NCM 106 - Pharmacology Tranes Preliminary Exam PDF

NCM 106 - PHARMACOLOGY Substances applied for therapeutic purposes fall into WEEK 1: one of the following three 1.1. FUNDAMENTAL CONCEPTS OF general categories: PHARMACOLOGY...

NCM 106 - PHARMACOLOGY Substances applied for therapeutic purposes fall into WEEK 1: one of the following three 1.1. FUNDAMENTAL CONCEPTS OF general categories: PHARMACOLOGY - Drugs or medications - Biologics DRUG DEFINITIONS AND - Complementary and CLASSIFICATION alternative medicines PHARMACOLOGY (CAM) therapies - came from the Greek words: 1. DRUGS - pharmakon (medicine) - A chemical agent capable - logos (study) of producing biologic - defined as the study of responses within the medicine. body - These may be desirable ❖ Pharmacology is an expansive (therapeutic) or subject ranging from undesirable (adverse). understanding how drugs are - After a drug is administered, to where they administered it is called a travel in the body, to the actual medication. responses produced. ❖ More than 10, 000 brand-name 2. BIOLOGICS drugs, generic drugs, and - Agents naturally combination drugs are currently produced in animal cells, available. by microorganisms, or ❖ Drugs can improve quality of life, the body itself. but can have devastating Examples are: consequences if it is not used - Hormones properly. - Monoclonal antibodies THERAPEUTICS - Natural blood - The branch of medicine products and concerned with the prevention of components disease and treatment of - Interferons suffering. - Vaccines 3. COMPLEMENTARY AND PHARMACOTHERAPY ALTERNATIVE MEDICINE - or pharmacotherapeutics is the (CAM) THERAPIES application of drugs for the - Involves natural plant purpose of disease prevention extracts, herbs, vitamins, and the treatment of suffering. minerals, dietary supplements, and many techniques considered by  some to be Aluminum - to decrease gastric unconventional. acidity. - Such therapies include Fluorine - prevention of dental manipulative and cavities. body-based practices Gold - treatment of rheumatoid such as acupuncture, arthritis. hypnosis, biofeedback Iron - treatment of iron and massage. deficiency anemia. SOURCES OF DRUGS SYNTHETIC SOURCES 1. NATURAL SOURCES - Uses genetic engineering to alter - plants, animals, or inorganic bacteria to produce chemicals compounds. that are therapeutic and - to become a drug, a chemical effective. must have a demonstrated - Aspirin, Oral Antidiabetics, therapeutic value or efficacy Antihistamines, Paracetamol, without severe toxicity or Thiazide Diuretics General and damaging properties. Local Anesthetics. PLANTS SOURCES OF DRUG INFORMATION - Digitalis products are used to DRUG LABELS treat cardiac disorders and - It contains specific information various opiates used for sedation that identifies a specific drug. are still derived from plants. - It identifies the brand and ANIMALS generic names for the drug, the - used to replace human drug dosage, the expiration date, chemicals that fail to be and special drug warnings. produced because of disease or - Some indicate the route and genetic problems. dose for administration. - Insulin for treating diabetes was PACKAGE INSERTS obtained exclusively from the - contains all of the chemical and pancreas of cows and pigs. study information that led to the - Thyroid drugs and growth drug’s approval. hormone preparations also may REFERENCE BOOKS be obtained from animal thyroid - The Physician’s Drug and hypothalamic tissues. Reference (PDR) is a INORGANIC COMPOUNDS compilation of the package insert - salts of various chemical information from drugs along elements can have therapeutic with some drug advertising. effects in the human body. JOURNALS - The American Journal of Nursing. INTERNET INFORMATION DRUG REGULATIONS AND RESPIRATORY STANDARDS - inhalation - The archives of drug regulatory SUBCUTANEOUS agencies are filled with examples of - subcutaneous tissue early medicines. TOPICAL Rattlesnake oil for rheumatism’ - through the skin Epilepsy treatment for spasms, hysteria and alcoholism PHARMACODYNAMICS Fat reducers for a slender, - pharmako; medicine healthy figure. - Dynamics; change - Refers to how a medicine PHARMACOPOEIA changes the body - A medical reference - Concerned with the mechanisms summarizing standards of drug of drug action and the purity, strength and directions for relationship between drug synthesis. concentration and responses in - US Pharmacopoeia (USP), the body. established in 1820. - Pharmaceutical ingredients HOW DRUG WORKS IN 4 WAYS came from the National 1. To replace or act as substitutes Formulary for missing chemicals - In 1975, they merged. 2. To increase or stimulate certain cellular activities HOW DRUGS ARE ADMINISTERED? 3. To depress or sloe cellular BUCCALLY activities - in the pouch between the cheek 4. To interfere with the functioning and gum of foreign cells, such as invading SUBLINGUALLY microorganisms. - under the tongue TRANSLINGUAL RECEPTOR SITES - on the tongue - where they act at specific areas on cell GASTRIC membranes called receptor sites. - direct into the GI system - react with certain chemicals to cause INTRADERMAL an effect within the cell. - into the skin INTRAMUSCULAR DRUG-ENZYME INTERACTIONS - into the muscle - works in a cascade function with one INTRAVENOUS enzyme activating another, and then that - into the veins enzyme activating another, until cellular ORAL reaction occurs. - through swallowing - if one step is blocked, normal cell RECTAL AND VAGINAL function is disrupted - suppositories SELECTIVE TOXICITY tissues, until it reaches systemic - The ability of a drug to attach circulation. only those systems found in - On a cellular level, drugs are foreign cells. absorbed by several means — - Penicillin, an antibiotic used to primarily through active or treat bacterial infections, has passive transport. selective toxicity. It affects an enzyme that causes bacterial cell THE LAZY WAY death. - Passive transport requires NO cellular energy because diffusion 1.2. PHARMACOKINETICS allows the drug to move from an area to higher concentration to PHARMACOKINETICS one of lower concentration. - the study of how the body reacts to the - Small molecules diffuse across presence of the drug. membranes and stops when - Kinetics refers to movement. drug concentration on both sides - Deals with a drug’s actions as it moves of the membrane is equal. through the body. - The term pharmacokinetics is derived USING MUSCLE from the ancient Greek words: - Active transport requires pharmakon - drug cellular energy to move the drug kinetikos - putting in motion from an area of lower - from the moment that a drug enters the concentration to one of higher body, the body recognizes it and concentration. processes it in a unique way, according - Absorbs electrolytes, such as to the individual characteristics of the sodium and potassium, as well drug. as some drugs such as levodopa. THE LADME SCHEME L = LIBERATION TAKING A BITE - The release of the drug from its - Pinocytosis is a unique form of dosage form. active transport that occurs when - Released from the formulation it a cell engulfs a drug particle is delivered in. - Pinocytosis is commonly - This must occur before the drug employed to transport fat-soluble can be absorbed into the body. vitamins. (A, D, E & K). A = ABSORPTION - The movement of drugs from the WATCH THE SPEED LIMIT site of administration to blood - If only a few cells separate the circulation. active drug from the systemic - Covers a drug’s progress from circulation, absorption will occur the time it’s administered, rapidly and the drug will quickly through its passage to the reach therapeutic levels in the body.  - Typically, absorption occurs active drug release into the within seconds or minutes when systemic circulation. a drug is administered - Therefore, higher drug dosages sublingually, IV, or by inhalation. must be administered to achieve the desired effect. NOT SO FAST - Absorption occurs at a slower MORE BLOOD, MORE ABSORPTION rate when drugs are - Increased blood flow to an administered by the oral, IM, or absorption site improves drug subQ routes because the absorption. More rapid complex membrane systems of absorption leads to a quicker GI mucosal layers, muscle, and onset of drug action. skin delay drug passage. - Blood flows faster through the deltoid muscle than through the AT A SNAIL’S SPACE gluteal muscle, but the gluteal - At the lowest absorption rates, muscle can accommodate a drugs can take several hours or larger volume of drug than the days to reach peak concentration deltoid muscle. levels. A slow rate usually occurs with rectally administered or SLOWED BY PAIN AND STRESS sustained-release drugs. - This may be due to a change in blood flow, reduced movement NOT ENOUGH TIME through the GI tract, or gastric - Other factors can affect how retention triggered by the quickly a drug is absorbed. autonomic nervous system - For example, most absorption of response to pain. oral drugs occurs in the small intestine. HIGH FAT DOESN’T HELP - Surgically removed large - High-fat meals and solid foods sections of the small intestine. slow the rate at which contents leave the stomach and enter the LOOK TO THE LIVER intestines, delaying intestinal - Drugs absorbed by the small absorption of a drug. intestine are transported to the liver before being circulated to DOSAGE FORM FACTORS the rest of the body. - Drug formulation affects the drug - The liver may metabolize much absorption rate and the time of the drug before it enters the needed to reach peak blood circulation. This mechanism is concentration levels. referred to as the first-pass effect. TYPES OF ORAL MEDICATIONS - Liver metabolism may inactivate TABLET the drug; if so, the first-pass - powdered medicine pressed into effect lowers the amount of hard round pills.  CAPLET Blood flow - solid pills that are coated to Solubility make it easy to swallow them. Protein binding ENTERIC COATED TABLETS OR CAPLETS QUICK TO THE HEART - coated so they won’t dissolve in - After a drug has reached the the stomach and upset it. bloodstream, its distribution in CAPSULE the body depends on blood flow. - gelatin shells that hold The drug is quickly distributed to medicine. organs with a large supply of LOZENGE blood. These organs include the: - flat, round, candy-like pills that Heart dissolve in the mouth. Liver SYRUP Kidneys - medicines dissolved in concentrated liquid. LUCKY LIPIDS - The ability of a drug to cross a ABSORPTION INCREASE OR cell membrane depends on DECREASE? whether the drug is water or lipd - Combining one drug with another soluble. drug, or with food, can cause - Lipid soluble drugs easily cross interactions that increase or through cell membranes; decrease drug absorption, water-soluble drugs can’t. depending on the substances Lipid-soluble drugs can also involved. cross the blood-brain barrier and enter the brain. DRUG INTERACTIONS SYNERGISM VITAMINS - Combined action of two drugs. WATER SOLUBLE Examples: - Vitamin B group - Sulfa + trimethoprim = - Vitamin C better bacteria killer FAT SOLUBLE - Aspirin + warfarin = - Vitamin A spont. hemmorhage - Vitamin D - captopril + nitro = enh. - Vitamin E BP control in CHF. - Vitamin K D = DISTRIBUTION FREE TO WORK - The process by which a drug - As a drug travels through the diffuses or is transferred from body, it comes in contact with intravascular space to proteins such as the plasma extravascular space. Distribution protein albumin. of an absorbed drug within the - The drug can remain free or bind body depends on several factors. to the protein.  - The portion of a drug that’s CONDITIONAL CONSIDERATIONS bound to a protein is inactive - Certain diseases can reduce and can’t even exert a metabolism. These include liver therapeutic effect. diseases such as cirrhosis as - Only the free, or unbound, well as heart failure, which portion remains active or can reduces circulation to the liver. produce a therapeutic effect. Gene machine - Genetics allows some people to M = METABOLISM metabolize drugs rapidly and - The chemical conversion or others to metabolize them more transformation of drugs into slowly. compounds which are easier to Stress test eliminate. - Environment, too, can alter drug - Drug metabolism, or metabolism. biotransformation, is the process - ➔ For example, cigarette smoke by which the body changes a may affect the rate of drug from its dosage form to a - metabolism of some drugs; a more water-soluble form that can stressful situation or event, such then be excreted. as prolonged illness, surgery, or injury, can also change how a Drugs can be metabolized in several person metabolizes drugs. ways: The age game - Most drugs are metabolized into - ➔ Developmental changes can inactive metabolites which are also affect drug metabolism. then excreted. - ➔ For instance, infants have - Other drugs are converted to immature livers that reduce the active metabolites, which are rate of metabolism, and elderly capable of exerting their own patients experience a decline in pharmacologic action. liver size, blood flow, and - Some drugs can be administered enzyme production that also as inactive drugs, called slows metabolism. prodrugs, which don’t become - active until they’re metabolized. E = EXCRETION - Drugs are metabolized by - The elimination of unchanged enzymes in the liver. drug or metabolite from the - It can also occur in the plasma, body via renal, biliary, or kidneys, and membranes of the pulmonary processes. intestines. - ➔ Most drugs are excreted by - If the liver is not working right, a the kidneys and leave the body drug doesn’t get metabolized through urine. normally. - ➔ Drugs can also be excreted through the lungs, exocrine (sweat, salivary, or mammary)  glands, skin, and intestinal LADME processes can be divided tract. into 2 classes: 1. Drug Input HALF-LIFE = HALF THE DRUG 2. Drug Output - The time it takes for one-half of the drug to be eliminated by the BIOAVAILABILITY body. - The term commonly used to - Factors that affect a drug’s describe the rate and extent of halflife include its rate of drug input. absorption, metabolism, and - Drugs administered by excretion. intravenous routes exhibit - Knowing how long a drug essentially 100% remains in the body helps bioavailability. determine how frequently it should be administered. IV - 100% SUBLINGUAL - 100% IMPORTANT ROLES IN A DRUG’S ORAL/INHALATION - 5 -