Pharmacology Credit 2 Revision

Chemically, what are adsorbents?

water insoluble, inert substances

Compare alfentanil to fentanyl

less potent; eliminated in a metabolically similar way

Compare sufentanil to fentanyl

5-7 times more potent; eliminated in a metabolically similar way

Compare the duration of action of non-selective β-receptor agonists and β2-selective agonists?

non-selective β-receptor agonists are short-acting
β2-selective agonists are longer-acting

Describe anaesthesia by injection into trigger points

used for diagnostic and therapeutic purposes in horses with recurrent pain

Describe buprenorphine

synthetic, partial opiate agonist;
30 times as potent as morphine;
produces dose-related analgesia;
exhibits many of the same actions as opiate agonists

Describe butorphanol

synthetic partial opiate agonist;
related structurally to morphine but exhibits pharmacologic actions similar to other partial agonists;
more potent than morphine, pentazocine, meperidine;
antitussive

Describe codeine

naturally occurring alkaloid with similar structure to morphine;
antitussive drug;
weak analgesic for mild pain;
rarely used in veterinary medicine

Describe COX-1

expressed in virtually all tissues;
catalyses the formation of constitutive prostaglandins, which mediate a variety of normal physiologic effects

Describe COX-2

activated in damaged and inflamed tissues;
catalyses formation of inducible prostaglandin;
involved in thermoregulation and pain response to injury

Describe epidural anaesthesia

injected into epidural space, blocking spinal roots;
surgery to abdomen, pelvis or extremities, mainly when general anaesthesia cannot be used;
slower onset compared to spinal anaesthesia

Describe ethyl biscoumacetate

used for prophylaxis and treatment of thrombosis and embolism

Describe fentanyl

synthetic opioid;
very potent opiate agonist (IV, transdermal);
transdermal patches used in dogs and cats;
used for adjunctive control of postoperative care;
parenteral solution contains droperidol (butryphenon[sedative]) induces considerable neuroleptanalgesia

Describe highly soluble sulfonamides

rapidly excreted mostly in unchanged form;
urinary tract infections

Describe how eyeball position can be used to test depth of anaesthesia

surgical anaesthesia (halothane, isoflurane): eyeball is rotated medially and ventrally;
early and late anaesthesia: eyeball is centrally placed

Describe hydromorphone

morphine derivative with similar duration of effect;
produces less emetic effect than morphine, but emesis and nausea occur frequently

Describe infiltration anaesthesia

direct injection into tissues to reach nerve branches and terminals;
used in minor surgery

Describe intermediate-acting sulfonamides

plasma levels are obtained in 12-24 hours

Describe intravenous regional anaesthesia

drug is injected intravenously, distal to a pressure cuff to arrest blood flow;
remains effective until the circulation is restored;
used for surgery, dentistry, analgesia

Describe location, formation, and structure of heparins

obtained from bovine liver and lung tissue, or porcine intestinal mucosa;
naturally formed in mast cells, basophils, and vascular epithelium;
heterogenous mixture of sulphated mucopolysaccharides

Describe long-acting sulfonamides

50μg/ml plasma levels obtained 24 hours after doing (Borgal, Trimetox)

Describe oxymorphone

morphine derivative with 10 times the potency;
produces less emesis, nausea, and sedation than morphine and hydromorphone on cats and dogs;
causes less histamine release in dogs

Describe pentazocine

similar pharmacologic effects as butorphanol;
effective for mild to moderate pain with 1-3 hour effect;
less sedation compared to other opioids;
can cause excitement and tremors at high doses

Describe plane 1 of anaesthesia

miosis, nystagmus, eyes become fixed centrally (cats and dogs),
skin and pedal reflexes lost

Describe plane 2 of anaesthesia

loss of palpebral and laryngeal reflexes;
respiration is regular

Describe plane 3 of anaesthesia

respiration is depressed;
cardiac contractility and blood pressure is reduced;
corneal reflex is lost

Describe plane of anaesthesia

overdose;
paralysis of the intercostal muscles and shallow abdominal respiration;
pupils very dilated;
pupillary reflex is lost

Describe poorly soluble sulfonamides

management of ulcerative colitis in dogs (sulfasalazine);
prevention and treatment of caecal and intestinal coccidiosis (sulfaquinoxaline, sulfaclozine);
intestinal infection

Describe remifentanil

undergoes non-hepatic metabolism (muscle and intestinal) resulting in short half-life (30 mins) and rapid clearance in dogs

Describe salicylic acid and sulfur as keratoplastics and keratolytics

keratoplastics at lower concentrations (

Describe short-acting sulfonamides

blood concentration remains above 50μg/ml for less than 12 hours after 1 dose (Norodine gran.)

Describe sodium warfarin

most commonly used vitamin K antagonist;
indicated for blood thinning as prevention of venous thrombosis and thromboembolism of aorta;
higher doses are toxic and cause haemorrhagic diathesis

Describe spinal anaesthesia

drug is injected into the subarachnoid space to act on spinal roots and spinal cord;
surgery to abdomen, pelvis or extremities, mainly when general anaesthesia cannot be used

Describe streptokinase

product of some strains of haemolytic streptococci of group C;
catalyses conversion of plasminogen to plasmin, which prevents the formation of blood clots or dissolves already formed clots

Describe the closed method of administration of general inhalation anaesthetics

use of anaesthesia apparatus and insertion of endotracheal tube;
depending on instrumentation, it has 2 modifications: 1-way and 2-way
advantage: low consumption of anaesthetic

Describe the corneal reflex

obtained by gentle palpation of the lateral aspect of the cornea causing the closure of the eyelids;
disappears in plane 2 of stage 3
(not always reliable in dog, particularly if eyeball is rotated)

Describe the disk diffusion method (antibiogram)

qualitative method;
antibiotic disks put on bacterial culture;
measurement of inhibition zone;
compare to interpretive criteria (disk producers)

Describe the E-test

quantitative method;
strips with concentration gradient;
MIC is determined as the intersection of the growth inhibition zone and calibrated test strip;
based on interpretive data established by manufacturer;
strain sensitive, resistant, intermediate

Describe the laryngeal/swallowing reflex

stimulated by attempting to pass an endotracheal tube;
disappears in plane 2 of stage 3

Describe the open method of administration of general inhalation anaesthetics

substance is dripped onto gauze in a mask;
anaesthetic acts slowly;
manifestations of excitation are more intense;
applicable to small animals

Describe the palpebral reflex

simulated by tapping the skin in the inner corner of the eye or by running a finger along the eyelashes;
reflex disappears in plane 2 of stage 3 in small animals

Describe the pedal reflex

obtained by adding firm pressure to the interdigital skin in dogs and cats, squeezing claws together in cattle and swine, and firm pressure on the pastern of horses;
reflex disappears in early stage 3, plane 1 and indicates deep anaesthesia

Describe the pharmacokinetics of sulfonamides

binds to plasma albumin, therefore high doses are required to penetrate target tissues;
elimination in urine, perspiration, teats, bile, milk

Describe the principle of dilution methods for testing of effectiveness of antibiotics

liquid medium with different concentrations of antimicrobial agent added to each tube/well;
after addition of inoculum and incubation the effectiveness of drug is evaluated according to the growth of microorganisms;
turbidity means strain is resistant

Describe the pupillary responses

pupil dilated in early excitement stage 2;
becomes progressively constricted in stage 3;
dilates again with entry into stage 4
(heavily influenced by pre-medication, species variations exist)

Describe the semi-closed method of administration of general inhalation anaesthetics

substance is collected in a special bag where is is reused effectively for re-action

Describe the skin reflex and muscle relaxation

(jaw tone)
decreases from maximum in stage 2 to stage 3;
muscles relaxed and skin reflex is lost in plane 1 of stage 3

Describe the use of etomidate

ultra-short acting hypnotic sedative with GABA-like effects

Describe the use of ketamine

rapid acting general anaesthetic with analgesic activity,
slow onset

Describe the use of propofol

onset of action is rapid,
induction is smooth,
duration of action short (2-10 minutes),
possible to use as a continuous infusion

Describe the use of tiletamine-zolazepam

nonnarcotic, nonbarbiturate injectable anaesthetic

Describe topical anaesthesia

applicated into eye, mucous membranes, or skin;
superficial loss of pain sensation after direct application

Describe topical sulfonamides

ophthalmic infections (sulfacetamide);
burn wounds (sulfathiazole, silver sulfadiazine, mafenide)

How are aminoglycosides divided?

1, 2, 3, 4 generations

How are antibiotics classified according to chemical structure?

β-lactams (penicillins, cefalosporins), tetracyclines, amfenicols, polypeptides and glycopeptides, aminoglycosides, macrolids, lincosamides, ansamycines, diterpens, antibiotics with different structure

How are antibiotics classified according to effect on microorganisms?

bacteriostatic, bactericidal

How are antibiotics classified according to mechanism of action?

cell wall synthesis inhibitors;
permeability of membrane;
protein synthesis inhibitors;
nucleic acid synthesis inhibitors

How are antibiotics classified according to spectrum of action?

narrow spectrum, broad spectrum, slightly broad spectrum

How are anticoccidial drugs used?

therapeutic, prophylactic

How are astringents used?

directly at the site of bleeding to control bleeding by constricting blood vessels and tissue to help slow and stop blood flow

How are cefalosporins divided?

1, 2, 3, 4 generations

How are lyophilised concentrates used?

applied to the skin (or a particular area) to help control capillary bleeding; normally absorbed by the body

How are macrolides divided?

1,2 generations

How are parasite infestations prevented?

employing complex prevention (healthy animals and surroundings);
improvement of physiological state of animal and host's resistance;
sanitation of pastureland;
preventative and therapeutic application of active substances

How are penicillins divided?

narrow spectrum, broader spectrum, β-lactamase resistant

How are quinolones and fluoroquinolones classified according to generations?

1st generation: quinolones
2nd-4th generations: fluroquinolones

How are sedatives administered?

IM, IV

How are sulfonamides classified according to duration?

short-acting, intermediate-acting, long-acting

How are sulfonamides classified according to solubility/use?

highly soluble, poorly soluble, topical

How are tetracyclines divided?

1, 2, 3 generations

How can dimeticon and simeticon be administered?

stomach tube or drench (diluted with water), or injected directly into the rumen

How can general anaesthesia be induced?

single drug or combination (hypnotics, sedatives, paralytics, analgesics)

How can myoclonus and excitement during induction or recovery of etomidate be prevented?

adequate pre-induction sedation with a tranquiliser or opioid drug

How do anticoagulants work?

block either synthesis of clotting factor VII (prothrombin) or the formation of fibrinogen

How do calcium chelators work?

chelate calcium that catalyses conversion of prothrombin to thrombin (with coagulation factors)

How do enzymes work as anticoagulants?

dissolve blood clots;
inactivate fibrinogen and fibrin

How do glucocorticoid drugs work?

(suppress virtually every component of the inflammatory process)
inhibit PLA2;
decrease synthesis of interleukins and other proinflammatory cytokines;
suppress cell-mediated immunity;
reduce complement synthesis;
decrease production and activity of leukocytes

How do NSAIDs work?

inhibit the activity of cyclooxygenase-1 and cyclooxygenase-2 that catalyse conversion of arachidonic acid to prostaglandins, thromboxanes, prostacyclins (mediators of inflammation)

How do sympathotropic agents work?

bind to adrenergic receptors

How do the subsystems of the autonomic nervous system work?

one activates physiological response and the other inhibits it

How do vitamin K antagonists work?

interfere with vitamin K dependent clotting factors (II, VII, IX, X) in hepatic synthesis of vitamin K

How does acetaminophen compare to aspirin?

weaker anti-inflammatory effects; similar analgesic and antipyretic effects

How does intensity of pulmonary ventilation affect the resorption of anaesthetics?

respiratory diseases decrease the resorption

How does meloxicam work?

potent inhibitor of prostaglandin synthesis

How does propofol cause direct myocardial depression?

decrease in Ca2+ and myofilament sensitivity to Ca2+

how does Tepoxalin work?

dual inhibitor of both COX-1 and COX-2, and 5-lipoxygenase (5-LOX)

How does the solubility of anaesthetics affect the resorption?

anaesthetic with low solubility in blood diffused from the lungs into arterial blood more quickly and there is only a relatively small number of molecules for achieving the increase in partial pressure of arterial tension

How is etomidate metabolised?

rapid hepatic hydrolysis (does not accumulate)

How is propofol metabolised?

glucuronide synthase in liver

How is thiopental metabolised?

slowly by hepatic microsomal system

How long after administration do dimeticon and simeticon act after oral administration?

5-15 minutes

How many planes are there in stage 3 of anaesthesia?

4

How should glucocorticoids be used?

in conjunction with therapies that target the underlying cause

In which animals is kaolin less effective?

young animals

In which animals is kaolin more effective?

older animals

In which animals is propofol used and for what?

cats and dogs,
short procedures or prior to inhalant anaesthesia

Neuroleptanaesthesia

general anaesthesia induced by the intravenous administration of neuroleptic drugs in combination with inhalation of a weak anaesthetic

Neuroleptanaglgesia

state of sedation and pain control induced for medical procedure by a combination of opioid analgesics and neuroleptics

What active substance is used to treat cryptosporidiosis?

paramomycin

What active substance is used to treat leishmania spp. infections?

pentamidine