Week 1 - Introduction to Pharmacology Flashcards
Why is pharmacology important to dental hygienists?
- Obtaining/reviewing HH and assessing all medication the client is taking currently.
- Understand the administration of drugs in the office.
- Handling an emergency situation.
- Client care
- Planning appointments
What is Pharmacology?
“Pharmacon” = drugs, medicine, poison
“logos” = science
- Study of drugs & their interactions with living organisms.
- Includes a drug’s: Composition, Uses, Effects
What are the 5 major disciplines of pharmacology?
- Pharmacodynamics,
- Pharmacokinetics,
- Pharmacotherapeutics,
- Pharmacogenetics
- Toxicology
What is Pharmacodynamics?
- Study of the effects of drugs on the body.
- “What the drug does to the body.”
- i.e. local anesthetic interferes with nerve transmission.
What is Pharmacokinetics?
- Study of how a drug moves through the body (enters & exits the blood and tissues)
- “What the body does to the drug”
What is Pharmacotherapeutics?
- Study of disease through administration of drugs.
- aka. drug therapy
What is Pharmacogenetics?
- aka. pharmacogenomics
- the study of genetic factors that influence the way an organism responds to a drug.
- How the genetic makeup of an individual affects his response to drugs.
- e.g. isoniazid in treatment of TB.
What is toxicology?
- Study of the harmful effects of drugs on living cells, tissues and organisms.
What are the medical uses of drugs?
- Preventive use
- Diagnostic use
- Therapeutic use
Describe PREVENTIVE use of drugs.
- Used to prevent occurrence of a disease/condition.
- Administration for this purpose = prophylaxis
- E.g. contraceptives to prevent pregnancy, vaccinations
Describe DIAGNOSTIC use of drugs.
- Used to provide evidence of a disease process.
- E.g. radiopaque contrast dues used during X-ray procedures.
Describe THERAPEUTIC use of drugs.
- Used to control, improve or cure a disease/condition.
- E.g. antibiotics for a bacterial infection.
What is a drug?
- Any chemical substance that affects biologic systems.
- Drugs used to treat disease are called medicine(s)
- Can be organic, inorganic, bio-engineered.
What are the different sources of drugs?
- Plants
- Animals
- Minerals
- Synthetic
- Bioengineering
Describe PLANT drug source.
- E.g. Poppy plant
- Opium is the principal precursor of narcotic and analgesic opiates such as morphine, heroin, and codeine.
- E.g. Willow bark
- Acetylsalicylic acid, the active ingredient in aspirin
Describe ANIMALS drug source.
- Snake venom = contains a protein that may help prevent breast cancer from spreading to other body sites.
Describe MINERALS drug source.
- Come from Earth and are used as they naturally occur.
- E.g. Gold may be used to treat severe arthritis.
Describe SYNTHETIC drug source.
- Stynethic sources = “laboratory-made”
- Designer drugs = Molly (Ecstasy) (3,4,Methylenedioxymethamphetaime; MDMA)
Describe BIOENGINEERING drug source.
- E.g. Antimalaria Drug By combining genes from three separate organisms into a single bacterial factory gives them the ability to make artemisinin (drug which kills malaria) quickly.
- Many vaccines
Drugs have at least three names:
- Chemical name
- Generic name
- Trade/Brand name
CHEMICAL drug name
- Used when drug is first discovered
- Identified by the drugs atomic or molecular structure
- Usually long and difficult to pronounce and remember
- E.g. N-(4-hydroxyphenyl) acetamide
GENERIC drug name
- Name before drug is approved to be marketed
- “Official name”
- Each drug only has one generic name
- Not capitalized
- May be used by any drug manufacturer.
- e.g. acetaminophen
TRADE/BRAND name
- Developed by the manufacturer
- Registered as trademark
- Always CAPITALIZED
- E.g. Tylenol
Explain the NUMBERING SYSTEM for naming drugs.
- Found in the trade name of some drugs.
- Number refers to amount of one component to differentiate it from an almost identical product.
- Examples: Tylenol 1, Tylenol 2, Tylenol 3. (Each has an increasing amount of codeine)
Explain CHEMICAL (pharmaceutical) EQUIVALENCE.
- When two formulations of a drug meet the chemical and physical standards established by a regulatory agency.
- They have to meet 3 criteria:
1) Contain the same active ingredients
2) Are the same dosage form and route of administration
3) Are identical in strength or concentration
Explain BIOLOGICAL (bioequivalence) EQUIVALENCE.
- When one company develops a generic version of another company’s brand-name drug, it is not enough for them to simply reduce the brand-name drug’s chemical structure or to buy the active ingredient from a chemical manufacturer.
- The manufacturer has to prove that the generic version is bioequivalent: it releases its active ingredient (the drug) into the bloodstream at the same speed and the same amounts as the original drug.
Explain THERAPEUTICAL EQUIVALENCE.
- When two formulations of a drug produce the same clinical effect and safety profile.
- Only occurs if they are both chemical and bioequivalent. TE = B + C
Regulation
The National Food and Drugs Act, created by parliament, sets out broad legal principles. It authorizes regulations to be followed: Food and Drug Regulations.
The NFDA classifies drugs as:
- Prescription and non-prescription pharmaceuticals
- Biologically-derived products like vaccines, blood-derived products, and products produced through biotechnology.
- Tissue and organs
- Disinfectants
- Radiopharmaceuticals
Vitamins and mineral supplements and therapeutic herbal products are:
- also considered by the Food and Drugs Act, but are regulated as natural health products under the Natural Health Products Regulations and not as drugs under Food and Drug Regulations.
Health Canada is responsible for:
establishing standards for drugs before they are authorized for sale in Canada. Includes prescription pharmaceuticals, disinfectants, and sanitizers with disinfectant claims.
The Therapeutic Products Directorate (TPD) a branch of HC is:
- Canada’s federal regulator of prescription drugs for human use.
The TPD, under the authority of the FDR:
- Reviews scientific information to assess the safety, efficacy, and quality of prescription drugs, assesses the benefits and risks, reviews clinical trial applications for studies, provides Canadians with science-based medical info they need to make informed choices.
A drug identification number (DIN) is a:
- computer-generated eight-digit number assigned by Health Canada to a drug product prior to being marketed in Canada.
- A DUN uniquely identifies the following product characteristics: manufacturer, product name, active ingredient(s), strength(s) of active ingredients, pharmaceutical form, route of administration.
Canada’s National Drug Schedules (NDS):
After Health Canada has authorized a drug for sale in Canada and determined whether it requires a prescription for sale or not, the National Association of Pharmacy Regulatory Authorities develops schedules for drugs that have been authorized for sale and classified as non-prescription by HC.
NDS Schedule 1
- Requires a prescription for sale
- Are provided to the public by the pharmacist following professional intervention of a practitioner
- Are controlled in a regulated environment as defined by provincial pharmacy legislation
NDS Schedule 2 Drugs
- Do NOT require a prescription but are only available from the pharmacist.
- Do NOT require a prescription but are only available from the pharmacist.
- Drugs are located “behind the counter” ( from an area where the public cannot access them and there is no opportunity for client self-selection)
- E.g. nitroglycerin
NDS Schedule 3 Drugs
- Do NOT require a prescription
- May pose risk for certain groups of people in self-selection.
- Available for client self-selection and should be sold where advice from the pharmacist is available when required
- E.g. fluoride used in prevention.
NDS Schedule U Drugs
- Unscheduled drugs: can be sold without professional supervision.
- Not included in Schedules I, II or III
- The labelling is considered SUFFICIENT enough to ensure that the client will make safe and effective choice and will use the drug according to its directions.
- May be sold from any retail outlet.
- E.g. acetaminophen, ibuprofen, aspirin
Narcotics and controlled substances are:
not included in the NDS, as they are scheduled according to different regulations within the Controlled Drugs and Substances Act (CDSA) and under Narcotic Control Regulations.
Controlled Drug and Substance Act of 1996
- Controlled substance = “any type of drug that the federal government has categorized as having a higher-than-average potential for abuse or addiction. Controlled substances range from illegal street drugs to prescription medications.
- Categorizes each drug into one of 9 schedules based on their potential for abuse or addiction.
Schedule I (CDSA)
- 26 types of drugs
- Highest abuse potential
- Ex: Opium and derivatives: codeine, morphine, hydromorphone, hydrocodone, oxycodone
coca, and derivatives.
Schedule II (CDSA)
- 9 groups of drugs
- Highly abused
- Until 17 Oct 2018 Cannabis was listed
Schedule III
- Moderate abuse
- Ex: LSD
Schedule IV
- Low abuse
- Ex: Barbiturates, Benzodiazpeines
Phase I of Human Drug Studies
- Small number of healthy human volunteers (~25-50)
- Small amounts of the drug is administered
- Purpose = primarily screening for SAFETY
- The biological effects and safe dose ranges in humans is determined, as well as toxic reactions.
Phase II of Human Drug Studies
- Larger group of patients WITH the target disease (~100-200) is given the drug
- Often long-term trials
- Purpose = Primarily test the EFFICACY
- Short term side effects and risks are also determined
Phase III of Human Drug Studies
- Involves large number of humans with the same condition for which the drug is indicated
- Confirmation of safety and efficacy must be demonstrated in large numbers
- Purpose = compare the safety and effectiveness against the standard treatment
- THERAPEUTIC DOSAGE is also determined during this phase.
- Can take years!
Phase IV of Human Drug Studies
- Post-marketing surveillance
- Look for toxicity of the drug after it is released
- Drugs may be removed from the market at this point if serious toxicity is shown.
