcohol • effects 50% of Asians when this builds up |
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