PHARMACODYNAMICS Flashcards
dopamine hypothesis
biogenic amine hypothesis
dop- psychosis caused by dopamine overactivity in mesolimbic system
biogenic amine- seretonin is the biogenic amine neurotransmitter associated with depression- downregulation or decreased sensitivity of B-adrenergic receptors
glutamatergic hypothesis
NMDA receptor antagonists (e.g ketamine and PCP) induce both +ve and -ve symptoms of schizophrenia in healthy volunteers
4 EPSEs
+ treatments
- dystonia - muscle spasm, occulogyric crisis Tx- anticholinergics
- Pseudo-parkinsonism- tremor, Tx reduce dose, prescribe antichonlinergic
- akathasia - restlessness Tx- reduce dose,
- tardive dyskinesia - lip smacking, Tx- reduce dose. + tetrabenzene
best antipsychotic in liver failure?
Amisulpride /sulpiride
how does chronic lithium use cause diabetes insipidus?
Interference with the action of ADH on its receptors located in the principal cells of collecting ducts in kidney = inability to concentrate urine –> polyuria and polydipsia.
best antidepressant in liver failure?
Sertraline
Citalopram
Paroxetine
Vortioxetine
(best avoid TCA and MAOI)
Histamine H1 blockade
Alpha 1 blockade
Muscarinic central M1 blockade
Muscarinic peripheral M1 blockade
H block- Weight gain, sedation
Alpha 1 blockade - Orthostatic hypotension, sedation, sexual dysfunction, priapism
Muscarinic central M1 blockade - Agitation, delirium, memory impairment, confusion, seizures
Muscarinic peripheral M1 blockade - Dry mouth, ataxia, blurred vision, narrow angle glaucoma, constipation, urinary retention, tachycardia
CYP2D6 shows the largest phenotypic variation amongst the cytochromes
CYP1A2 is involved in metabolism of clozapine.
(caucasion highest frequency)
Grapefruit juice inhibits
Grapefruit juice inhibits
CYP1A2 and therefore can increase clozapine levels.
CYP3A4 and CYP1A2
Tobacco induces CYP1A2
Tobacco induces CYP1A2 and so lower clozapine levels.
which is involved in metabolism of clozapine.
CYP1A2
Varenicline tartate MOA?
partial nicotinic agonism
recommended by NICe to aid in smoking cessation
competes with nictotine at receptor and reduces dopaamnergic reward
high 5HT2/high d2 activity is typical of ?
atypical antipsychotics
causes of anorgasmia?
increased seretonin (1 +2)
raised prolactin
A-1 blockade
drug used to treat anorgasmia caused by SSSRIs?
Cryptohepatadine = antihistamine - antagonist H1 receptors
chronic administration of TCA causes down regulation of?
Beta- adrenergic receptors = might explain therapeutic effects
disulfram acts on
aldehydate dehydrogenase
trazadone MOA
mixed seretonin antagonist/agonist
Benzodiadepines work via
GABA a receptor complex
weight gain caused by clozapine related to?
5HT2-C (CHUBBY)
MAO A preferentially breaks down?
MAO B Preferentially breaks down?
A- prefers seretonin and noradrenaline
B- prefers dopaine, histamine
which antidementia drug also acts on nicotinic receptor?
Galantamne
Galatamine - GI effects most (nicotinic effetcs too)
noradrenalien reuptake inhibitor example
Reboxitine
Atomoxetine
contraindication for paroxetien due to anticholingeric side effects?
acute and chronic narrow angle glaucoma
treatment for MAO crisis
phentolamine or chlopromazine - a-adrenergic antagonist
SSRI high concentration in breast milk?
fluoxetine
TCA with highest antihistaminic activity?
TCA with highest toxicity in overdose?
Doxepin
Dothiepin
which SSR associated with erectile dysfunction. more often than other SSRIs
paroxetine (shortest half life, shortest sexual libedo)
QTC prolongation antipsychotic
sudden death
halpperidol
Thioridazine = sudden cardiac death
what is not a dose dependent effect of clozapine?
agranulocytosis
