Pharm Quiz 1 Flashcards
What is a threshold dose?
When the response starts to show
What is the ceiling effect?
See no more effect from the dose
What is therapeutic range?
When there is an increased response from the dose
Dose- response curve refers to response in?
A single patient
What does Quantal D-R curve determine?
Dose that causes specific response in a group
Higher Ti indicated a safer or more harmful drug?
Safer
What are the key issues of pharmacokinetics?
Absorption
Distribution
Metabolism
Excretion
What is absorption?
how the drug moves from tissue to bloodstream
What are some examples of enteral route of admission?
Oral
Lingual
Buccal
Rectal
What are some examples of parenteral route of admission?
Injection
Inhalation
Topical
Transdermal
Other
What is the trade off of enteral routes?
Fairly simple but less predicable absorprtion
What is the trade off of parenteral routes?
More difficult but more predictable absorption
What is bioavailability?
Percent administered dose that appears in bloodstream
What is the first pass effect?
Some of the drug is destroyed in first pass of liver
What are some factors that affect distribution?
- Admin routes
- Properties of drug
- Binding to plasma proteins
- Barriers and carriers
What are some primary storage sites for drugs?
Fat
Muscles
Bone
Liver
Kidneys
Organs/tissue
What are primary problems of storage?
Local tissue damage
Redistribution
What does metabolism (biotransformation) do?
Active form of drug is changed chemical to an inactive or less active by product or metabolite
(often creates more polar, water soluble metabolite that can be excreted by kidneys)
Where is the primary site of biotransformation?
liver
What are other sites of biotransformation?
Lungs
Kidneys
GI tract
Skin
What is an active metabolites?
Some can continue to exert effects for a while
Where is the primary site of excretion?
Kidneys
What are some other significant site of excretion?
Lungs
Gi tract
What are some minor sites of excretions?
Sweat
Saliva
Breast milk
What is clearance?
Rate that drug can be removed completely from body
What causes a drug to be cleared best?
If organ has high blood flow and good extraction ratio
What can impair an organs ability to clear drugs?
Any disease or illness that affects blood flow or extraction ratio
What is the problem with decreased clearance time>?
Prolonged medication effects and side effects
What is a half life?
amt of time required for 50% of active form of drug to be eliminated
What happens if drugs are given continuously?
Maintain fairly stable level of drug in blood stream
What happens if drugs are given intermittently?
Cause peaks and troughs in plasma level
What are some factors that affect normal pharmacokinetics?
Disease
Age
Genetics
Gender
Body compositions
Diet
Other chemical
Physical factors
What implication does pharmacokinetics have on implication for rehab?
Timing of session with drugs peak and troughd
What is the implication of pharmacokinetics on absorption/ distribution?
Increased by heat, exercise, massage
Decreased by cole
What are analgesics meds?
Opioids
Nonopiods
What are some anti-inflammatory agents?
NSAIDs
Glucocorticords
What does opioids do to pain?
Alter perception
When are opioids indicated?
Acute pain
Chronic pain
What do strong agonist opioids do?
Really good at binding to receptor on tissue to stimulate
What do moderate opioids do?
Kinda good at binding to receptor on tissue to stimulate
What do antagonist opioids do?
Block receptor
What do mixed agonist/antagonist opioids do?
Stimulate certain receptors and block others
What is the primary mechanism of action for opioids?
Act primarily on spinal cord and brain and bind to specific receptors located on presynaptic nerve terminal and postsynaptic neurons
What effect can opioids have on peripheral (sensory) neurons?
Decrease sensitivity of neuron that initiates painful impulse
what effect can opioids have on descending (efferent) pain pathways?
Remove inhibition of central anti-pain circuits
Why do we have receipts in our body for drugs like morphine?
Certain situation body produces endogenous opioids
Are receptors located only in brain and spinal cord?
No, found other place which mean they can affect many tissues/organs outside CNS
In general what are the 3 ways opioids can control pain?
- Decrease synaptic activity in ascending pain pathways
- Decrease sensitivity of sensory neurons that send painful impulse to cord
- Activate descending anti-pain pathways
What are relatively minor opioids adverse reactions?
Sedation
Mood changes
Confusion
Nausea/Vomiting
Constipation
What are some more serious opioids adverse effects?
Orthostatic hypotension
Respiratory depression
Potential for tolerance, dependence and addiction
What is opioid tolerance?
Need more drug to achieve same effect
What is physical dependence?
Onset of withdrawal if drug suddenly stopped
What is the time course of opioid tolerance?
Begin: after 1st dose
Obvious: 2 to 3 wks
Lasts: 1 to 2 wks after opiod stopped
When can withdrawal begin, peak and last?
Begin: 6-10 hours after last dose
Peak: 2-3 days
Last: 5 days
When is the risk for addiction low with short term opioids use>
- Used limited (3-7 days)
- Dosage matches pt pain levels
- Pt does not have history of substance abuse
- Pt doesn’t misuse drug
What is chronic opioids analgesic therapy defined as?
> 90 days of continuous use
What is PCA?
Patients controlled analgesic
PCA benefit?
Better pain control
Increase pt satification
Require pt awareness
What is opioid induced hyperalgesia?
Opioids may be ineffective or increase pain
What are the primary effects of NSAIDs?
Analgesic
Anti-inflammatory
Antipyretic
Anticoagulant
What is NSAIDs mechanism of action?
inhibit synthesis of prostaglands
What are some adverse effects of NSAID?
Stomach irritation
Hepatic, renal toxicity
CV problems
Impaired bone healing
Overdose
What is COX-1?
Synthesize PG to protect and maintain function
What is COX-2?
Synthesize PGs that mediate pain, inflammation
What do COX-2 selective drugs do?
Inhibit synthesis of PGs in pain, inflammation
- Spare production of beneficial PGs in stomach, kidney and lately
Why may COX-2 inhibition promote infarction?
PG’s that cause vasodilation and contraction are in balance. COX-2 selective drugs inhibit vasodilaitng PG causing constriction
Acetaminophen overview?
Analgesic & antipyretic effects
- No gastric irritation
- No anti inflame or anticoagulant effect
- High dose= liver toxicity
What are the adverse effects of anti-inflammatory steroids?
Catabolic effect on bone, muscle, ligament, tendon, skin
Could cause adrenal suppression
When can adrenocortical shock occur?
When glutocorticosteriods are stopped suddenly
