3a: Sedative-Hypnotics, Antianxiety, Antidepressants Flashcards
purpose of CNS drugs
to modify the activity of the neurons in the CNS, treat CNS disorders, and change the arousal levels of the CNS
neurotransmitters
released by neurons to cause excitation or inhibition to other neurons
examples of neurotransmitters in the CNS
ACh, monoamines, amino acids, peptides
mechanism of CNS drugs
modification of the synaptic transmission, which is done by altering the quantity of the neurotransmitter
two categories of Sedative-Hypnotics
benzodiazepines and nonbenzodiazepines (both used to promote sleep, specifically in short-term situations like hospital stays)
benzodiazepines
used for anxiety and promoting sleep, considered safer than barbiturates (nonbenzos), less chance of lethal overdose, and can cause tolerance and physical dependence with long-term use
mechanism of benzos
increased inhibition at the CNS synapses that use GABA
side effects of benzos
drowsiness, decreased motor performance, hang-over effect, anterograde amnesia
suffix for benzos
(-am)
nonbenzodiazepines (barbiturates)
used for sleep-hypnosis, CNS depressants, very small therapeutic index, very addictive, not commonly used
mechanism of barbiturates
not entirely clear but do bind to GABA receptors
side effects of barbiturates
very addictive, drug abuse, hang-over effect
suffix for barbiturates
(-al)
other compounds that can cause sedation-hypnosis
alcohol, antihistamines, antidepressants, antipsychotics, anticonvulsants, opioid analgesics
pharmacokinetics of sedation-hypnosis drugs
very lipid-soluble, administered orally one dose at bedtime, absorbed from the GI tract, distributed uniformly throughout the body, metabolized in the liber, excreted through the kidneys
side effects of all sedative-hypnotics
tolerance and dependence, complex motor behaviors (sleep walking, sleep driving, etc.), GI discomfort, dry mouth, sore throat, muscular incoordination
indications for anti anxiety drugs
generalized anxiety, social anxiety, panic disorder, OCD, PTSD
what is the most common benzo for treating anxiety?
Valium
Valium is not good for what population, and why?
not good for the elderly, because it has a long half-life, and they cause sedation, confusion, and memory problems (associated with increased fall risk and hip fractures)
what is rebound anxiety (related to benzos)?
removal of benzo that causes anxiety levels to return to pre-treatment levels
mechanism of BuSpar
increases the effects of the neurotransmitter serotonin
side effects of BuSpar
headache, dizziness, nausea, restlessness, hypothermia, low risk of abuse
why are antidepressants an effective way to treat anxiety?
they typically have fewer side effects and lower risk of addiction than anti-anxiety medications
examples of antidepressants
Paxil, Effexor, Zoloft
indications for beta-blockers
arrhythmias, hypertension, and other cardiac issues (decreases anxiety without the sedation)
symptoms of depression
inappropriate disposition, feeling unreasonably sad or discouraged, fluctuating between periods of depression and excessive excitation
biological cause of depression
disturbance in CNS neurotransmission involving neurotransmitters serotonin, norepi, dopamine
four categories of antidepressants
SSRIs, SNRIs, tricyclics, MAOs
what is the key neurotransmitter that helps regulate mood and depression?
serotonin
mechanism of SSRIs
block the reuptake of serotonin into the presynaptic terminals (allowing serotonin to stay in the synaptic cleft and exert its effect longer)
mechanism of SNRIs
same as SSRIs, but also blocks reuptake of norepinephrine
mechanism of tricyclics
block reuptake of all three synapses: serotonin, norepinephrine, and dopamine
mechanism of MAO inhibitors
prevents MAO enzyme from breaking down neurotransmitters, therefore keeping neurotransmitters in the synaptic cleft for longer
pharmacokinetics of antidepressants
- typically administered orally
- small dosages initially, increased slowly
- metabolized in liver
side effects of antidepressants
most common: nausea, vomiting, diarrhea, constipation
less common: anticholinergic, cardiac effects, orthostatic hypotension
What is the most serious side effect of SSRIs and SNRIs?
serotonin syndrome
mechanism and symptoms of serotonin syndrome
excessive serotonin built up in brain can lead to sweating, restlessness, tremor, clonus, rigidity, progressing to seizures, coma, death
what else are antidepressants used to treat?
chronic pain
what is the primary drug used to treat bipolar disorder?
lithium
side effects of lithium
possible toxicity (since lithium is not metabolized, only excreted in urine)
four systems affected by lithium toxicity
CNS, GI, CV, renal
rehab implications of antidepressants
- 2-4 week delay from start until effects
- depression may increase during this time
- 1/3 of patients with depression do not respond to meds
