Medications for anesthesia, neurological conditions, and psychiatric conditions Flashcards
Anesthetics, Sedative-Hypnotics and analytics, Affective Disorders and Psychiatric Disorders, Anti-epileptics, Drugs for PD, Drugs for MS
Distinguish difference between general and local anesthetics
General is fully body with a patient unconscious whereas local is injected into one area and the patient is still awake
What is induction stage I of general anesthesia
Analgesia:
- pt loses somatic sensation but is still conscious and aware of what is happening
What is induction stage II of general anesthesia
Excitement (delirium):
- pt unconscious but agitated/restless
- want to move quickly thru this to stage III
List different types of general anesthesia and adjuvant medications used during anesthesia
- Pre-op Meds for relax and reduce post op N/V
- Neuromuscular blockers (nondepol and depolarizing)
List some IV anesthetics
- Barbiturates
- Benzodiazepines
- Opioid Analgesics
- ketamine
[- propofol - etomidate
- dexmedetomidine]
How do barbiturates work
CNS depressant to decrease anxiety and facilitate induction of anesthesia used in IV anesthetics
How do benzodiazepines work
CNS depressant to decrease anxiety and tension and provide sedation and amnesia used in IV anesthetics
How do opioid analgesics work
They provide analgesia, antianxiety and sedative effects used in IV anesthetics
How does ketamine work
It produces a dissociative anesthesia that does not cause respiratory or cardiac issues but can cause hallucinations and other rxns during recovery used in IV anesthetics
What is dexmedetomidine
It is a newer IV anesthetic used mostly for ST ICU to stimulate certain alpha receptors in the brain
What is the pharmacokinetics of general anesthetics
- IV metabolized in liver and eliminated in kidneys
- inhaled: metabolized and eliminated in the lungs
What is a concern w/anesthetic if a person has liver or lung disease
It will take longer for it to be eliminated causing longer periods of confusion, disorientation and lethargy
Age concerns w/pharmacokinetics of general anesthesia
- older adults need smaller doses
- difficult w/children since their organs are immature and they have small body masses
What is the mechanism of action of general anesthesia
- Increases inhibition in the CNS by exciting GABA and glycine
- Decreases excitation by acting on K+, ACh, NMDA and opioids
In general, how do anesthetics exert their effects?
By binding to receptors in the CNS
What are the types of pre-operative meds given w/general anesthesia
- sedatives
- anti N/V
- decrease bronchial secretions
- dec gastric acidity (help w/N/V)
- post-op pain (opioids and steroids)
What are neuromuscular blockers
Adjuvants to general anesthesia that increase skeletal mm paralysis to allow for safe surgery
What are the side effects of neuromuscular blockers
tachycardia, increased histamine release, hyperkalemia, residual mm pain and weakness, anaphylaxis
Nondepolarizing blockers vs depolarizing blockers (neruomuscular)
Nondepol last longer by acting as competitive antagonists of post synaptic recetor ro prevent ACh from binding whereas depol is more short term since it acts like ACh and binds and stimulates receptor to depol it so it cant contract
What are the rehab concerns of general anesthesia
- lingering effects (woozy, confused) esp in older adults
- bronchial secretions in lungs
- LT effects on mem and cognition in older adults and those w/cognitive disorders
What is the goal of local anesthesia
To block afferent NT along the periph nerve
What are some advantages of local anesthesia
- rapid recovery
- lack of residual effects
- does not interfere w/CV, pulm, or renal function
- beneficial for childbirth
What are some disadvantages of local anesthetics
- takes longer to achieve effects and there is a risk that analgesia will be incomplete or insufficient
What are the two main categories of local anesthetics
esters and amides
What drug is often co-administered w/local anesthetics and why
A vasoconstrictor so that the anesthetic does not travel out of the target tissue
What is the pharmacokinetics of local anesthetics
- metabolized in liver and blood stream
- excreted in the kidneys
what are the clinical uses of anesthesia (list)
topical transdermal infiltration anesthesia peripheral nerve block central nerve block sympathetic block
What is topical anesthetic
A local anesthetic applied directly to the skin surface, mucous membrane or cornea to allow for symptomatic relief of minor irritations and injury and can reduce pain before minor surgical procedures
What is transdermal anesthetic
A local anesthetic applied to the surface of the skin via patches that can be enhanced w/ionto or phonophoresis to treat tendons, bursae or soft tissue
What is infiltration anesthetic
A local anesthetic where the drug is injected directly into the select tissue and diffuses to sensory nerve endings w/in that tissue –> good for suturing lacerations
What is peripheral nerve block anesthetic
a local anesthetic injected close to the nerve trunk of a peripheral nerve so that transmission is interrupted-> can sometimes be a continuous nerve block where they insert a catheter near the nerve
What is central nerve block anesthetic
A local anesthetic that is injected w/in the spaces surrounding the SC or win the SC but there is a higher risk of Neurotoxicity
What is sympathetic blockade anesthetic
a local anesthetic that selectively interrupts sympathetic efferent DC w/the goal to disrupt outgoing sympathetic signals
What is sympathetic blockade anesthetic useful for
complex regional pain syndrome (CRPS)
What is the mechanism of action of local anesthetics
Disrupt the Na+ channels along the periph nerve so that the message cannot be transferred down further
What are the systemic effects of local anesthesia
CNS toxicity (ringing in ears, agitation, dec sensation) or cardiac toxicity (bradycardia, fatigue, dizziness)
What are the rehab concerns of local anesthetics
- keep a lookout for transdermal patches as you don’t want to heat it (will infuse too fast)
- if continuous nerve block will lack sensation and possible motor control
What are sedative hypnotics
Drugs that promote sleep, esp in acute or ST situations
What are the two categories of sedative hypnotics
Benzodiazepines and non-benzodiazepines
List some other uses of sedative-hypnotics
- anti-anxiety
- sedation and amnesia
- seizure treatment
- control of withdrawal
- mm relax
What are affective disorders
characterized by marked disturbances in a person’s mood - very common in society
What are two types of affective disorders
Depression
Bipolar Disorder
What is depression
General dysphoric mood and lack of interest in previously pleasurable activities that can lead to recurrent thoughts of death and suicide
How can depression be classified
- type
- duration
- intensity of symptoms
What are the 3 factors that contribute to depression
Environmental, biochemical, and genetic
What is the pathophysiology of depression
Disturbance in amine neurotransmitters (serotonin, norepinephrine, and DA)
What are the amine NTs
- serotonin
- norepinephrine
- dopamine
List the two theories of how the pathology of depression occurs
Receptor sensitivity theory
neurogenesis theory
What is the receptor sensitivity theory
- Depression causes a supersensitivity to amine NT
- Antidepressants enhance the stimulation of pre and postsynaptic receptors
- Receptor sensitivity decreases to a more balanced level (takes about 2-3 weeks)
What is the neurogenesis theory
- When people are depressed, they grow less neurons and receptors
- Drugs promote regrowth so there is increased influences of the amines
List some anti-depressant drugs
- SSRI (selective serotonin reuptake inhibitors)
- SNRI (serotonin-norepinephrine reuptake inhibitors)
- tricyclics
- MAOI
What are Selective Serotonin Reuptake Inhibitors (SSRIs)
Antidepressant that block enzyme responsible for the re-uptake of serotonin back into the presynaptic terminal so that more remain in the synaptic cleft –> people are happier
What is the most common antidepressant
SSRI