Flashcards in CFC Deck (106)
what are bethanecol and carbachol?
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?
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?
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?
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
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?
May also be used for ehrlichiosis.
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.