Pharmacology

Question 1

Functions of Sympathetic System

Answer 1

• Increased heart rate and force of contraction
• Raise blood pressure
• Dilate pupil
• Dilate bronchi
• Stimulate conversion of liver glycogen into glucose
• Shunt blood away from skin to viscera
• Inhibit peristalsis in GI tract
• Inhibit contraction of bladder and rectum

Question 2

A1 Receptor Locations

Answer 2

BIGBHSPM

Blood vessels, iris, GI tract, hepatocytes, sweat glands, piloerector muscles, bladder sphincter, amle and femal reproductive tract

Question 3

A1 Receptor Stimulation Causes

Answer 3

Vasoconstriction and increased blood pressure, mydriasis (pupil dilation), contraction of gut sphincters and reduced gut motility, urinary retention by contraction of sphincter, increased bile secretion and increased glycogenolysis, uterin contractions and ejaculation, sweating, piloerection

Question 4

A2 Receptor Location

Answer 4

Presynaptis adrenergic terminals for neagtive feedback control, postsynaptic of pancreas and some vascular beds

Question 5

Location of B1 Receptors

Answer 5

MARG

Myocardium, adipocytes, GI tract, renal arterioles

Question 6

B1 Receptor Stimulation Causes

Answer 6

Chronotropic and ionotropic effects, increased lipolysis giving increased blood lipids, reduced GL motility, release renin-angiotensin II to cause vasoconstriction

Question 7

B2 Receptor Locations

Answer 7

BSBMUH

Bronchial smooth muscles, skeletal muscle, blood vessels in brain, heart, kidneys, skeletal muscle, mast cells, uterus and hepatocytes

Question 8

B2 Receptor Stimulation Causes

Answer 8

Bronchodilation, increased skeletal muscle excitability, vasodilation of tissues, relaxation of pregnant uterus and increased contraction on non-pregnant uterus, decreased bile secretion, increased glycogenolysis, stabilise mast cell membranes

Question 9

Functions of Parasympathetic System

Answer 9

• Slowing heart rate
• Lowering of blood pressure
• Constriction of pupils
• Increased blood flow to skin and viscera
• Peristalsis of GI tract

Question 10

Muscarinic Receptor Types and Locations

Answer 10

M1 - cortex and hippocampus

M2 - heart

M3 - endocrine glands and GIT

M4 - neostriatum

M5 - substantia nigra

Question 11

Nicotinic Receptor Locations

Answer 11

Centrally, ganglia, neuromuscular junctions of skeletal muscle

Question 12

Factors Affecting Topical Route

Answer 12

Molceular weight, lipophilicity, uncharged, epidermis actively metabolizes drugs, effects of vehicle or formulation, regional differences or site of application.

Question 13

Advantages and Disadvantages of Enteral Route

Answer 13

Advantages include convenien, no need to be sterile, cheap, liquid/solid/suspension, safety margin, slow absorption due to food, slow release, local effects.

Disadvanatges include drugs degraded by gastric aciditiy, affected by food, metabolized yb liver firs pass effect, insoluble drugs, slow onset of action, inconvenient when vomitting, aggressive or unconcious.

May also be affected by diarrhea, gut inflammation, antibiotics and liver disease

Question 14

Advantages and Disadvantages of Parenteral Route

Answer 14

Advantages include more rapid and higher blood levels, no intestinal degradation, no first pass effect, liquid or solid (must be liquid for IV), dart guns

Disadvantages include drug must be sterile and pyogen free, sterile administration apparatus, multiple dosing, injured muscles.

IV particularly useful when drug is an irritant, titrate dose to effect, rapid response, inject large volumes.

Question 15

Advantages and Disadvantages of Intraperitoneal

Answer 15

Advantages include larger absorptive surface areas, better than IM/SC, crystalloid administration, anaesthetic drug administration in small rodents.

Disadvantages include may cause peritonitis, may restrict breathing, potential for discomfort, damage to organs from needles.

Question 16

Factors Affecting Pharmacokinetics

Answer 16

1. There is liver disease. Reduced liver function can result in reduced synthesis of protein – hypoproteinaemia – so there will be more free (un-bound) drug. This can lead to increased drug efficacy and/or increased toxicity.
2. There is starvation or catabolism (as occurs in many diseases). Again hypoproteinaemia may occur.
3. There is renal disease with increased glomerular filtration – i.e. the glomerular vasculature “leaks” protein into the tubules. Protein-bound drug may be lost from the circulation due to the loss of protein through the damaged glomerular endothelium. Normally, the glomerulus will not pass proteins (>MWt 20,000) into the urine.