Module A - Pharmacy Basics Flashcards
5 Patients “rights”
Right Drug
Right Time
Right Route
Right Amount
Right Patient
4 General Rules for Drugs
- All drugs are poisons
- No drug is a silver bullet
- All doses are a guess
- Complacency Kills
4 main things to know for administration of drugs
Why - Reason for needing
What - Effect on the animal
How - Drug function
What - Negative or adverse effects
What is VCPR?
Vet-Client-Patient-Relationship
True or False - VCPR is not required to prescribe/sell medications
False
Two requirements to maintain VCPR
- DVM has assumed responsibility for clinical assessments and recommendations regarding the health of the animal.
- DVM has sufficient knowledge of animal to base the assessment, dx, and tx of patient
- Client has agreed to follow DVM recommendations
- DVM is available for follow up if needed
What is Pharmacology?
Study of effect of drugs on the structure and its metabolism in tissue. Both good and bad effects
What is Pharmacokinetics?
What the body does to the drug
What are the 4 movements of Pharmacokinetics?
Absorption
Distribution
Metabolism
Excretion
What is Toxicology?
Study of adverse effects of chemicals
What is a patent?
Originator given exclusive rights for set period of time (legal)
What is the withdrawal period?
Time required for drug to be eliminated from body
(Relates to food producing animals)
What is the Chemical Name for a drug?
Describes molecular structure (not what we as RVTs need to know in detail)
What is a drug?
Substance used to diagnose, treat, & prevent disease
What is the Generic Name of a drug?
Official name given to chemical name
What is the Trade Name of a drug?
Company chooses once manufacturing begins
What is another term for Trade Name?
Brand Name
How do companies consider marketing when determining Trade Name?
May have drug name in it, or created as easy to remember/sounds good
What is an Unapproved Drug (in relation to Canada)?
No DIN number
Not approved by Canadian Regulatory Body
What is a Banned Drug?
Health Canada disallows use in animals that are consumed by people
What is a compound?
When you mix ingredients. One must be a drug
Can be done in clinic or human pharmacy
What is a Nutraceutical?
“Nutrition” + “Pharmacuetical”
Often claims to provide physiological benefit or protection against chronic disease
No DIN
Not evidence based
What are the 7 sources for drugs?
- Plants
- Minerals
- Bacteria/Molds
- Animals
- Semi-Synthetic
- Synthetic
- Recombinant DNA Technology
4 groups of drugs based on physical state
Liquids
Semi-solids
Solids
Gases
True or False - Drugs are designed for convenient administration
True
True or False - Drugs are only available in one form
False (ie. Baytril = liquid, injectable, and tablets)
What are the 6 types of liquids?
Solution
Suspensions
Lotions
Liniment
Drench
Syrups
What is a solution?
Solute is completely dissolved in the solvent
Solute = dissolved substance
Solvent = dissolving substance
What type of solution uses alcohol as the solvent?
Tincture
What are the typical solvents?
Water or sterile water
Do solvents settle out?
No
What is a suspension?
Mixture where solute particles are large and suspended but not dissolved in the solvent
Do suspensions settle out?
Yes. Must be shaken well prior to use
What is a lotion?
Used for topical or mucous membrane application
(Fur must be parted or shaved for topical use)
Is a lotion soothing?
Yes
What is a liniment?
Topical application to counter irritation (superficial irritation to relieve pain deeper)
Is a liniment warm or cool?
It is either or depending on if alcohol part of the mixture (cool if added)
What is a drench?
Liquid administered orally with dropper or syringe
What is a drench typically used for?
Large animals
What is a syrup?
Contains the drug plus a flavoring liquid for oral use
What are the 5 types of semi-solids?
Ointments
Creams
Suppositories
Pastes
Gels
What is an ointment?
Usually water in oil emulsions with oil being the greater component
Is an ointment water-miscible?
No
What is an ointment usually used for?
Dry lesions
What is a cream?
Oil in water, with water being the greater component
Is a cream water-miscible?
Yes
What are creams used for?
Moist lesions
What is a suppository?
Used for insertion into the vagina, uterus, or recturm
What is a paste?
Common form of oral medication
What is a gel?
Transparent or translucent semi-solid
What are the 6 types of solids?
Tablet (tab) or caplet
Bolus
Capsule (cap)
Implants (imp)
Granules (gran)
Powder (pwr)
What is a tablet or caplet?
Firm, powder mixtures that are compressed, usually with a stabilizer, color, or lubricants
Can you break tablets/caplets apart?
Yes but only if scored and if scored, only in half
What is a bolus?
Large tablet
(In SA it is a large amount of fluid)
What is a capsule?
Powder within a gelatin case
What is an implant?
Hard pellets designed to be inserted SQ (ie. Microchip)
What is a granule?
Small ball of compressed powder
What is a powder?
The simplest form. Is usually a mixture of the drug and a diluent
What are the two main categories of administration route?
Parenteral (injections)
Non-Parenteral
What are the 4 things to consider for route to be effective?
Must be absorbed
Transported to the appropriate tissue or organ
Penetrate to the subcellular level
Elicit a response or alter an ongoing process
Route depends on what 4 things?
Chemical/physical properties of drug
Form available
Condition being treated
Characteristics of patient
What are the 2 main non-parenteral methods of administration?
Oral and Topical
What are the common routes for oral administration?
Feed, water, drench, pastes, nasogastric tubes, pills, or boluses
Are oral medications absorbed slowly or quickly?
Slowly. Absorption affected by many factors
Where are topical medications applied?
At site where it is needed (ie. on skin or other membranes)
What alternative can work for topical drug application?
Absorbed from its application site and work systemically (ie. Otic, Rectal, Vaginal, Nasal)
What is SQ/SC injection?
Subcutaneous (under the skin)
Is SQ absorption quick or slow?
Slower (~20 mins)
Can you administer irritating substances?
No
What is IM injection?
Intramuscular (into the muscle)
What is the absorption for IM Injection?
Slightly faster ~5-10 mins
Are IM injections painful?
Yes-can be
Where can you do IM injections on horses/food animals?
Cervical neck (triangle)
What are the site volume restrictions for IM injections?
Small dogs/cats = 2-3 mL per site
Large Dogs = <5mL per site
LA = 10-15 mL per site
What is IV injection?
Intravenous (into a vein)
What is absorption rate for IV Injection?
Immediate drug availability
What benefits are there to IV Injections?
Preferred for large volumes of fluid
Can be used for irritating drugs
Can you do any rate for IV Injections?
No - rate is important. Rapid rate can induce toxic/allergic reaction
What are the preferred sites for IV injections?
SA = cephalic, saphenous, jugular
Horses = Jugular
LA = Jugular, Tail
What is IA injection?
Intra-articular (into a joint)
What is important to remember for IA injection?
Absolute sterility is a must
What is IP Injection?
Intra-Peritoneal (into the abdominal cavity)
What can you use IP injection for?
Used for fluids or euthanasia solutions in pocket pets and small birds
What is IC injection?
Intracardiac (into the heart)
What are IC injections used for?
Euthanasia and perhaps for cardiac resuscitation of dying animals
What is ID injection?
Intradermal (into the skin)
What are ID injections used for?
Allergy testing
TB testing
What are subconjunctival injections used for?
To treat certain eye conditions
Where is an intra-arterial injection given?
Into an artery
When is an intra-arterial injection given?
Rarely used intentionally. Used with a tourniquet for injection of antibiotic into an artery leading to an infected bone area
What is an IO injection?
Intraosseous/Intramedullary (into the marrow cavity of bone)
When is an IO injection used?
Can be used as an emergency procedure to deliver blood and or fluids to small, severely dehydrated animals
When is an epidural used?
Injection into the epidural space between caudal vertebrae/used for anesthetic purposes
What is inhalation?
Drugs in a gaseous form delivered to the patient in inspired air
What are Pharmacodynamics?
What the drug does to the body
What are the 3 factors of pharmacodynamics?
- Involves receptor binding, post receptor effects, and chemical reactions
- Response depends on the drug binding to its target
- Concentration of the drug at the receptor site influences the drugs effect
What will pharmacokinetics knowledge aid in?
Understanding which drug is chosen
The best route is used
Side effects to watch for
What is Absorption?
Process when a drug crosses various barriers to reach the blood stream
Which route is not a factor for absorption?
IV injections
What is bioavailability?
Degree to which a drug is absorbed and becomes available by the general circulation
What are the two main methods for crossing cellular membranes
Passive process
Active Process
Is energy required for passive or active process?
Yes for active
What are the two types of passive process?
Simple diffusion
Facilitated diffusion
What is the most common method of diffusion?
Simple
What is simple diffusion?
Down a concentration gradient (higher concentration across a barrier to lower concentration site)
What is facilitated diffusion?
Water-soluble drugs cross membranes through pores or channels from high to low concentration
Lipid soluble drugs cross cell membranes by dissolving in them
What are the two types of active process?
Active transport
Pinocytosis/Phagocytosis
What is active transport?
Drugs can be transported by this method, if close in structure to endogenous substrate
What is Pinocytosis/Phagocytosis?
Less common mechanisms
Particles or droplets are engulfed
Immunoglobins are absorbed into neonate animals by this method
What 7 factors affect absorption?
Route of administration (including natural barriers within the body)
Drug Solubility (Fat vs H20)
Size of drug molecule
Ionization of the drug molecule
Formulation of the drug
Concentration of the drug
Blood supply to the absorptive area
How are oral drugs absorbed?
Absorption first occurs through GI mucosa. Occurs entire length of GI tract so large absorptive area, rich in blood supply
What can prevent or slow oral drug absorption?
Gut fill and Pyloric emptying rate = delay movement of drugs to intestines for absorption
Some may bind to gut contents
How can the GI tract affect oral drug absorption?
Low gastric pH may destroy or inactivate some drugs
Presence of GI disease is an important factor in altering the absorption of drugs
How are oral drugs absorbed in ruminants?
Large capacity of rumen dilutes drugs
pH 5.5-6.5 tends to cause ion trapping of basic drugs
Microbial activity affects the stability of many drugs
Rate of passage of feed out of the rumen depends on amount of feed taken in
How are IV and IA medications absorbed?
Eliminates need to diffuse into the circulatory system
What increases IM and SC medications absorption?
Multiple injection sites increase absorption by increasing the absorptive surface
What needs to be considered for injection medications for absorption?
Must be formulated to be:
- Pyrogen-free (not causing a fever)
- Sterile
- Adjusted to body pH
- Adjusted to body osmolality
What affects lipid soluble topical drugs absorption?
Sebaceous secretions of skin and the keratinized epithelium limit absorption
Topical medications usually formulated in fats or fat solvents
What factors increase topical drugs absorption?
When skin is broken
With increased circulation
When using a ‘vehicle’ ie. DMSO
Are inhaled drugs absorbed quickly or slowly?
Rapid absorption due to large surface area with right blood supply
Which drug solubility is faster absorbed?
Lipid-Soluble
Does size of drug matter for absorption?
Yes - the smaller the molecule, the easier it can be absorbed
What happens to large molecules during absorption?
Excluded from endothelial pores and gain access to circulation via the lymphatics instead so slowed
Does an Ion charge affect absorption?
Yes - non-ionized drugs diffuse easier
Where do basic drugs do better for absorption?
basic environment
Where do acidic drugs do better for absorption?
acidic environment
Drugs can have ___________ __________ which control the rate at which the drug is dissolved
Protective coating
True or false - many drugs are combined with carriers
True
The higher the drug concentration at a site the ____________ the absorption & why
faster - larger difference in concentration at site
The __________ the blood supply, the faster the absorption
greater
(skeletal muscle, liver, kidney)
True or False - Massage & Heat increase absorption by increasing blood flow to area
True
What is distribution?
Dispersion from site of absorption to site of action (circulatory system)
Distribution: Absorption site into __________, then into ______________ ___________ and finally into cells
Plasma, extracellular fluid (ECF)
True or False - Equilibrium between drug sites equals concentration
False
What is distribution affected by?
Concentration gradient (high -> low)
Protein Binding
Storage in various tissues
Dilution in luminal fluids
Specialized Barriers:
- Blood-brain Barrier
- Placenta
- Eye
- Joint Synovia
Disease Processes
True or False - Lower plasma proteins = more binding
False (less binding so smaller dosage required)
Where can drug go once leaves plasma compartment?
Can be stored in tissues or site of action
What tissues can drugs be stored in?
Fat, Liver, Kidney, and Bone
Drugs can enter and become trapped in _______
Luminal fluids (dilution)
What is blood-brain barrier?
Barrier between plasma & ECF of brain
_____________ cells of capillaries have _______ junctions instead of pores
Endothelial, tight
How to nutrients enter to BBB?
active transport (carrier mediated systems)
True or False - Neonates have less efficient BBB
True
True or False - Placenta is as effective as BBB to many drugs
False
_________-Soluble drugs diffuse across placenta barrier easily
Lipid
Where do tight capillary endothelium junctions limit absorption and distribution exist?
The eye, joint synovia, BBB
True or False - Purulent & Necrotic debris may bind and inactivate some antibiotics
True
True or False - Renal & Hepatic diseases can affect protein binding
True
What is biotransformation also known as?
Metabolism
What is metabolism/biotransformation?
Body’s ability to change a drug’s chemical form from when it was administered to a form that can be eliminated by the body
A drug that has undergone a chemical change is said to be _______________
Metabolized
A drug that is altered is called a ___________
Metabolite
True or False - All drugs can be metabolized
False - Some circulate and are excreted in an unchanged form from that which they were administered
What 3 things can drug metabolism use?
- Reduce activity/toxicity (most common)
- Increase activity/toxicity (not common)
- Change it to a form that is readily excreted
True or False - Some drugs require metabolism to be active
True
Where does metabolism mainly occur?
Liver
Amount of enzymes available for metabolism depends on?
Species (cats have limited ability for select drugs)
Age (young have underdeveloped systems)
Sex (male anabolic steroids increase production) Stress (decreased in increased stressed)
Nutritional status (malnourished VV production)
Disease (especially liver disease)
Enzyme Induction (from repeated use)
What is first pass effect?
Absorbed from gut, enter hepatic portal circulation, filtered by liver, enter systemic circulation
Some of drug may be metabolized before it reaches systemic circulation and target site
Does first pass effect increase or decrease bioavailabilty?
Decrease (to point ineffective)
True or False - First Pass Effect is used on IV and Oral drugs
False - Oral drugs only
What is the major route for drug excretion?
Kidney (renal)
Renal excretion requires drug to be _________ soluble
Water
What other system needs to be functioning normally for renal excretion?
Lower Urinary Tract
Where does biliary excretion occur?
Liver - through bile into GIT, excreted through feces
What is Intestinal Excretion?
Secreted across GIT mucosa by active transport, eliminated through feces
True or False - Some drugs can be secreted unchanged, especially basic, fat-soluble drugs
True
Quantities of drug found in milk or meat are called what?
Residues
Gas anesthetics eliminated through?
Expired air/Exhalation
What is half life?
Estimation of rate of drug loss from the body / Time required for blood concentration of a drug to decrease/eliminated by 50%
