test 2 - surgical medications Flashcards
medications related to surgery
nitrous oxide isoflurane propofol fentanyl midazolam procaine and lidocaine rocuronium succinylcholine
balanced anesthesia
using a variety of anesthetics for the best results… to provide sleep, analgesia, elimination of certain reflexes and good muscular relaxation
inhalation anesthetics
gaseous
volatile agents
intravenous anesthetics
hypnotics - barbiturates, short acting
narcotics
other – neuroleptic like
local anesthetics
esters and amides
adjunct anesthetics
skeletal muscle relaxant
how can the dosage of inhalation anesthetics be controlled
controlled by anesthetist
both inhalation and exhalation
type of gaseous general anesthetic
nitrous oxide “laughing gas”
action of nitrous oxide
produce narcosis
analgesia
amnesia to varying degrees (through causing progressive depression of CNS; GABA-receptor agonist, opioid agonist
pharmacokinetics of nitrous oxide absorption distribution metabolism excretion
A: rapid and diffused through alveoli
D: readily passes BBB
M: not metabolized
E: rapid and complete through lungs
ADRs of nitrous oxide
- mostly free of toxicity effects when given WITH OXYGEN
- compromises normal tissue oxygenation if balance not adequate
- toxic suppression of CNS can occur
- post-op nausea and vomiting can occur
special information for nitrous oxide
- greatest use as induction agent
- must be given in combination with oxygen (AT LEAST 30%)
- must be given with other agents, except in very short procedures
volatile anesthetic agents classification
inhaled general anesthetic (volatile liquid)
volatile anesthetic agents overview
more soluble in blood, intercellular fluid and fatty tissue than gaseous anesthetics
slower onset in induction and slower recovery
high solubility can allow tissue and blood concentrations to build up unless carefully titrated
prototype volatile drug
isoflurane (forane)
action of isoflurane
progressive depression of CNS (exact action is unknown)
GABA and glutamate receptor agonist
other effects of isoflurane
hypotension from vasodilation, not cardiac output effects
resp – less efficient exchange of gas; rapid and shallow resp; respiratory depression
muscle – some relxation by central depression
liver – depressed function
pharmacokinetics of isoflurane
A = rapid D = throughout body; crosses BBB onset = 7-10 mins, duration = 7-19 mins M = minimal E = via respiratory (exhaled breath)
ADR of isoflurane
hypotension (from vasodilation)
significant respiratory depression
can “trigger” malignant hyperthermia; especially in conjunction with succinylcholine
special information about isoflurane
relaxes the tracheal area and depresses the reflexes – which simplify tracheal intubation
if alone – is not a potent analgesic… has some mild skeletal muscle relaxant effects… THEREFORE need an agent for quick induction and one for muscle relaxant. If used alone, however, you can see the pt going through stages of anesthesia because of slow onset
PT may shiver coming out of anesthesia
related drugs to isoflurane
desflurane (suprane)
sevoflurane (ultane)
IV anesthetics overview
ADV
rapid, pleasant induction, absence of explosive hazards and low incidence of postop N/V
IV anesthetics overview
DISADV
laryngospasm
bronchospasm
hypotension
respiratory arrest
IV anesthetics overview
uses!!
induce and maintain general surgical anesthesia, basal anesthesia and hypnosis
usually use short-acting and ultra-short acting barbiturates and also narcotics
MAJOR DIFFERENCE BETWEEN BARBITURATES AND GASEOUS AGENTS IS…
SAFETY!!!
inhalation anesthetist controls minute by minute administration and removal
IV once administered, course of events must continue until out of the system
barbiturates classification
IV general anesthetics, ultra short acting
prototype drug for barbiturates:
Propofol (diprivan)
action of propofol (diprivan)
promote the release of GABA
has short duration of anesthesia action
pharmacokinetics of propofol
A: rapid
D: onset = 60 seconds; length of action = 3-5 mins
M = hepatic
excretion = kidney
ADRs for propofol
Respiratory depression, hypotension from vasodilation
risk of bacterial infection (in lipid-based emulsion)
propofol infusion syndrome (rare); injection site pain. Actually has antiemetic properties.
special information for propofol
Induction is smooth, easy, & pleasant for patient.
Not recommended for patients with severe heart disease or respiratory difficulties.
NOT a controlled substance.
Is a milky-white solution (“milk of amnesia”)
commonly used IV anesthetics
etomidate (amidate)
fentanyl/droperidol combination (innovar)
etomidate (amidate) uses
hypnotic agent used for induction of anesthesia; useful for those with heart issues who cannot tolerate propofol since minimal cardiac effects
fentanyl/droperidol combination (innovar) uses
an opioid and neuroleptic combination used for
“neurolept analgesia”
anesthetic dissociative
narcotics use
used as anesthetic as well as preoperatively, and for analgesia
what is fentanyl sublizamaze
- narcotic anesthetic
- prototype drug!
action of fentanyl
Morphine-like action (100 times as potent as morphine)
(See opioid analgesic section of supplement listing Morphine Sulfate)
– opioid agonist
** remember not used to help someone sleep, moreso for pain**
pharmacokinetics for fentanyl
A = for surgery, usually IV so absorption is bypassed used often in surgery/post surgical care
D = diffuse. factor onset than morphine, with short duration
M = liver
E = kidney
RAPID ONSET! VERY SHORT DURATION
how to remember that fentanyl only takes a small amount
think about when people get drugs but they’re laced with fentanyl since it only takes a little amount –> OD
why is absorption bypassed with fentanyl
it is bypassed when given IV since it is going straight into the bloodstream
ADRs of fentanyl
euphoria
miosis (pin-point pupils, might indicate if an unconscious person ODed)
N/V
pruritus (itching)
constipation (key for all opioids)
hypotension
respiratory depression, bradycardia (when people are having surgery, need to pay close attention to resp/cardiac)
what is the black box warning for fentanyl
SIGNIFICANT ABUSE POTENTIAL!!
special information for fentanyl
Rapid IV injection or large doses may cause muscle rigidity & apnea - observe closely!
2. Topical patches (Duragesic) used for analgesia; change q 72 hours for pain control.
3, Also lozenge on a stick (Actiq) and buccal tablets (Fentora)
other neuroleptic like… ex KETAMINE (ketalar)
Categorized as “dissociative” anesthetics.
They induce a trance-like effect characterized by analgesia, quietude, and detachment from the environment without loss of consciousness.
Neuroleptanesthesia is often produced by administration of a neuroleptic agent, a narcotic analgesic, and sometimes nitrous oxide with oxygen.
*Also being used for treatment of Major Depression now
midazolam (versed) classification
IV anesthetic, benzodiazepine
action of midazolam
neuroleptic effect, exact action unknown. Acts on limbic, thalamic, and hypothalamic regions to cause CNS depression and skeletal muscle relaxation. Also prevents seizure activity.
(Probably potentiates GABA (inhibitory neurotransmitter)
pharmacokinetics of midazolam
Absorption- Only given parenterally
Distribution- Diffuse. Does cross the blood-brain barrier and placenta. Peak-half-hour to one hour; half-life 2.5 hrs.
Metabolism- liver
Excretion- kidney
ADRs of midazolam
Respiratory depression (even respiratory arrest)-BLACK BOX, decreased alertness and amnesia (which may last rest of day after administration), hypotension, hiccups, laryngospasm, loss of dexterity. Have reported muscle tremors, tachycardia, shortness of breath.
what is the black box warning for midazolam
RESPIRATORY DEPRESSION, EVEN RESPIRATORY ARREST
special information for midazolam
Usually produces an anterograde amnesic effect (loss of memory about the procedure). Also decreases anxiety.
2. Has a more prolonged post anesthetic recovery period than barbiturates. 3. Other benzodiazepines = diazepam (Valium), lorazepam (Ativan), etc.
types of local anesthetics
short duration - mepivacaine (carbocaine)
lidocaine (xylocaine)
long duration - bupivacaine (marcaine)
action of local anesthetic
Unknown, but is known to stabilize or elevate threshold of excitation of nerve cell membrane without affecting resting potential. This prevents depolarization & transmission of nerve impulses.
pharmacokinetics of local anesthetics
A: VARIES
D
M: procaine by plasma esterase; lidocaine and Marcaine by liver
E
ADRs of local anesthetics
Overdosage or systemic absorption may give ADR’s in CNS = excitement, convulsions, and then CNS depression.
Cardiac = bradycardia, hypotension, cardiac arrest; Others = N/V, pallor, apprehension
special information of local anesthetics
- Loss of all sensation occurs, but pain fibers affected first.
- If it becomes systemic, can have serious reactions–especially heart and brain.
- *Vasoconstrictors are used with them to decrease systemic absorption.
- Topical example – Benzocaine
types of skeletal muscle relaxants
Usually administered to allow for lower dose of general anesthetic to be used.
Two major types: A. Non-depolarizing neuromuscular blocking agents B. Depolarizing neuromuscular blocking agents
classification for skeletal muscle relaxants
Non-depolarizing (competitive) neuromuscular blocking agents.
prototype drug for muscle relaxants
rocuronium (zemuron)
action of rocuronium
prevents acetylcholine from acting by occupying cholinergic receptor sites.
competitive antagonist
pharmacokinetics for rocuronium
Absorption: Is intravenous. Rapid onset of action
Distribution: Does not cross blood-brain barrier or placenta. Length of action 20 – 40 min.
Metabolism: None
Excretion: Largely unchanged by kidney
ADRs of rocuronium
tachycardia, muscle weakness, salivation, hypertension
related drug to rocuronium
vecuronium (norcuron)
how is rocuronium reversed
by anticholinesterase like neostigmine (allows accumulation of ACh) or a newer agent called sugammadex
what classification is succinylcholine (anectine)
REMEMBER THIS IS PROTYPE DRUG!
- depolarizing neuromuscular blocking agents
action of succinylcholine
Repolarization of end-plate does not occur after discharge.
Resembles acetylcholine - but produces more prolonged depolarization of motor endplates–partially due to slower inactivation by cholinesterase.
pharmacokinetics of succinylcholine
hydrolyzed by plasma cholinesterases (pseudocholinesterase)
excreted by kidney
ADRs of succinylcholine
Muscle weakness, bronchospasm, apnea, bradycardia, hypotension, arrhythmias, increased salivation, postop muscle pain, hyperthermia. However, has low level toxicity.
