Lec4 Flashcards
Therapeutic Range
drug concentration in the body that produces the desired effect with minimal or no signs of toxicity; Detrimental effects are minimal and benefits are maximal
Solutions
clear liquid preparations that contain 1 or more solvents and one or more solutes
Solvents
usually sterile water added to a dry powder medication creating a solution for IV injection
Suspensions
liquid preparations that contain solid drug particles suspended in a suitable medium
are “suspended” but not dissolved
drug particles settle out on standing
must always shake before using
What is the major rule regarding Solvents?
almost all products that are suspensions are NOT administered by an IV route
exception to this rule is Propofol®
Powders and Granules
May be added to the food
May absorb (cornstarch)
May lubricate (talcum powder)
Tablets
medicines mixed with an inert binder and molded or compressed into a hard mass; disintegrates in the stomach liquid, releasing the drug for absorption into the bloodstream
What are some different sizes of tablets
Pellets, Boluses, Bollettes and Bolloids
Enteric Coated
covered with a special coating that prevents the drug from dissolving in the stomach; Resists breakdown in stomach acid
Useful for medications that may be harmful to the stomach
Time Released
variable rate of breakdown of coating allows for delayed release leading to more consistent blood levels
Capsules
gelatin shells holding a powdered or liquid form of the drug
Most are colored and may bear identifying product markings
Time Released encapsulated
with variable rate breakdown of coating allowing for delayed release (leads to steadier blood levels)
Microencapsulated
newer drug form that stabilizes substances that need protection
Masks the smell and taste of the drug
Liniment
a drug(s) suspended in oily, soapy or alcoholbased substance
Applied topically (sometimes with friction) to relieve pain/counterirritant
May produce heat
Lotion
a drug(s) suspended in a liquid
Applied gently by dabbing, brushing or dripping on skin without friction
Soothing effect
Cream
a drug(s) suspended in wateroil emulsion
Gel
a drug(s) suspended in semisolid or jellylike substance
Ointment
a drug(s) suspended in a semisolid, greasy preparation that melts at body temperature
Paste
a drug(s) suspended in a semisolid preparation that retains its state at body temperature
Applied to skin, eyes, ears, etc.
Many pastes are given orally
“repository” or “depot”
Placing an injectable drug(s) in a substance that delays absorption
Suppositories
Conical/ Ovoid Solid or Semisolid Material Inserted into Body Orifices
Melt at body temperatures
Frequently used in humans
Diazepam persistent seizures
Narcotics pain control
Liquid medications such as narcotics administered into the rectum are considered suppositories
Inhalations
Liquid that may be converted into an aerosol or mist to be used in a vaporizer or nebulizer and inhaled; Drugs that are inhaled are rapidly absorbed into the blood stream
Inhalation administration introduces the drug to the animal by having it breathe the drug into it’s lungs
The gas particles enter the alveoli of the lung where they diffuse (move from higher to lower concentration) across the alveolar membrane into the surrounding capillaries
Often used for emergency procedures
Volatilized
Turned into Gases
Nebulized
Turned into a Fine Mist
Inhalers
Bronchodilators open the airway for better breathing
Steroids used to treat inflammatory lung conditions
Preservatives
Antimicrobial agents that increase the shelf life of a product by decreasing the likelihood of microbial growth
Factors to consider when determining Routes of Administration
Speed or Rapidity of Onset slower effect seen with oral administration vs. IV
IV has the most rapid onset of action
Site of Action in Patient’s Body some sites difficult to reach by conventional means
Some drugs must be specifically formulated to penetrate certain areas such as the prostate, brain, and joint space
Physical and Chemical Properties of the Drug Acid / Base Status
pH of injectable barbiturates (thiopental) cause tissue necrosis if given perivascularly
Potential Adverse Effects / Reactions
Dosage Form of the Drug Available
Some Drugs are Only Available in Certain Forms
Temperament of the Patient Being Treated
Some patients are Fear Biters or Aggressive.
Are Not the Best Candidates for Oral Meds
Abilities of the Client
Drops vs. Pills
Enteral / Nonparentaral
Delivers the medicine directly to the animal’s GI tract
Refers to an oral route of administration
Specifically the small intestine
Most convenient to give
Slower onset of action/longer duration of action
Less likely to cause adverse reactions
Don’t need to be sterile
Absorption may be erratic /incomplete due to effect of gastric fluids
May be affected by GI disease
Parenteral
delivers the drug by a route other than the GI tract (means “excludes the intestine”)
IV, ID, IM, IC, SQ , Epidural/Subdural/Intrathecal, IP, Intraarticular, IA, Topical, Inhalation, Intramedullar/Intraosseous
Intravenous (IV)
within the vein
Rapid onset of action/high initial blood levels
Short duration of action/frequent dosing
Smaller doses can be administered
Increased risk of adverse effects
Drugs must be pure, sterile and free of particles
Drug must be water soluble
Irritating/caustic drugs given by the IV route
Intramuscular (IM)
within the muscle
Relatively rapid onset (usually about 30 minutes)
Absorption depends on drug formulation
Gives reliable blood levels
Longer duration of action than IV, but shorter than SQ or PO
Cannot use for irritating drugs
Convenient route in fractious animals
Subcutaneous (SQ, subQ, SC)
beneath the skin into the subdermis
Slower onset of action/longer duration of action than IM or IV
Less reliable blood levels
Cannot use for irritating drugs
Absorption depends on drug formulation
Can be used for administering
large volumes of solution
(fluid administration)
Intraperitoneal (IP)
within the abdominal body cavity
Onset of action/blood levels variable
Provides large surface area for absorption
Irritating solutions may lead to peritonitis
Must be careful not to penetrate vital abdominal organs
Drug may be inactivated or enhanced through first pass effect (via hepatic portal system)
Epidural/Subdural/Intrathecal
above or under the dura mater of the meninges, or into the subarachnoid space of the meninges
Rapid onset of action localized to the CNS
Used for anesthesia and diagnostically with contrast media (e.g. myelogram) or to obtain spinal fluid
Potential for accidental spinal cord injection and/or other CNS damage
Intradermal (ID)
within the skin
Injection between the dermis and epidermis
Absorption very slow/blood levels low
Mainly used for T.B. and allergy testing
Intraarterial (IA)
within the artery
Used mainly for treating a specific organ due to extremely high blood levels delivered to the site
Often accidental (attempting to administer drug into the jugular vein)
Intracardiac (IC)
within the heart
Very rapid blood levels
Mainly used for emergency drug administration and euthanasia
Intraarticular
within the joint
Injection into the synovial space of joints
Aseptic technique is critical
Drug may be absorbed systemically
Intramedullay or Intraosseous
within the medullary cavity of bone
Provides rapid blood levels
Often used for rapid fluid administration in smaller animals and birds
Usually administered in the femur or humerus
Not commonly used and may be painful
Topical applied on top of a surface
Used mainly in dermatology and ophthamology
Good local effect/systemic absorption variable
Drug must first dissolve and penetrate the skin by diffusion
Easy to administer
Animals may chew/lick or rub drug off
May be irritating
Includes nasal, conjunctival, intramammary, transdermal, rectal, and vaginal routes
Dose
the amount of drug administered at to a patient at one time to achieve the desired effect
Dosage
the amount of drug per body weight of the animal (or other measure such as surface area)
Dosage Interval
how frequently the dosage is given
Dosage Regimen
the dosage interval and dosage together
Loading Dose
the initial dose of drug given to achieve drug concentration in the therapeutic range quickly
Maintenance dose
the dose of drug that keeps drug concentration in the therapeutic range
Total Daily Dose (tdd)
the total amount of drug delivered to the patient in 24 hours
Ways to maintain drug levels in the therapeutic range and benefit the animal include:
Use proper dosage, frequency and duration of treatment
Avoid combination drug therapy if possible
Use the least toxic drugs available
Be familiar with potential hazards and precautions
Use high quality drugs, check expiration dates, know handling requirements
Understand contamination possibilities and make sure suspensions are mixed and solutions are not precipitated
Follow label directions carefully
Know the patients history and maintain communication with the client
If drug toxicity develops:
Stop or remove the offending drug
Enhance drug removal by the animal (induce vomiting if appropriate, administer fluids)
Counteract or reverse with an antidote if available
Provide supportive nursing care until signs of toxicity are gone
Most common causes of drug toxicity include:
Outright overdose
Relative overdose
Side effects
Accidental exposure
Drug interactions
Incorrect treatment/misdiagnosis
The “Rights of Drug Administration”
Right Drug
Right Dose
Right Route
Right Time
Right Patient
Right Documentation
