Introduction to Drugs and Behavior I Introduction a Behavior Action of reactions of an organism in response to external or internal stimuli b Drug A chemical substance that when taken alters the functioning of the body in same way excluding those nutrients considered to be related to normal functioning i Instrumental use Drug use for a specific purpose other than getting high 1 Ex Taking Tylenol to get rid of a headache ii Recreational use Drug use to achieve some pleasurable effect iii Drug abuse Drug taking behavior resulting in some form of physical mental or social a Psychoactive psychotropic drugs affect behavior by altering the function of the central impairment II Psychoactive Drugs nervous system i Two categories 1 Drugs of abuse recreational drugs 2 Psychotherapeutic drugs ii Four basic Principles 1 Drugs of abuse may have sound medical uses 2 Every drug has multiple effects 3 The size and the quality of a drug s effect depend on the amount taken 4 The effect of any psychoactive drug depends on the individual s history and expectations iii Terminology 1 Pharmacy Science of preparation of drugs 2 Pharmacology Study of the fate of drugs in the body and their actions on the 3 Psychopharmacology the study of the behavioral effects of drugs 4 Neuropharmacology the study of the effects of drugs on the nervous system ex body Brain III Categories of drugs grouped by medical use a Sedative hypnotics depressants i Behavioral effects sedate relax calm people At higher doses can induce sleep hypnotic ii Examples alcohol barbituates chloral hydrate iii Uses anti convulsants sedative muscle relaxant b Anxiolytics minor tranquilizers i Behavioral effects sedate relax calm people down ii Examples benzodiazepines valium Librium Xanax iii Uses acute anxiety anti convulsant muscle relaxant c Psychostimulants fatigue i Behavioral effects in low moderate doses increase alertness elevate mood reduce ii Examples amphetamine cocaine caffeine Ritalin iii Uses mostly used recreationally sometime narcolepsy and ADHD d Antipsychotics neuroleptics i Behavioral effects calm highly excited patients alleviate psychotic symptoms ii Example Haldol thorazine iii Uses Used to treat schizophrenia and mania in bipolar disorder e Antidepressants anti manics i Behavioral effects Elevate mood of depressed patients antidepressants and can stabilize mood in bipolar disorder anti manics ii Example lithium fluoxetine Prozac Zoloft iii Uses used to treat major depression and bipolar disorder f Hallucinogens psychedelics i Behavioral effects hallucinations altered states of consciousness psychotic like behavior ii Examples LSD mescaline shrooms PCP weed iii Uses Primary use is recreational religious ceremonies Some medical use cannabinoids anti nausea and vomiting g Anesthetics analgesics i Behavioral effects block or relieve pain produce euphoria ii Examples narcotics sedative hypnotics cocaine ketamine inhalants iii Uses significant medical and recreational use IV US Government Classification lumped in a Harrison Narcotic Act of 1914 prohibition of opium and opiate analogs other drugs later b Controlled Substances Act of 1970 modern foundation of the US drug enforcement policy i Regulation of manufacturing distributing and dispensing potentially dangerous drugs ii Drugs covered by this act are divided into 5 schedules and are referred to as controlled substances 1 Schedule I 2 Schedule II 3 Schedule III 4 Schedule IV 5 Schedule V a High potential for abuse no recognized legitimate medical use in the US i Examples heroin LSD marijuana a High potential for abuse currently accepted for medical use i Examples codeine morphine cocaine amphetamine a Potential for abuse less than I or II current medical use i Examples barbituates vicodin a Low abuse potential current medical use i Examples Valium Xanax a Lowest potential for abuse current medical use i Examples cough syrup 6 Sometimes Schedule VI inhalants Principles of Drug Action I How big of an effect will a drug have a Molecular structure of the drug b Concentration of the drug at the site of action depends on 1 dose administered and 2 rate of accumulation removal from site of action i Drug dose alone doesn t determine the effect of drug on body also depends on pharmacokinetics of the drug Pharmacokinetics and Pharmacodynamics II a Pharmacokinetics refers to the processes involved in the movement of drugs within biological systems with respect to absorption distribution metabolism and excretion i AKA the effect of the body on the drug b Pharmacodynamics the study of biochemical and physiological effects of drugs and their mechanism of action i AKA the effect of the drug on the body III Drug Dose and Dose Response Function a Drug s actions depend on the amount of drug available which in turn is dependent upon the dose of drug given b The usual way of discussing a drug s effects is in terms of the dose response function i Expresses the relationship between the dose administered and the response IV How are dose response functions determined observed a Groups of individuals are administered a different amount of a drug in question and the response is measured b Dose Response Cure graph comparing size of response to amount of drug c Plateaus at maximum effect d Therapeutic window the drug doses in which a therapeutic response is obtained e One drug can have different dose response curves depending on the effect being measured V General characteristics a Threshold dose minimally effective dose b Maximal response greatest degree of a given response that can be achieved with that drug c d LD50 lethal dose for half of the subjects tested i Death is considered a side effect ED50 effective dose for half of the subjects tested e f Side effects unintended effects that accompany therapeutic effects Therapeutic Index a measure of a drug s relative safety for use computed as the ratio of LD50 to ED50 i The greater the ratio the safer the drug optimally 100 ii Less than 10 is considered very unsafe g Efficacy Potency i Not all drugs in a given class are equally good at producing the same maximal effect efficacy 1 Efficacy how well a drug can produce a given effect ii Not all drugs produce the maximal effect at the same doses potency 1 Potency how much of a drug is needed to produce a given effect iii The less of a drug required to produce an effect the greater the drug s potency h Drug Interactions Potency efficacy of a drug can be altered presence of another drug Antagonism potency