Intro + Pain Control Flashcards
PK/PD, Opioids, NSAIDs, Neuropathic pain, RA, SLE, and OA
Pharmacokinetics definition
what the body does to a drug involves ADME
Pharmacodynamics definition
how a drug affects a body
what does ADME stand for?
absorption distribution metabolism excretion
what are the 3 steps in the FDA drug approval process?
identify new drug need FDA IND Clinical trials
what are the 4 phases of clinical trials?
- safety 2. efficacy 3. larger and longer RCT 4. post marketing surveillance
how are controlled substances classified?
into 5 schedules, schedule 1 has the highest abuse and dependence level and no medical purpose
what are the 2 ways drugs are absorbed?
via enteral (GI tract) or parenteral route
what are 3 drug types that are absorbed via enteral route?
oral,
sublingual,
rectal
what are 5 drug types that are absorbed via parenteral route?
inhalation, injection, topical, transdermal, implant
define bioavailability
% of drug that makes it into systemic circulation
What does volume of distribution tell us?
how extensively a drug is distributed to the rest of the body compared to the plasma
what does a higher Vd mean?
there is more drug in tissue than the blood
what is the difference between first-order and zero order elimination?
first-order has a constant half-life zero order has a constant elimination rate
how many half-lives before a drug is considered “cleared”?
5
how many half-lives does it take to reach “steady state”?
4-5
define steady state as it pertains to dosing
amount of drug excreted in specific time frame = amount of drug administered often equal to time to reach therapeutic effect
Schedule I substance
regarded as having the highest potential for abuse and addiction (THC, LSD, heroin, ecstasy)
Schedule II substance
approved for specific uses but still have a high potential for addiction (opioids/narcotics)
Schedule III substance
lower abuse potential but still might lead to dependence
Schedule IV substance
still lower potential for abuse
Schedule V substance
lowest relative abuse potential
define specificity
drug binds to only one type of receptor
define selectivity
can bind to a multiple subtypes of a receptor but it prefers one
what is Emax?
maximal response receptors are saturated may cause toxicity
what is ED50?
effective dose to get 50% of expected response
how does ED50 relate to potency?
lower ED50 = more potent less drug required for effect
What is a quantal-dose response curve?
used to compare safety of a drug tracks % or # of population who has a particular reponse at a given dose
what can a quantal-dose response curve help us find?
the smallest effective dose among a population of people.
what is TD50?
dose that is toxic for 50% of people
What is the Therapeutic Index?
a ratio of TD50 to ED50
What is the Naranjo Scale/
a questionnaire that helps to determine if a pt is suffering from AE
what are the 3 types of pain?
nociceptive neuropathic psychogenic
What neural structures are involved with ascending pain pathways?
- periphery sensory neurons
- dorsal horn of spinal cord
- brain stem
- thalamus
- somatosensory cortex
What does the descending pathway do?
modulate/suppression pain signals
where does the descending pathway originate?
periaqueductal gray matter of the mid-brain
Name some neurotransmitters in the nociceptive pathways
GABA, glutamate, serotonin, norepinephrine, adenosin
what is the MOA for opioids?
bind to opioid receptor in CNS to inhibit ascending pain pathways
What are the 3 main opioid receptors?
mu delta kappa
AE of opioids on CNS
sedation, nausea, respiratory depression, cough suppression, miosis (pinpoint pupil), truncal rigidity
AE peripheral effects of opioids
constipation urinary retention bronchospasm reduced GI motility Pruritus (itching)
what to notice for respiratory depression
labored breathing and decreased respiration rate
effects associated with Mu opioid receptors
analgesia, euphoria, respiratory depression, bradycardia, emesis, slowed GI motility, pruritis, high abuse/dependence potential
what is nociceptive pain?
produced by injury stabbing, aching, well-localized (exceptions)
when is nociceptive pain not localized?
when it originates from visera
what is neuropathic pain?
typically indicates nerve involvement burning, tingling sensation
what are the 2 primary nociceptive afferent neurons?
unmyelinated C fibers finely myelinated A delta fibers
in the dorsal horn, what neurotransmitters inhibit pain signal propagation?
- NMDA blocker
- substance P antagonists
- inhibition of NO synthesis
what is the substantia gelatinosa?
a collection of gray cells (in dorsal horn) act like gate keeper to regulate pain signals from nociceptive fibers
what are the three subtypes of DMARDs?
- Non-biologic
- Biologic (TNF/Non-TNF inhibitor)
What is the basic MOA for DMARDs?
impacts mediators of inflammatory response
What 3 drugs are Non-biologic DMARDs?
- Methotrexate
- Sulfasalazine
- Hydroxychloroquine
DMARD (biologic TNF Inh) common AE
- headache
- infection
- antibody development
- IV infusion reactions (fever, hypotension, urticaria)
DMARD (biologic TNF In) Boxed warnings
serious infections, secondary malignancies like lymphoma
What is the MOA of Methrotrexate?
unknown, but possibly impacts IL-1, TNF-alpha, leukotreine levels
methotrexate common AE
N/V/D, alopecia, malaise
methotrexate less common AE
- increased liver function tests
- heptatoxicity
- nephrotoxicity
- thrombocytopenia
- bone marrow suppression
Methotrexate PT concerns
- hydration
- photo-sensitivity
- caution: strengthening, stretching, deep tissue work, infection risk
hydroxychloroquine AE
- dyspepsia
- nausea
- abdominal pain
- rashes
- nightmares and visual disturbances
What DMARDs are indicated for lupus?
- methotrexate
- hydroxychloroquine (Plaquenil - also indicated for malaria)
What drug is a Non-TNF inhibitor?
Rituximab
rituximab AE
- injection/infusion reactions
- increased LFTs
- antibody development
What 2 drugs are TNF Inhibitors?
- Adalimumab
- Etanercept
AE TNF inhibitors
headache, antibody development, infection, IV reactions
which DMARDs have boxed warnings?
- Adalimumab
- Etanercept
Opioid drugs
- Codeine
- Hydrocodone
- Hydrocodone w/acetaminophen
- Morphine
- Oxycodone
- Oxycodone w/acetminophen
- Fentanyl
- Hydromorphone
- Meperidine
- Tramadol
- Methadone
what opioid can be perscribed as an antitussive?
codeine
Opioid common routes
PO, rectal, IV, topical, subcutaneous, intrathecal, intranasal, transmucosa, epidural
Opioid MOA
bind to opioid receptors in the CNS to inhibit ascending pain pathways
Opioid AE CNS effects
sedation
nausea
respiratory depression
cough suppression
miosis
truncal rigidity
Opioid Peripheral AE
constipation
urinary retention
bronchospasms
reduced GI motility
pruitis
basic pathophysiology of cancer
uncontrolled cell growth
what is Nadir?
10-28 days when WBC is at it’s lowest, no trx given here
primary treatment (cure) for cancer
- surgery
- radiation
- chemotherapy
- biotherapy
when is adjuvant therapy used?
after primary trx
when is neoadjuvant therapy used?
before primary trx
goals/stages of treatment
- cure
- control
- palliative
what is palliative care?
decrease tumor burden, improve QOL, relieve pain
Types of cancer trx
- radiation
- surgery
- pharmacotherapy,
what is used to treat almost every solid tumor?
radiation
Radiation trx AE
- significant damage to all tissues
- can result in fibrosis of lungs (location dependent)
- fatigue
PT concerns for radiation
fatigue, location of tissue damage
Cancer trx used to maximize tumor eradication
surgery
PT considerations for surgery trx
wound complications, lymphedema, general post-op concerns
what are the 3 types of pharmacotherapy?
- chemotherapy
- targeted therapy
- immunotherapy
what is chemotherapy
drugs that inhibit growth and replication of cancer cells
what is targeted therapy
blocks genes/proteins, specific genetic mutations
what is immunotherapy
hormones and drugs that use the immune system to trx cancer
majority of immunotherapy drugs utilize what?
- antibodies that end in -mab
- interferon
- interleukins (non-specific immunotherapy)
what cancer AE should we be most concerned with?
- thrombocytopena
- neutropenia
- peripheral neuropathy
- pain
- infection
- mouth/throat
special precautions for oral chemotherapy
wear gloves when touching laundry or bodily fluids (specific to the oral med)
NSAID medications
Ibuprofen Naproxen Indomethacin Aspirin Celecoxib Meloxicam Diclofenac Trolamine salicylate
NSAID indications
analgesia antipyretic anti-inflammatory
Aspirin indications
analgesia antipyretic anti-inflammatory antithrombotic
NSAID MOA
reversibly inhibits COX-1 and COX-2 enzymes to decrease prostaglandin formation
how is Aspirin’s MOA different from other NSAIDS?
it irreversibly binds to COX enzymes, other NSAIDs reversibly bind
general NSAID’s AE
N/V, dyspepsia, ulcers, GI bleeding, increased BP, nephrotoxicity, CV risk
what NSAIDs are antithrombotic?
Aspirin
Celecoxib
Diclofenac
Trolamine Salicylate
Meloxicam
If you have GI risk which NSAID is the safest to take?
Ibuprofen (motrin, Advil)
If you are at CV risk what is the safest NSAID to take?
Naproxen
When should you avoid taking Celecoxib?
If you are at CV risk
If you hae CV risk what NSAID should you avoid?
Celexocib
T/F: someone with CHF shouldn’t take NSAIDs because it will increase their fluid retention
TRUE
T/F: NSAIDs blunt the action of cardiovascular drugs?
TRUE
Gabapentin indication
neuropathic pain
Gabapentin drug class
GABA analog, anticonvulsant
Gabapentin MOA
bind to alpha 2-delta subunit of a calcium channel to block its effects
Gabapentin AE
dizziness, drowsiness
Azathioprine drug class
immunosuppresant
Azathioprine indication
- SLE
- off label trx for MS
Azathioprine MOA
decreases the immune response so the body doesn’t attack itself
Azathioprine AE
N/V
Hyaluronate indication
OA
Hyaluronate MOA and AE
- MOA - viscoelastic solution to provide joint lubrication
- AE - injection site rxns, swelling, and rash
anesthetic drugs
- lidocaine
- propofol
anasthetic drugs indications
patient controlled analgesia
general anasthetic common routes
IV, inhalation
regional anasthetic common routes
intrathecal, epidural, inflitration anesthesia, peripheral nerve block, IV, regional block
local anasthetic common routes
injection, topical