Psychiatric disorders Flashcards
4 classifications of hypnotics
- benzodiazepines
- anti-histamines
- miscellaneous
- barbiturates - old fashioned
how does drug induced sleep effect NREM + REM levels
increases NREM, decreases REM
5 actions of benzodiazepines
- hypnotic
- anxiolytic
- anticonvulsant
- muscle relaxant
- amnesic
which of these BDZ has the longest half life:
tempazepma
loprazolam
nitrazepam
nitrazepam - used for early morning wakening
3 sites of action of BDZs
- reticular limbic system RAS - control alertness (hypnotic)
- limbic system in cortex - controls emotion (anxiolyitc)
- other sites of cortex - anticonvulsant
MOA of BDZ
increase GABA - so reduce function in certain brain pathways
if medazolam and methadone are taken together what may happen?
respiratory arrest
drug used for BDZ reversal?
flumazenil
MOA of antihistamines
H2 blockers produce CNS depression
what antihistamine is used in children
promethazine
what are Z drugs and at what receptors do they work?
hypnotics - non-BDZ but work at BDZ receptors
4 main types of anxiolytics
- alcohol
- BDZs
- buspirone
- beta blockers
which BDZ reduces alcohol/drug withdrawal
chlordiazepoxide
when are buspirone used
short term anxiety control for specific reason - does not cause sedation, acts as serotonin agonist
no withdrawal
causes dry mouth
which BDZ in dental formulary?
temazepam + diazepam (plus flumazenil)
what is the difference between hypochondriasis + somatisation?
hypochondriasis = focuses on underlying disease somatisation = focuses on symptoms
psychogenic pain characterisitcs:
inconsistent with anatomical landmarks investigations negative continuous prevents sleep but doesn't wake up analgesia ineffective associated with emotional factors
what causes korsakoffs psychosis?
B1/thiamine deficiency most commonly associated with chronic alcoholism
3 positive neurotransmitters
adrenaline, noradrenaline, dopamine
3 negative neurotransmitters
serotonin, GABA, dopamine
where does serotonin act?
cerebral cortex
how does fluoxetine improve mood?
blocks re uptake of serotonin
dopamine acts on 4 pathways in which part of brain?
frontal cortex
which neurotransmitter is responsible for reward/motivation?
dopamine
which neurotransmitter mediates arousal?
noradrenaline
where are antipsychotics metabolised?
liver
which neurotransmitter do APs effect and how?
dopamine - increase
decrease chloinergics
how do APs effect alcohol + anxiolytics?
increase sedation
APs - 4 dentally relevant things to be aware of
EPS
xerostomia
sedation
postural hypotension
first choice drug therapy for depression?
SSRIs
what guidance should be followed to deal with depression?
NICE CG 90 2009 - depression in adults
NICE CG 91 depression in adults with chronic health problems
simple MOA for antidepressants?
increasing monoamines
4 categories of ADs
SSRIs - selective serotonin inhibitors
SNRIs - selective noradrenaline reuptake inhibitors (3rd line)
TCA - tricyclic antidepressants
MAOIs - monoamine oxidase inhibitors
what happens if you take SSRIs + SNRIs together?
serotonin syndrome - pyrexia
MOA of SSRIs
block re-uptake of serotonin in pre-synaptic cleft
as well as depression, SSRIs may be used for what conditions?
chronic pain e.g. burning mouth syndrome
what SSRI is used for burning mouth syndrome?
paroxetine
how do SSRIs effect sedation?
decrease sedation
why is the MOA of TCAs considered dirty?
non-selective:
targets re uptake of both serotonin + Noradrenaline
causes antihistaminergic activity (sedation)
blocks Na K + Ca channels (decrease pain)
enhances GABA peripherally
3 disadvantages to TCAs
side effects - (xerostomia)
dangerous in overdose
2-3 weeks before effective
MAOIs MOA
block monoamine oxide enzyme which degraded monoamines - so increases MA levels
symptoms + cause of MAOI crisis?
hypertension + headache
dietary intake of monoamine (tyramine rich foods) high + MAOI
xs monoamines
