RCP PHARM midterm Flashcards
Pharmacology
study of drugs, including the origins, properties, and interactions with living organisms
Pharmacogenetics
the study of interrelationship of genetic differences and drug effects
Pharmacognosy
the identification of sources of drugs, from plants and animals
Toxicology
the study of toxic substances and their pharmacologic actions, including antidotes and poison control
Therapeutics
the art of treating diseases with drugs
Generic drug name
name assigned (by US adopted name council) when the chemical appears to have therapeutic use and the manufacturer wishes to market the drug (nonproprietary name)
Chemical name
name indicating the drug’s chemical structure
Official name
in the event that an experimental drug becomes fully approved for general use and is admitted to US Pharmacopeia-National Formulary, the generic name becomes the official name
Trade name
brand name of proprietary name, given by particular manufacturer
Thyroid hormone, insulin, pancreatic dornase drug source
Animal
Khellin (Ammi visnaga), Atropine (belladonna alkaloid), Digitalis (foxglove), Reserpine, Volatile oils of eucalyptus, pine, anise drug source
Plant
Copper sulfate, Magnesium sulfate (Epsom salts), Mineral oil (liquid hydrocarbons) drug source
Mineral
Generic drug difference
any manufacturer’s version of the prescribed drug and not a specific brand (cheaper)
Illegal drugs difference
controlled substances not prescribed by pharmacist nor bought at drug store
Over the counter (OTC) drugs difference
does not require a prescription for purchase, strength and amount per dose is less and may encourage “self-treatment” that could mask or complicated a serious medical condition
What drugs can be aerosolized?
- adrenergic
- anticholinergic
- mucoactive
- corticosteroid
- antiasthmatic
- antiinfective
- surfactants
Enternal route of adminstration
=refers to small intestine, intended for absorption anywhere along the GI tract (most common by mouth)
- Tablet, capsule, suppository, elixir, suspension
Parental route of administration
=injectable
- IV (Intravenous [IV]) → directly into vein
- IM (Intramuscular [IM]) → deep into skeletal muscle
- SC (Subcutaneous [Subcu, SubQ]) → subcutaneous tissue beneath epidermis and dermis
- IT (Intrathecal) [arachnoid membrane of the spinal cord] → diffuses in spinal fluid
- IO (Intraosseous [IO]) → marrow of bones
Transdermal route of administration
= application to skin
- Patch, paste
Inhalation route of administraton
= local (respiratory tract) or systemic effect
- Gas, aerosol
Topical route of administration
= applied directly to skin or mucous membranes to produce local effect
- Powder, lotion, ointment
Factors affecting drug absorption
Barriers can affect the drug’s time to onset and time to peak effect:
-bioavailability is influenced by absorption and by inactivation caused by stomach acids and by metabolic degradation (can occur before drug reaches main systemic compartment)
-blood flow to site absorption
Drug metabolism
=drug molecules are metabolized or bio-transformed, constitute a complex area of biochemistry
- liver
Biotransformation
= refers to the process by which lipophilic (fat-soluble), xenobiotic (foreign), or endobiotic (endogenous) chemicals are converted in the body by enzymatic reactions to products that are more hydrophilic (water-soluble)
First-Pass effect
= If a drug is highly metabolized by the liver enzymes and is administered orally, most of the drug’s activity is terminated in its passage through the liver before it ever reaches the general circulation and the rest of the body (…the concentration of a drug is greatly reduced before it reaches the systemic circulation)
Drug excretion (elimination)
=measure of the ability of the body to rid itself of the drug
- kidneys
Maintenace dose
= To achieve a steady level of drug in the body, dosing must equal the rate of administration.
Plasma Half-Life (T ½)
= The time required for the plasma concentration of a drug to decrease by one-half; a measure of how quickly a drug is eliminated from the body
Local drug effects
=topical deposited agent, inhaled aerosol strictly affects the upper or lower airways
- exemplified by a nasally inhaled vasoconstricting agent (decongestant) or by an inhaled bronchodilator aerosol
Systemic drug effects
= inhaled aerosol for the drug to be absorbed and distributed in the blood
- exemplified by the administration of inhaled zanamivir (Relenza) to treat influenza, inhaled morphine for pain control, or inhaled insulin aerosol for systemic control of diabetes
Penetration of drugs reaching respiratory tract
= Referring to the depth within the lung reached by particles
- 50%-60% of the drugs impacts the mouth or oropharynx
- 90% reaching the stomach
- 10%-30% being delivered to lower respiratory tract (depending on delivery device)
- Newer aerosol-generating devices are proving efficiency of 30% to 50% (more of the dose)
Efficiency of drugs reaching respiratory tract
= perfectly efficient inhalation device would deliver all the drugs to the luing and none to the oropharynx or GI tract
L/T ratio
= Proportion of drug available from the lung, out of the total systemically available drug
L/T ratio formula
(Lung dose) / (lung dose + GI dose)
- higher the ratio, the more efficient the aerosol drug delivery to the respiratory tract
Deposition of drugs reaching respiratory tract
= Describing the process by which particles deposit out of suspension to remain in the lung
- An increase in mean residence time or tidal volume enhances drug deposition in lungs, while an increase in air flow decreases the mean residence time, resulting in the decrease of total deposition of drug particles
Gravitational settling of drugs reaching respiratory tract
= Functional size and time of particle in the last five to six generations of airways (smaller bronchi and bronchioles), where air velocity is low
- use of a “breath hold” can increase settling of particles
Tolerance
= decreasing intensity of response to drug over time
Hypersensitivity
= allergy or immune-mediated reaction to a drug, which can be serious, requiring airway maintenance or ventilatory assistance
Tachyphylaxis
= rapid decrease in responsiveness to a drug
Agonist
= a drug or chemical that binds to a corresponding receptor (has affinity) and “initiates” a cellular effect or response (has efficacy)
Antagonist
= a drug or chemical that is able to bind to a receptor (has affinity) but causes no response (zero efficacy) –> Inhibits or Blocks
Synergism
= occurs when 2 drugs act on a target organ by different mechanism of action, and the effect of the drug pair is greater than the sum of the separate effects on the drugs
Bioavailability
= proportion of a drug that reaches the systemic circulation
Aersol
= Suspension of liquid or solid particles between 0.001 and 100 µm (micrometers; aka: Microns) in diameter in a carrier gas.
Three main uses:
- Humidification using bland aerosols
- Improved mobilization and clearance of secretions
- Delivery of aerosolized drugs to respiratory tract
Particle size (MMAD) (µm) for Diagnostic and Therapeutic applications
MMAD= Mass median aerodynamic diameter
- size of interest for pulmonary applications is in the range of 1 to 10 µm (micrometers; aka: Microns)
Particles greater than 10um= useful to treat the nasopharyngeal and oropharyngeal regions
Particles 5-10um= shift deposition in central airways or oropharyngeal
- early airway generations (first six generations)
Particles 2-5um= overall lower respiratory tract (larger airways to peripheral)
- considered useful for the bronchoactive aerosols currently in use
Particles 0.8-3um= Increased delivery to the lung parenchyma, including the terminal airways and alveolar region
Breath-actuated jet nebulizer
= release aerosol only during inspiration because they are designed to increase aerosol drug delivery to patients by reducing loss of medication during expiration
Jet nebulizer
= Small-reservoir, gas-powered (pneumatic) aerosol generators
- Commonly used and exhibits a large amount of drug wastage
- Pt compliance is directly proportional to convenience!
- Use a jet-shearing principle for creation of an aerosol from the drug solution
Jet nebulizer 4 categories
- Jet nebulizer with reservoir tube (only 10% to 20% of emitted dose is inhaled)
- Jet nebulizer with collection bag/elastomeric ball
- Breath-enhanced jet nebulizer
- Breath-actuated jet nebulizer (aka: AeroEclipse)
Small volume nebulizer (SVN)
= type of aerosol generator that converts liquid drug solutions or suspensions into aerosol
Ultrasonic nebulizer (USN)
= Electrically powered devices
- Operate on the piezoelectric principle
- Capable of high output
- Small, portable units that can operate on direct current (DC) voltage
Metered dose inhalers (MDIs)
= Excellent choice for drug delivery
- Should be paired with right patient (pt)
- Used spacer or valved-holding chamber to help overcome any limitations
DPI
= Main advantage is that the DPI is breath-actuated
Flow meter flow (LPM) devices
SVN= Operate at 6-8 Lpm
Breath-actuated nebulizer= inhalation flow rate close to 25 L/min
USN= Rate of flow: 0-2 mL per min, or 0-120 mL per hour.
MDI= Flow rates: between 30 and < 60 L/min ( flow rate of 60 L/min allows for optimum inhalation)
DPI= Inspiratory flow rate between 30 and 90 L/min is needed!!
Chlorofluorocarbon (CFC)
= one CFC molecule can destroy 100,000 molecules of statospheric ozone
- removed from market/FDA banned them
Hydrofluoroalkane (HFA)
= propellants that were nontoxic to the atmosphere and to the patient and that also had properties suitable for MDI aerosol generation
53%
SVN advantages/disadvantages
SVNs advantages:
- ability to aerosolized many drug solutions
- ability to aerosolized drug mixtures
- minimal cooperation or coordination required for inhalation
- useful in very young or very old, debilitated patients, and patients in acute distress
- effective with low inspiratory flows or volumes
- normal breathing pattern can be used, and inspiratory pause
- drug concentrations and dose can be modified
SVNs disadvantages:
- equipment required for use is expensive and cumbersome
- treatment time lengthy
- variability in performance
- contamination possible
- assembly and cleaning required
- wet, cold spray
- may deposit in eyes
- power source needed
Ultrasonic nebulizer advantages/disadvantages
Ultrasonic nebulizer advantage:
- small size
- rapid nebulizer with short treatment time
- smaller drug amounts with no diluent for filling volume
- can be used during car travel or camping
Ultrasonic nebulizer disadvantage:
- high expense
- fragility, lack of durability
- requires electrical sours (either AC or DC)
- possible degrading effect on drug must be determined
DPI advantages/disadvantages
DPI advantages:
- Small and portable
- Short preparation and administration times
- Breath actuation; no need for hand-breathing coordination
- No inspiratory hold or head tilt needed
- No CFC propellants (environmentally friendly)
- No cold Freon effect to cause bronchoconstriction or inhibit full inspiration
- Simple determination of remaining drug doses
- Built-in dose counter
DPI disadvantages:
- Only a limited range of drugs is available to date
- Patients (pts) are not as aware of the dose inhaled as with an MDI and may distrust delivery
- Moderate to high inspiratory flow rates are needed for powder dispersion
- Relatively high oropharyngeal impaction and deposition can occur
- A device such as the Aerolizer is a single-dose device and must be loaded before each use
- Vulnerable to ambient humidity or exhaled humidity into mouthpiece
- Different DPI needed with different drugs
- Easy for patient (pt) to confuse directions for use with other devices
MDI advantages/disadvantages
MDI advantages:
- pMDIs are portable, light, and compact
- Drug delivery is efficient
- Treatment time is short
- They are easy to use
- More than 100 doses are available
- Fine particle sizes are available in hydrofluoroalkane (HFA) formulations
- They are difficult to contaminate
- No drug preparation is needed
- It is possible to reproduce emitted doses
MDI disadvantages:
- Complex hand-breathing coordination, proper inhalation pattern, and breath hold are required
- Drug concentrations and doses are fixed
- Canister depletion is difficult to determine accurately
- Reactions to the propellants may occur in small percentage of patients
- High oropharyngeal impaction and loss occur if an extension device is not used
- Foreign body aspiration of coins and debris from mouthpiece can occur
SVN dose of albuterol
0.5 cc or 2.5mg (2500mg)
MDI dose of albuterol
2 puffs or 0.2mg (200mg)
Gram measurement
1 Kilogram (kg) → 10^3 → 1000 grams
1 Gram (g) → base unit → 1 gram
1 Milligram (mg) → 10^-3 → 0.001 gram
1 Microgram (mcg or ug) → 10^-6 → 0.000001 gram
Liter measurment
1 Liter (L) → Base unit → 1 Liter
1 Centiliter (cL) → 10^-2 → 0.01L
1 Milliliter (mL) → 10^-3 → 0.001L
Meter measurements
1 Meter (m) → Base unit → 1 meter
1 Centimeter (cm) →10^-2 → 0.01M
1 Millimeter (mm) → 10^-3 → 0.001M
1 Micrometer (um) → 10^-6 → 0.00001M
Central nervous system (CNS)
= system that includes the brain and spinal cord/controls voluntary and involuntary acts
Peripheral nervous system
= portion of the nervous system that includes sensory, sympathetic, and parasympathetic systems
Sensory
= afferent neurons from heart, light, pressure, and pain receptors sending information from the peripheral to CNS
Somatic
= under voluntary, conscious control and innervates skeletal muscles for motor actions
Autonomic nervous system
= involuntary/unconscious control mechanism of the body, sometimes said to control vegetative or visceral functions (sympathetic/parasympathetic)
Anticholinergics
= “Block” acetylcholine receptors
- Atropine as a prototype parasympatholytic agent → blocks salivary secretion and causes dry mouth
- Competitive antagonist
- Bronchodilation
- Preoperative drying of secretions
- Antidiarrheal agent
- Prevention of bed-wetting in children
- Treatment (tx) of peptic ulcers, organophosphate poisoning, mushroom ingestion, bradycardia
Sympathomimetics
= agent causing stimulation of the sympathetic nervous system
Sympatholytic
= agent blocking or inhibiting the effect of the sympathetic nervous system
Parasympathomimetic
= agent causing stimulation of the parasympathetic system
Parasympatholytic
= agent blocking or inhibiting of the parasympathetic system
Short-acting B agonist (SABA)
= (albuterol/levalbuterol) are indicated for relief of acute reversible airflow obstruction in asthma or other obstructive airway diseases (COPD)
Long acting agents (LABA)
= “controller”/indicated for maintenance of bronchodilation and control of bronchospasm and nocturnal symptoms in asthma or other obstructive diseases (COPD)
Theophylline (Tea leaves)
= generally classified as a bronchodilator with relatively weak bronchodilating effect
- Methyl attachments at N-1 (nitrogen-1) and N-3 (nitrogen-3) enhances bronchodilation/increase side effects
Effects associated with a range:
- < 5(less than) μg/mL: No effects seen
- 10 to 20 μg/mL: Therapeutic range
- > 20 μg/mL: Nausea
- > 30(greater than)ug/mL: Cardiac arrhythmias
- 40 to 45 μg/mL: Seizures
- Asthma management= 5 to 15 μg/mL
- COPD management= 5 to 10 μg/mL
Common side effects:
- Gastric upset
- Not recommended in pts with peptic ulcer or acute gastritis
- Headache
- Anxiety and nervousness
- Diuresis
Conditions that Increase theophylline serum levels, because of decreased liver metabolism of the drug
- Viral hepatitis
- Left ventricular failure
Condition that Decreases theophylline serum levels (Opposite effect), because of increased liver enzymes that inactivate
- Smoking
Caffine
= Additional methyl group at N-7 (nitrogen-7) decreases bronchodilation; causes CNS stimulation to breathe
Side effects:
- tachycardia
- skeletal muscle stimulation
Mucus
= secretion from surface goblet cells and submucosal glands composed of water, proteins, and glycosylated mucins (the secretion)
Phlegm
= purulent material in the airways
Sputum
= expectorated phlegm that contains respiratory tract, oropharyngeal, nasopharyngeal secretions, bacteria, and products of inflammation (polymeric DNA/actin)
Mucus color
- Yellow mucus= infection
- Green mucus= serious infection
- White= irritation/allergy
- Brown= blood in nose/inhalation of dust or particles (common in smokers)
Mucolytics
= medications that degrade polymers in secretions
Expectorants
= medications meant to increase the volume or hydration of airway secretions
Mucoactive agents
= any medication or drugs that have an effect on mucus secretions (mucolytic, expectorant, mucospissic, mucoregulatory, mucokinetic)
Hyperosmolar (Hypertonic) saline (7%)
= airway clearance for theory of CP
- Irritant to induce cough
- Can improve mucociliary transport and lung function
- May increase FEV1 in patients
- Alternate effect is an acute decrease in FEV1
- Unpleasant taste; coughing may make it unsuitable for long-term use
Acetylcysteine
= used to prevent Liver damage from acetaminophen overdose and the contrast used in CT Scans
- Treatment of conditions associated with secretions of viscous mucus
- As an antidote for Acetaminophen (Tylenol) overdose to reduce Hepatic (Liver) injury as well as contrast used in CT scans.
- NAC disrupts the structure of the mucus polymer by substituting free thiol (sulfhydryl) groups for disulfide bonds connecting mucin proteins
Hazards:
- Bronchospasm (especially in Asthmatic pts)= Less common with 10% solution!
- May cause nausea or vomiting= Smell - hydrogen sulfide
- Mechanical obstruction of airway
Dornase alfa
= To preserve or improve lung function in CF while reducing the frequency and severity of respiratory infections by improving secretion clearance
- First approved mucoactive agent for the tx of CF
- For clearance of purulent secretions
- To reduce frequency of respiratory infections requiring parenteral Antibiotics (Abx)
- To improve or preserve pulmonary function
Mode of action (when given by aerosol):
- Reduces viscosity and adhesivity by breaking down DNA
Dose and administration:
- Available as single-use ampule
- 2.5 mg of drug in 2.5 mL of clear, colorless solution
- Should be refrigerated and protected from light
Common side effects:
- Voice alteration
- Pharyngitis
- Laryngitis
- Rash
- Chest pain (CP)
- Conjunctivitis
LaPlace’s law
= physical principle describing and quantifying the relationship between the internal pressure of a drop or bubble, the amount of surface tension, and the radius of the drop or bubble
LaPlace’s law bubble calculation
Pressure= (4 x surface tension)/ radius
LaPlace’s law alveoli calculation
Pressure= (2 x surface tension)/ radius
Surfactant
= a surface active agent that reduces surface tension (alveoli) (also called detergents)
Exogenous
= surfactant preparations from “outside” the patient’s own body; can be obtained from other humans, from animals, or by laboratory synthesis.
- replace missing pulmonary surfactant in respiratory distress syndrome (RDS) of newborns
Endogenous
= kind of surfactant occurs naturally in the body and is produced by alveolar type II cells
Apnea of prematurity- AOP
= Premature babies often suffer AOP as a physiological consequence of an immature respiratory system.
- pauses breathing for more than 15 to 20 seconds. or. pauses breathing for less than 15 seconds, but has a slow heart rate or low oxygen level\
- Caffeine citrate penetrates cerebrospinal fluid (CSF) better and has a higher therapeutic index with fewer side effects compared with theophylline
- It appears to be more common during sleep, especially during active sleep — a period when your baby has rapid eye movement (REM) while sleeping
- Apnea may be followed by bradycardia (decreased heart rate)
- With bradycardia, when your baby’s breathing slows, the heart rate also slows
- A common term for apnea with bradycardia is “As and Bs.“
Respiratory distress syndrome (RDS)
= Clinically indicated for tx or prevention of RDS in newborns
- Prophylactic treatment
- Beractant (survanta)/Calfactant (Infasurf) → Modified natural surfactant from calf lung (bovine)
- Prevention of RDS in very-low-birth-weight infants
- Infants with higher birth weights, but with evidence of immature lungs
- Infants who are at risk for developing RDS
- Rescue treatment
- Retroactive or “rescue” treatment of infants who have developed RDS
- Basic problem in RDS is lack of pulmonary surfactant as a result of lung immaturity resulting in high surface tension in the liquid-lined, gas-filled alveoli (Without Exogenous Surfactant, increased ventilating pressure is required to expand the alveoli during inspiration)
Pharmacokinetics
Time course and disposition of a drug in the body based on its absorption
Pharmacodynamics
Mechanisms of drug action by which a drug molecule causes its effect in the body
Open-ended questions
= asks the patient to provide narrative information
THOUGHT PROVOKING
Begin the interview, introduce new questions, and gather further information whenever the patient introduces a new topic
Unbiased
Examiner stops and listens to patients concerns (long answers)
“Tell me about it” “Anything else?” type of questions examiners ask (build and enhance rapport)
