Pharm ch. 14

Pharmacology of the CNS

: Study of drugs affecting the brain and spinal cord

CNS main functions

: Controls motor function, sensation, cognition, memory, emotions, and autonomic functions

Cerebrum function

: Motor control, interpretation, memory, feelings, reasoning

Diencephalon function

: Thalamus = sensory relay; Hypothalamus = homeostasis control

Midbrain function

: Eye movement, auditory and visual processing

Pons function

: Sensory relay and respiratory rhythm control

Medulla oblongata function

: Controls autonomic functions (breathing, heart rate)

Cerebellum function

: Coordinates movement and proprioception

Why CNS knowledge matters in respiratory care

: Brainstem controls breathing, airway reflexes, and consciousness

Drug effects on CNS

: Enhance, prolong, or block neurotransmitters; alter synthesis/release

Analgesia

: Pain relief without loss of consciousness

Analgesic

: Drug that reduces or eliminates pain

Antidepressant

: Drug that treats depression by altering neurotransmitters

Antipsychotics

: Treat psychosis; affect dopamine; can cause movement disorders

Antipyretic

: Drug that reduces fever

Anxiolytic

: Drug that reduces anxiety

Conscious sedation

: Relaxed, responsive, maintains airway and breathing

Equianalgesic doses

: Equivalent pain-relief doses between drugs

Extrapyramidal symptoms (EPS)

: Tremor, rigidity, akathisia, dystonia

General anesthetic

: Causes complete loss of consciousness and reflexes

Hypnotic

: Drug that induces sleep

Sedative

: Calms patient, may cause drowsiness

Stimulant

: Increases CNS activity and alertness

Tardive dyskinesia

: Irreversible movement disorder from long-term antipsychotic use

Uricosuria

: Increased uric acid excretion in urine

Sedative effect

: Calming, decreased CNS activity

Hypnotic effect

: Promotes sleep

Anxiolytic effect

: Reduces anxiety

Barbiturates definition

: Powerful CNS depressants

Barbiturate uses

: Sedation, hypnosis, anesthesia induction, seizure treatment

Barbiturate mechanism

: Bind GABAA receptors → CNS depression

Barbiturate metabolism

: Liver

Barbiturate characteristic

: Redistribution

Benzodiazepines definition

: Common sedative-hypnotics and anxiolytics

Benzodiazepine advantages

: Safer, fewer side effects, less addiction than barbiturates

Benzodiazepine mechanism

: Enhance GABA effects

Common benzodiazepines

: Diazepam, lorazepam, midazolam, alprazolam, clonazepam, temazepam, triazolam, chlordiazepoxide

Alcohol mechanism

: Enhances GABA, inhibits excitatory neurotransmitters

Alcohol short-term effects

: Headache, nausea, confusion, thirst

Alcohol long-term effects

: Dementia, hepatitis, reflux

Psychopharmacology definition

: Use of drugs to treat mental disorders

Psychopharmacology conditions treated

: Schizophrenia, bipolar disorder, depression

Psychopharmacologic drug classes

: Antipsychotics, antidepressants, mood stabilizers, stimulants, anxiolytics

First-generation antipsychotics (FGAs)

: Treat psychosis but cause EPS and sedation

FGA mechanism

: D2 receptor antagonists

Examples of FGAs

: Haloperidol, chlorpromazine, fluphenazine, thioridazine, loxapine

Second-generation antipsychotics (SGAs)

: Fewer EPS, act on dopamine and serotonin

Examples of SGAs

: Clozapine, risperidone, olanzapine, quetiapine, ziprasidone, aripiprazole

Depression cause

: Changes in norepinephrine, serotonin, dopamine

Antidepressant classes

: SSRIs, SNRIs, TCAs, MAOIs

SSRI mechanism

: Block serotonin reuptake

SNRI mechanism

: Block serotonin and norepinephrine reuptake

Bupropion mechanism

: Blocks norepinephrine and dopamine reuptake

TCA mechanism

: Block norepinephrine and serotonin reuptake; affect other receptors

MAOI mechanism

: Inhibit monoamine oxidase → increase neurotransmitters

Antidepressant onset

: Initial 3 weeks, max 6 weeks

Lithium use

: Bipolar disorder

Lithium mechanism

: Increases serotonin and norepinephrine reuptake

Valproic acid mechanism

: Enhances GABA

Carbamazepine use

: Second-line bipolar treatment

CNS stimulants

: Increase norepinephrine and dopamine

Stimulant mechanisms

: Increase release, block reuptake, stimulate receptors

Stimulant use

: ADHD

Examples of stimulants

: Amphetamines, methylphenidate

Focal seizures

: Affect one area of brain

Generalized seizures

: Affect entire brain

Types of generalized seizures

: Absence, tonic-clonic, myoclonic, atonic

Antiepileptic drugs

: Phenytoin, carbamazepine, valproic acid, levetiracetam, phenobarbital, topiramate, ethosuximide, lacosamide

Opioid analgesics

: Treat moderate-to-severe pain

Non-opioid analgesics

: Treat mild-to-moderate pain

Pain scale

: 0-10 rating

Opioid mechanism

: Act on mu receptors

Opioid effects

: Pain relief and euphoria

Opioid adverse CNS effects

: Sedation, confusion, miosis

Opioid GI effects

: Nausea, vomiting, decreased motility

Opioid respiratory effects

: Decreased rate, tidal volume, respiratory arrest

Opioid cardiovascular effects

: Orthostatic hypotension

Opioid skin effects

: Itching, redness

Opioid GU effects

: Urinary retention, decreased libido

Opioid tolerance

: Need higher doses

Opioid dependence

: Withdrawal symptoms when stopped

Natural opioids

: Morphine, codeine

Semisynthetic opioids

: Hydrocodone, oxycodone, hydromorphone

Synthetic opioids

: Fentanyl, methadone, meperidine

Agonist-antagonist opioids

: Buprenorphine, nalbuphine, pentazocine

Opioid antagonists

: Naloxone, naltrexone

Naloxone use

: Reverses opioid overdose

Naloxone forms

: IV and intranasal

Non-opioid analgesics

: NSAIDs, acetaminophen, salicylates

NSAID mechanism

: Inhibit COX → decrease prostaglandins

NSAID effects

: Analgesic, anti-inflammatory, antipyretic

Common NSAIDs

: Ibuprofen, naproxen, aspirin, diclofenac, ketorolac

NSAID adverse effects

: GI upset, bleeding, renal dysfunction, hypertension

Acetaminophen use

: Pain and fever

Acetaminophen mechanism

: Weak COX inhibition

Acetaminophen advantage

: Fewer GI side effects

General anesthesia definition

: Loss of sensation and consciousness

General anesthetic mechanism

: Enhance GABA → CNS depression

Inhaled anesthetics

: Nitrous oxide, isoflurane, sevoflurane, desflurane

Inhaled anesthetic route

: Inhaled and absorbed into bloodstream/brain