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Clinical. Pharmacology Basics. What is Pharmacology?. Pharmacology: The study and description of drugs, their composition, actions, and effects. Definitions. Pharmacy : A licensed business involved in dispensing drugs. Dispensing :
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Clinical Pharmacology Basics
What is Pharmacology? • Pharmacology: The study and description of drugs, their composition, actions, and effects
Definitions • Pharmacy: A licensed business involved in dispensing drugs. • Dispensing: Compounding, packaging, labeling, and selling and/or delivering a drug in response to a prescription written by a qualified health provider • Pharmacokinetics Deals with the effects drugs have on people, including absorption, metabolism, distribution, and excretion • Toxicology Concerned with the adverse effects of drugs and chemicals used for therapeutic purposes • Clinical Pharmacology Study of how drugs work, how they interact with other drugs, and their therapeutic effects on diseases and disease processes
Drugs • Drug: A chemical substance that affects the processes of the mind or body Any chemical compound used in the diagnosis, treatment, or prevention of disease or other abnormal condition.
Drug Sources • Plants • From leaves, seeds, sap, stems, fruit, roots • Ex Willow tree extract used in aspirin • Animal Sources • Usually a source of hormones • Ex insulin from pigs, estrogen from horses • Minerals • Supplements and chemicals • Ex iron, milk of magnesia, lithium carbonate
Drug Sources • Semi-synthetic • Drug from a natural source is combined with a synthetically produced compound to alter the effect • Ex heroin is semi-synthetic variant of morphine • Synthetic • Drug completely formulated in the laboratory • Ex insulin, ibuprofen, diazepam (Valium)
Drug Names • A single drug can have up to four names • Chemical • Represents the exact formula • Ex N-(4-hydroxyphenyl) acetanamide is Tylenol • Generic • Official, nonproprietary name given by international body to ensure no two products have the same name • Always spelled in lowercase • Ex acetaminophen (Tylenol), tetracycline
Drug Names • Trade Name • Patented name chosen by a company for sales purposes • Patented compounds are protected for 20 years • Patented trade names are protected forever • Other companies can produce a drug after the patent on the compound runs out, but they cannot use the patented trade name • Pharmacists can replace a prescribed Brand name drug with the equivalent generic as long as the doctor has not indicated “no substitutions” • Ex Advil (ibuprofen), Tylenol (acetaminophen)
Drug Names con’t • Botanical Name • Refers to the natural substance that a drug is made of • Digitalis purpurea is the plant from which digitalis is derived
Dispensing Drugs • Two methods: • Prescription • Drugs defined by the federal government to be dangerous, powerful, or habit forming are only available by physician’s order • Correspond to NAPRA Schedule I • Pharmacist must have prescription from physician before it is filled
Dispensing Drugs con’t • Over-the-Counter (OTC) • Drugs that are considered safe to take without specific advice of a physician • 3 categories • Pharmacy Only: Restricted Access (Schedule II) • Pharmacy Only: Under Supervision (Schedule III) • Sold Anywhere: No Restrictions (Unscheduled)
Classification of Drugs • Classification of Drugs by Use • Therapeutic • Taken to relieve symptoms • Diagnostic • Used to perform diagnostic tests • Curative • Overcome a disease, infection, or other condition • Replacement • Taken to replace a hormone or other normally present substance that the human body can no longer produce • Prophylactic • Prevent a condition or to decrease the severity of a condition
Classification of Drugs • Classification by Scope of Action • Local • Drug is stored and produces an effect only at the site of application • Ex steroid creams to treat a rash • Systemic • Drug circulates through the bloodstream to produce a general effect • Ex most orally ingested drugs • Cumulative • Drug accumulates in the body faster than it can be metabolized or excreted and exerts a greater effect than the initial dose. • Can be harmful or beneficial • Ex some antibiotics
Classification of Drugs • Classification by Action or Function • Analgesic • Anesthetic (Local, Regional, General) • Antacid • Anxiolytic • Antibiotic (bactericidal, bacteriostatic) • Anticoagulant • Anticonvulsant
Classification of Drugs • Anti-depressant • Antihyperglycemic • Antidiarrheal • Anti-emetic • Antifungal • Antihistamine • Antihypertensive • Anti-inflammatory (NSAID)
Classification of Drugs • Antipyretic • Antitussive • Bronchodilator • Cathartic • Contraceptive • Decongestant • Diuretic • Emetic
Classification of Drugs • Hormone • Hypnotic • Miotic • Narcotic • Purgative
Drug Classification • Classification by route of transmission • Some drugs must be administered in a very specific form for them to act. Others come in different forms that can be used for different circumstances. • Ex Antibiotics can be given orally for normal treatment, but can also be injected intravenously for more rapid action
Routes of Transmission • Topical / Transdermal • Applied to a body surface or mucous membrane • May be local or systemic • Ex steroid cream to locally treat dermatitis, patch to deliver hormones, heart medication, motion sickness, etc • Ointment: emulsion of semisolid consistency having a petroleum or paraffin base • Lotion: active ingredients contained in a water base • Liniment: active ingredients contained in a liquid base, usually more oil than lotions
Routes of Transmission • Inhalation • Drugs administered into the airway to be absorbed through the mucous membranes of the respiratory system • Puffers or Metered Dose Inhalers (MDI’s) dispense a powder or nebulized liquid • Otic • Placed directly in the ear – usually drops • Often antibiotics used to treat ear infection
Routes of Transmission • Ophthalmic • Drops or ointments placed directly in the eye • Used to treat localized eye conditions • Nasal • Drugs sprayed or inhaled through the nostrils • Sprays are often used for localized effect • Ex Otrivin • Mostly decongestants, but also pain medication
Routes of Transmission • Sublingual or Buccal • Drugs placed under the tongue or between the cheek and the gum • Usually absorbed through mucous membranes – no swallowing • Quick acting • Used for nitroglycerine, Ativan (tranquilizer)
Routes of Transmission • Vaginal • Suppositories or creams to treat local infections • Creams or foams used in contraception • Rectal • Suppositories that dissolve at normal body temperature • Effect can be local or systemic • Ex suppository for hemorrhoids, nausea • Enemas used for diagnostic purposes
Routes of Transmission • Oral • Most common route of delivery • Comes in many forms • Pills: pressed, round, solid medication (AKA Tablet) • Enteric-coated: covered to prevent medication from dissolving until later in the GI tract (intestines) • Sustained Release: additives slow the action of the drug to ensure sustained action
Routes of Transmission • Oral con’t • Caplets: Oval-shaped solid medication, may be easier to swallow • Capsules: drug in powder or liquid form encased in a hard or soft shell (usually gelatin) – masks taste of drug, can be extended release • Liquid: easy to ingest • Suspension: small particles of medicine suspended in a liquid base • Emulsion: droplets of oil and water mixed together • Elixir: contains alcohol, sugar water and sometimes flavouring • Syrup: Similar to elixir, but no alcohol and thicker
Routes of Transmission • Parenteral • Administration by injection • Fastest, most accurate effect • Several ways to inject • Subcutaneous (SC) • Intradermal • Intramuscular (IM) • Z-track • Intravenous (IV)
Drug Effects • Therapeutic Action • The effect considered desirable • Side Effect • Two kinds: • Those that are expected to occur and are usually minor • Those that are detrimental to the health of the patient (may be fatal) • AKA Adverse Effects • Allergies • Different from side effects • Serious reaction such as chest pain, skin rash, anaphylaxis that is life threatening • Must also be aware of food allergies when prescribing medication
Factors that Influence a Drug’s Effect • Body Weight • Drug effects are often not about amount, but about proportion • Larger people need larger doses • Age • The elderly and young children process drugs differently due to differences in metabolism and excretion mechanism
Factors that Influence a Drug’s Effect • Time of Day • Food intake, normal body rhythms, level of activity all affect drug action • Some drugs need to be taken on a strict schedule • Some drugs should always be given at same time of day, some on a full stomach, some on an empty stomach • Certain foods should be avoided with certain drugs
Factors that Influence a Drug’s Effect • Gender • Men and women’s bodies process differently due to differences in muscle mass and hormone levels • Pregnancy is also a significant issue • Other medication • Physicians and pharmacists check for drug – drug interactions • Herbal medicines can also effect a drug’s action
Natural Health Products (NHPs) • Includes: • Vitamins and Minerals • Herbal remedies • Homeopathic medicines (HM) and Traditional medicines • Probiotics • Natural Health Products Regulations (2004) • To be sold, products must have a Product License • NPN – natural product number • DIN-HM – homeopathic medicine number • Manufacturers must have a Site License
Natural Health Products (NHPs) • Should be treated as drugs • Many have therapeutic effects • Many also have side, unpredictable and/or adverse effects • Can interact with other, prescribed medications • Encourage patients to bring/list natural health products when they tell the physician about other medications they are taking
Drug Resources • Compendium of Pharmaceuticals and Specialties (CPS) • Updated list of drugs, with information on action, indications, contraindications, and side effects • Internet • Be careful that you get information from reputable sources!