pharmacology Flashcards
what is skeletal muscle innervated by
motor neurons
what is transmitted at the neuromuscular junction of skeletal muscle
acetylcholine
some features of the neuromuscular junction of skeletal muscles
terminal boiton + surrounding schwann cell, synaptic vesicles, synaptic cleft, end plate region
what chose choline + acetylCoA make
Ach
what does calcium binding to vesicle membanes allow
it to fuse membrane and release Ach
what does calium binding to vesicle membranes lead to the activation of
post junctional nicotinic Ach receptor
what hydrolyses Ach
acetylcholinesterase
what are the products of the hydrolysis of Ach
choline and acetate
what shape are nicotinic Ach receptors
pentameric
when is the nicotinic Ach receptor gate closed
in absence of Ach
when does the nicotinic Ach receptor gate open
when 2 molecules of Ach bind to exterior
what does the opening of Ach nicotinic receptor cause
Na influx and K efflux
at resting potential what has the biggest driving force Na or K
Na
what is end plate potential
a depolarisation when the influx of Na is greater than the efflux of K
what can reduce the amplitude of EPP
drugs or toxins
what does a reduced EPP amplitude mean
skeletal muscle paralysis
how does action potential go deep into muscle fibres
through T tubules
what does action potential going deep into muscle fibres cause
the release of Ca2+ in SR which combines with troponin at bridges to cause contraction
what is the target of therapuetics (anti-cholinesterases)
AchE
what do therapeutics that act on AChE fo
reversibly block their action and some nerve gases used in warfare can act irreversibly
what is neuromyotonia also known as
NMT or Isaacs syndrome
what is neuromytonia
antoimmune disease causing reduced K conductance in motor neurones causing hyperexcitability
what is lambert eaton myasthenic syndrome (LEMS)
autoimmune, reduced Ca conductance presynaptically - decreased Ach causing muscle weekness
what is LEMS associated with
small cell carcinoma of the lung
what is botulism
caused by botulism toxin decreases rease of ACh causing paralysis
what can botulinum toxin be used to treat
over active muscles
what is Myasthenia gravis
autoimmune reduced number of nAChRs muscle weakness causes reduced amplitude of EPP
what are curare like compounds
competitive antagonists of nAChRs, reduces EPP to below threshold for muscle AP generation
where are curare like compounds used
in surgery to produce reversible paralysis
examples of curare like compounds
vesuronium and atracurium
what is pain
an unpleasant sensory and emotional experience associated with actual tissue damage or described in terms of such damage
what type of pain is nociceptive pain
adaptive
what type of pain is inflammatory pain
adaptive
what type of pain is pathological pain
maladaptive
whta re niciceptors activated by
intense stimuli
examples of intense stimuli
thermal mechanical and chemical
what are nociceptors
adaptives
what do nociceptors have
a high threshold
what d nociceptors serve as
an early warning system to detenct and minimise contact with damaging stimuli
wha do nociceptors cause
pain, autonomic response and withdrawal reflex
what type of pain is inflammatory pain
inflammatory and protective
what is inflammatory pain caused by
activation of immune system in injury or infection
what type of pain does inflammatory pain cause
sponteneous and hypersensitivity
what promotes repair in inflammatory pain
low threshold and tenderness
how is inflammatory pain protective
assists in healing of a damaged body part by discouraging physcial contact and movement
what type of pain has no protective function
pathological (maladaptive pain)
what are the types of pathological pain
neuropathic and dystfunctional
what type of pain does pathological pain cause
sponteneous pain and pain hypersensitivity
what causes neuropathic pain
nerual lesion, positive negative symptoms and peripheral nerve damage
what type of pain causes dysfunctional pain
spontaneous pain and pain hypersensitivity
what are the 2 types of nociceptor
A and C fibres
what are the A fibres used for
first or fast high intensity pain
what are C fibres used for
second less intense pain
what functions do peptidergic C fibres have
efferent and afferent functions
what is released in from free nerve endings in neurogenic inflammation
peptides (S and CGRP)
why are peptides released from free nerve endings in neurogenic inflammation
due to tissue damage or inflammatory mediators
what does Sp cause
vasodilation, release of histamine and sensitise surrounding nociceptors
what does CGRP cause
vasodilation
what does the release of peptides lead to
hyperalgesia and allodynia
what is hyperalgesia
increased sensitivity to pain
what is allodynia
triggering of pain sensation from stimuli whcih doesnt normally cause pain
neuropathic pain perceptive
shooting numbness
examples of dysfuncional pain conditiosn
fibromyalgia, IBS, tension headache, temporomandibular joint disease, interstitiyal cystitis
what is not effective in pathological pain
simple analgesics
how to treat pathological pain
anti depressants and anti epileptics
what can be felt as referred pain
deep or visceral pain
what pain is not usually referred
pain originating in superficial structures is not referred
step 1 pain
paractamol, NSAIDs
step 2 pain
codeine
step 3 pain
morphine
NSAID examples
ibuprofen, naproxen, dclofenca, indomethacin, etodolac, celecoxib
indications for NSAIDs
inflammatory arthritis, mechanical MSK pain, pleuritic/[ericardial pain
potential side effects of NSAIDs
dyspepsia, oesophagi’s, gastritis, peptic ulcer, small/large bowel ulceration, renal impairment, increased CVS events, fluid retention, wheeze, rash
newly diagnosed RA what is the best treatment
methotrexate
when ti start DMARDs in RA
within 3 months of symptoms
DMARDs of choice
MTX, SPX
is methotrexate safe in pregnancy
no
adverse affects of DMARDs
thrombocytopenia, hepatitis, pneumonitis, rash/mouth ulcers, nausea and diarrhoea
what to prescribe along with methotrexate
folic acid
SE of sulfalazien
neutropenia
SE of HCQ
retinopathy
what are biologics
drugs used to target specific parts of the immune system affected in inflammatory arthritis
what is more effective than DMARDs
biologics
what are anti TNF used in
RA, PA, AS
examples of anti TNF
etanercey, adalimumab, certolizumab, infliximab, golimumab
what is rituximab
monoclonal antibody against B cells
what does tocilizumab do
inhibits IL6
how to treat acute flare of gout
NSAIDs, corchincine and steroids
se of corchinicne
diarrhoea
gout prophylaxis
allopurinol, febuxatsat, uricosurics
what is allopurinol
xanthate oxidase inhibitor
se of allopurinol
rash, boen marrow toxicity
what is febuxastst
xanthine oxidase inhibitor
who to not give febustat to
people with heart disease
adverse effects of corticosteroids
centripetal obesity, muscle wasting, skin atrophy, osteoporosis, diabetes, hypertension, cataract glaucoma, immune suppression, renal suppression
