from all cases Flashcards
what is depakote? uses?
- valproate semisodium (valproic acid and sodium valproate)
- antiepileptic
- effective in bipolar disorder and in the prevention of migraine headaches
depakote MoA acute effects
- increases GABA
- decreases neuronal excitability via the blockage of voltage gated Na+ channels
depakote longer-term effects
changes in:
- glucocorticoid, 5-HT and DA neurotransmitter systems
- inositol metabolism and protein kinase C activity
- Wnt/B-catenin cell signalling pathway
- brain lipids and their metabolism
- increased trophic and protecting facets eg. BDNF and the anti-apoptosis factor B-cell lymphoma-2 (Bcl-2)
- class 1 his tone deacetylases (HDAC) inhibition —> altered gene expression
valproate side effects
- LOTS
- very common - nausea, tremor, weight gain
- increases risk of spina bifida x12-16 in pregnant women, also increased risk of cleft palate, autism, postnatal neurodevelopmental problems, atrial septal defect etc
paracetamol use and MoA
- effective analgesic for acute pain
- COX inhibitor
- inhibits prostaglandin synthesis by reducing COX1 and COX2
wha can acute paracetamol overdose lead to?
fatal liver damage
ibuprofen MoA and SEs
- NSAID — reduce tissue inflammation and nociception
- non-selective, reversible inhibition of COX1 and COX2
- reduce prostaglandin synthesis via the arachidonic acid pathway
- the inhibition of COX1 is thought to cause some of the side effects such as GI ulceration
- GI ulceration, GI irritation, renal toxicity, some cardiovascular side effects such as MI and hypertension
gabapentin and pregabalin MoA and SEs
- anticonvulsants used in pain management
- binds to a2d part of Ca channel — decreases subsequent release of excitatory neurotransmitters such as glu, substance P, NE and CGRP
- dizziness, sleepiness, water retention, difficulty walking, upset stomach
tricyclic antidepressant example
amitriptyline
tricyclic antidepressant use MoA
- analgesic and treatment of depression and anxiety-related disorders (used in treatment resistant cases)
- act at presynaptic 5-HT and NA reuptake transporters, increasing the availability of these neurotransmitters
- also block postsynaptic histamine and muscarinic-ACh receptos contributing to many of their side effects
BLOCK SERT AND NAT
amitriptyline side effects
dry mouth, constipation, dizziness, sleepiness, headache, difficulty peeinhg, weight gain, memory impairment
codeine use and MoA
- codeine is an opioid analgesic used to treat moderate to severe pain
- selective for the mu opioid receptor
- opioids reduce pain signal transmission by activating post-synaptic opioid receptors — leads to reduced intracellular cAMP conc, decreased Ca++ influx and thus inhibits the release of several neurotransmitters such as glutamate and substance P
lidocaine MoA
blockage of Na+ channels prevents depolarisation along axons, thus preventing signal propagation
alteplase uses and MoA
- tissue plasminogen activator
- used in stroke — intravenous thrombolysis
- aims to dissolve the thrombus to allow reperfusion
- catalyses the conversion of plasminogen to plasmin, the major enzyme responsible for clot breakdown
aspirin MoA
- inhibits cyclo-oxygenase, which converts arachidonic acid to prostaglandins and thromboxanes
- thromboxane, under normal circumstances, binds platelet molecules together to create a patch over damaged walls of blood vessels. this platelet clump can become too large and block blood flow
- aspirin, an anti-thrombotic drug, is an immediate treatment after an ischaemic stroke to reduce the likelihood of having another stroke
diazepam uses and MoA
- acts on GABA (A) receptor
- allosteric modulator at GABA receptors
- GABA binds between alpha and beta subunits causing Cl- to flow into neurone and hyperpolarise cell — major inhibitory neurotransmitter and is present in 30% of brain synapses
- diazepam binds at separate site between alpha and gamma subunits — this potentiates the action of GABA and increase Cl- influx
- eases anxiety within 0.5-1 hours
name some SSRIs
sertraline, paroxetine, escitalopram, fluoxetine
SSRIs MoA
- block serotonin (5-HT) reuptake from synapse
- increases amount of 5-HT in synaptic cleft
- not addictive, may take 1-2 weeks to start working, effective in 70% of cases
common side effects of SSRIs
nausea, dry mouth, low sex drive, blurred vision, dizziness, loss of appetite, insomnia, sweating
common side effects of diazepam
sedation, respiratory depression, tolerance, dependence, impaired cognition
- shouldn’t be prescribed for more than 4 weeks
statin MoA
- eg. atorvastatin
- competitively inhibit HMG-CoA reductase = rate limiting enzyme in the production of cholesterol in the liver
- reduces liver production of cholesterol —> leads to more LDL receptors
- increased removal of LDL from plasma
- also increase HDL and lower triglycerides
side effects of statins
myosotis, rhabdomyolysis (rapid breakdown of skeletal muscle — causes dark coloured urine — myoglobin released from muscle and ends up in urine — toxic for kidneys — kidney failure), altered liver function tests, complications are rare but lots of people are taking them
what do tricyclic, SSRI and SNRI antidepressants block?
SERT and/or NAT — increase synaptic levels of 5-HT and/or NA
patients on an MAO must stick to what kind of diet?
low tyramine (or could lead to a hypertensive crisis and stroke)
MAO-A vs MAO-B inhibitors use
MAO-A = antidepressants
MAO-B = parkinson’s
name 2 SNRIs
venlafaxine and duloxetine
why are SSRIs safer in overdose than tricyclics?
Like tricyclics these drugs block both reuptake transporters. However, they lack the unwanted binding at a range of receptors that the tricyclics generally have and therefore tend to have fewer side effects and are safer in overdose.
newer antidepressant MoA : mirtazapine
- principally an adrenergic a2 receptor antagonist
- noradrenergic a2R antagonism blocks the -ve feedback whcih is tending to reduce NA release
- net effect is increased NA release
- noradrenergic a2R antagonism also blocks the -ve feedback,c tending to reduce 5-HT release. net effect is increased 5-HT release
main drug is MS treatment
methylprednisolone