CFC Flashcards
what are bethanecol and carbachol?
Choline esters
They are resistent to AChE.
Both have GI tract effects.
HAve been used to induce gastric motility.
Carbachol used topically to induce miosis.
What are muscarine, pilocarpine and arecoline?
Cholomimetic alkaloids
Pilocarpine is used as a topical solution to induce miosis. It is used for the treatment of glaucoma. It is contraindicated in uveitis and anterior lens luxation.
What are physostigmine, neostigmine, edrophonium and pyridostigmine?
They are reversible acetylcholinesterase inhibitors. They have a cholinergic effect initially.
Edrophonium is used for the reversal of on depolarising muscle relaxants and diagnosis of myasthenia gravis. it has a short duration of action.
Neostigmine is used for the reversal of non depolarising muscle relaxants and treatment of myasthenia gravis.
Pyridostigmine is also used for treatment of myasthenia gravis as it has moderate duration.
What are atropine and scolopamine?
Naturally occuring muscarinic antagonists (parasympatholytics).
Atropine can be metabolised in the liver. Used as a premedicant to decrease salivation. Used to treat OP toxicity. not recommended in horses.Can also be used for dilation of the pupil for examination, or used to increase heart rate, used with AChEI to prevent side effects from muscarinic stimulation when these agents used to reverse neuromuscular blockade.
Scoplamine is a naturally occurring agent used for drying secretions, contained in the antispasmodic buscopan, it has anti emetic agents.
What is glycopyrronium bromide?
A synthetic agent which acts as a muscarinic antagonist. It does not cross the placenta or the blood brain barrier. It has less CNS effects and is useful in caesarian sections. Used in ocular surgery to prevent vagal stimulation
What is tropicamide?
A muscarinic antagonist - used as a mydriatic. rapid acting short duration of several hours.
What is ipratopium bromide?
A muscarinic antagonist, used for bronchodilation in horses.
What is pheynylpropanolamine?
An a agonist - most important use is in the treatment of urinary incontinence in the bitch, it is administered orally. it has also been used as a nasal decongestant.
What is Dobutamine?
a B1 agonist - has primarily cardiac effects and will increase heart rate and force of contraction. dubutamine is used in equine anaesthesia to maintain a mean arterial pressure above 70mmHg.
What is Clenbuterol?
A b2 agonist - causes bronchodilation, uterine relaxation, used in the treatment of cOPD in horses, given orally or IV. can induce vasodilation and tachycardia. it also has a growth promotant effect.
What is terbutaline used for?
Also used as a bronchodilator but has more cardiac side effects. can be used as an alternative to propantheline in the medical management of conduction disturbances.
what is isoxuprine?
a b2 agonist - Used in the treatment of navicular disease, it induces vasodilation.
What are phenoxybenzamine and prazosin and what are they used for?
a1 antagonists
They cause relaxation of the urinary sphincter and promote urination.
What are the side effects of NSAIDS?
They are related to the inhibition of Cox1
GIT ulceration due to reduced synthesis of GI prostaglandin. Prostaglandins inhibit gastric acid secretion and promote mucous secretion. large intestinal lesions in horses associated to binding of PBZ to feed.
Nephrotoxicity - effect of inhibition of prostaglandin on renal blood flow as PGS dilate the afferent arteriole and allow activation of RAAS to constrict efferent arteriole.
How does aspirin work?
It irreversibly binds cyclo oxygenase . the side effects are GI erosions, haemorrhage and emesis. it has a selectivity for platelet COX. It is more effective as an antithrombotic agent at low doses.
Why can cats not metabolise paracetamol?
needs to undergo glucuronidation. NabQI binds to glutathione but if glutahione is saturated it binds to hepatic proteins causing necrosis. Treatment is with N-acetylcystine - a precursor of glutathione.
What are the metabolic effects of glucocorticoids?
Increased gluconeogenesis
Inhibit utilisation of glucose > hyperglycaemia
Increased glycogen storage in response
Protein breakdown and reduced synthesis
Redistribtion of body fat
NEgative calcium balance.
Elevation of liver enzymes
Induction of abortion/parturition
alteration of CNs function
mineralocorticoids activity.
Anti inflammatory effects
Decrease function of osteblasts and increase activity of osteoclasts.
Decrease action of T helper cells
Decrease accumulation of leucocytes in areas of inflammation
Decrease fibroblast function -r educe healing and repair
Which steroids are short acting and which are long acting?
Prednisolone, prednisolone, methylprednisolone are all short acting 24h.
Which steroids can be used intra articularly?
Methylprednisolone - rapid metabolism to MP, very low serum concentrations 24 hr, levels maintained for up to 29 days
Triamcinoline acetonide - higher and more prolonged plasma levels, levels in joint undetectable after 2 weeks.
Which drugs can be used to treat coccidia?
Ionophores - eg monensin, salinomycin. The therapeutic index of these is low - especially in horses.
sulphonamides - e.g sulfadimidine, sulfadimethoxine, sulfaquinoxaline. they interfere with folic acid synthesis.
Amprolium- used as a prophylaxis in chickens/turkeys - in feed or drinking water. Poor activity against some intestinal eimeria.
Toltrazuril - targets all stages, used in pigs and poultry for treatment.
diclazuril - used in calves, poultry and lambs for treatment and prophylaxis.
Decoquinate - disrupt coccidial cell transport, mainly for prophylaxis
What is the treatment of babesiosis?
imidocarb.
May also be used for ehrlichiosis.
Also tetracylines
Where is contrast media injected into during myelography?
Into the subarachnoid space which outlines the spinal cord.
What technique of radiography should be used for the thorax?
high kv low mas
What is an interstitial pulmonary pattern?
An unstructured interstitial pattern with ground glass/honey comb appearance.
Ddx - expiration, age related fibrosis, pulmonary involvement in lymphoma, early in pulmonary disease.
If nodular interstitial - pulmonary metastasis, granulomatous lung disease, PIE.
Nodules smaller than 4mm cna not always be seen.
What is a bronchial pulmonary pattern?
Increased opacity of the bronchial walls, abnormal shape and diameter of bronchi, thickening of bronchial walls, tramlines (side on bronchi) and doughnuts (end on bronchi).
ddx - bronchitis, bronchopnuemonia, feline asthma, mineralisation of bronchial walls.
What Is an alveolar pulmonary pattern?
fluffy, ill defined infiltrate + confluence of abnormal areas. focal - lobar - perihilar - generalised, air bronchograms.
ddx - pneumonia, pulmonary oedema, pulmonary haemorrhage, neoplasia
What may you see on radiography of a pneumothorax?
Displaced ung margins collapsed lung lobes defined lobar edge Radiolucency - no lung markings elevated cardiac shadow signs of trauma
What technique should be used for radiography of the abdomen?
Low to medium Kv and high MAs maximises abdominal contrast
expose during expiration
Use a grid if abdominal diameter >10cm
What are the typical ultrasound findings in acute pancreatitis?
Pancreas may be measurably swollen, hypoechoic, may contain solid or cystic masses, mesenteric fat inflamed and hyperechoic.
How does hypercalcaemia occur as a paraneoplastic syndrome?
It is a consequence of deregulation of homeostatic mechanisms between parathyroid hormone, calcitonin and active vitamin D.
Most common causes of hypercalcaemia are;
Malignancy and hypoadrenocorticism in dogs
Malignancy, renal failure or idiopathic in cats.
In non skeletal solid tumours as a result of tumour derived parathyroid hormone related protein and cytokines such as transforming growth factors, tumour necrosis factor and oestrogen functioning as osteoclast activating factors . e.g t cell lymphoma, anal gland adenocarcinoma, thyroid carcinoma, thymoma, malignant melanoma
Increased plasma PTH-rp concentration in a hypercalcaemic patient in the absence of renal failure gives a strong index of suspision for neoplasia.
Sometimes hypercalcaemia results from direct bone destruction in primary or metastatic tumours e.g myeloma, leukaemia, bone tumours, thyroid carcinomas.
What are the main clinical signs of hypercalcaemia in dogs and catS?
In dogs - pupd
in cats - lethargy/anorexia
The severity of signs depennds on the absolute magnitude, rate of rise, underlying cause, duration.
How can hypercalcaemia be treated?
IVFT 0.9% Nacl
Frusemide - causes decreased tubular calcium reabsorption at loop of henle
Corticosteroid - decreases gut absorption, bone resorption and increases renal excretion of calcium.
Calcitonin - decreases bone resorption
Bisphosphonates such as pamidronate, zoledronate and clodronate - bind ca2+ to hydroxyappetite crystals, decrease bone resorption
Sodium bicarbonate - promotes alalosis, increases protein bound calcium fraction
What toxic effects does cyclophosphamide have?
Bone marrow suppression
anorexia
sterile haemorrhagic cystitis
vomiting/diarrhoea
What is chlorambucil used to treat?
Chronic lymphocytic leukaemia.
What are the possible toxic effects of azathioprine? what is this used to treat?
treat immune mediated disease
Bone marrow suppression
Pancreatitis
What are the toxic effects of doxorubicin?
Phlebitis
Bone marrow suppression
anaphylaxis
cardiotoxicity
What are the possible side effects of vincristine and vinblastine?
Phlebitis, peripheral neuropathy
vinblastine is myelosuppressive
Why is prednisolone used for lymphoma?
It is lymphotoxic and anti inflammatory which allows tumour shrinkage
What are the side effects of cisplatin? what is it used to treat?
Osteosarcoma
nephrotoxic
should never be given to cats - pulmonary oedema
vomiting after infusion
What are the possible side effects of L asparaginase?
anaphylaxis
Describe the staging for lymphoma?
I - a single node
II - two or more nodes in an affected regional area
III - generalised lymph node involvement
IV - stage III plus liver and spleen involvement
V - bone marrow and non lymphoid organ involvement such as eye, CNS, lung
What is the best treatment for low grade lymphoma in a cat?
Oral prednisone and chlorambucil