The Actions of Drugs - Class Notes

The Actions of Drugs Names of Drugs • Chemical name - gives a compiete chemical description of tue molecure "derived from the rules of organic chemistry for naming any compound • generic names - official or legal name of drugs - listed in the United States Pharmacopolia or USe - example: ampnetamine - Cannot be trademarked • brand name * spectic drug or formulation trademarked by manufacturers - patented drugs can be manufactured and sold for 20 years without direct Competition by the companies that discovered and patented them - example: Vyvanse, or lisdexamietamine dimesyiate • ex: sentraline - trade name: zoloft - Class: sevective Serotonin reuptake Innibitor antidepressant - Formula: CoHoCIeN • ex: lisdexamfetamine - trade name: Vyvance - Class: psychoactive - Chemical name: lisclexamfetamine dimesylare - formula: Cis His NIO Categories of Drugs • Simulants produce wakefulness and a sense of energy and well-being • depressants Slow nervous system actvity • opiods or narcotics produce a relaxed, dreamlike state • hallucinogens produce altered perceptions * psychotherapeutic drugs are prescribed by pipicians for the control ot mental disorders • Some drugs belong to muttiple caregories - ex: marivana and nicotine Drug Identification • prysicians can tell from appearance of the drug the exact drugard dose • The physician's desk reference or POK incides photographs of legally manufactured pharmaceuticals • ilegal drugs are sometimes marked, packaged, or labeled in an identifiable way - ex: momA • drugs can also be tested and identitied through chemical analyses Types of Drug Effects • nonspecific effects - derive from the useis unique background and particular perceptions of the environment - also called placebo ettects, because they can be produced by an inactive chemical that in treating pain and depression - important in treating pain and depression • Specific effects - depend on the presence of a chemical at certain Concentrations in the target tissue Double- Blind Procedure • test for the effectiveness of a new drug • neither the experimental participants nor the researchers know whether a Subject is receiving a placebo or an experimentas drug "the blinding Code is "broken" after the drug trial is over Dose- Response RelationShips • dose- response curve *grapn depicting the relationship between a rarge of drug doses and the resutting drug effects • threshold - the lowest dose at which an effect is observed • different dose resporse curves can be created for different drug effects - Some resporse suprems have higher thresholds - Some drugs haue an all-er-none close resporse retariorship Estimating the Safety Margin • Safety margin - difierence between the dose that produces the desired therapeute effect in most patients and the lowest dose that produces an unacceptable toxic reaction • potency - amount of a drug required to produce a particular effect • Side effects - unintended effects that accompany tuerapeutic effects • effective dose * dose of a drug that produces a meaninghul ettect in some percentage of rest subiects - EDro is the effective dose for half the arimals in a drug test • lethal dose - dose of a drug that has a lethal effect in some percentoge of test sublects - LDso is the lethal dose for half of the animal in a drug test • therapeutic index - defined as LD so divided by EDso - Should always be greater than one • most drugs have an LD, well above the EDas level Time- Dependent Factors • the time course of a drugs effect depends on: - how the drug is administered - how rapidly the drug is absorbed * Ipid Solubility affects the extent to unich a psychoactive drug dissolves in oils and fats " how the drug is eliminated from the body • drug eftects can be prolonged by taking adolitional doses at specific hme intervals * intervals vary from one drug to another - taking multiple doses too close together will increase the maximum blood level with eoch dose, wnich can result in cumulative effecks Routes of Administration- • oral administration • insuffiation • intravenous injection • Subcutaneous and intramuscular injection • inhalation Oral Administration absorption from the gastrointestinal tract is the most complicated way to enter the bloodstream -drugs must withstand digestive processes and not be deactivated by food before they are absorbed drugs must then pass through the cells lining the gastrointestinal tract and into the blood capillaries *only lipid-soluble and very small water soluble molecules are readily absorbed into the capillaries "drugs then pass through the liver * very little may get into circulation if they get metabolized rapidly Insufflation •onset of effects is faster than it is for oral administration - absorption through mucous membranes into the bloodstream occurs rapidly, bypassing the liver drawback associated with intranasal Septal region drug use includes nasal necrosis, or death of cells in the Intravenous Injection • drug is delivered directly into the bloodstream - results in a rapid onset of its effects than dose with oral administration or with other means of injection -irritating material may be injected this way, because blood vessel waus are relatively insensitive high concentrations can be delivered • risks veins may become damaged over time blood-borne diseases spread easily