Pharmacology 2 Flashcards
What is a drug?
- An external substance that acts on living tissue to produce a measurable change in the function of that tissue
- Very broad definition - use of drug is a very broad phrase
What are side effects of drugs?
- Effects you want and effects you don’t want (the drug just does what it does - it will always do the same)
- It is not really a side effect - it is just something that the drug will do, some are advantageous and some are not
What is the most commonly used drug in dentistry?
- LA
What is the function of local anaesthetic in dentistry?
- Prevent pain
What is the function of antimicrobials in dentistry?
- Treat and prevent infections
What is the function of anxiolytics?
- Reduces anxiety
What is the function of analgesics?
- Drug that provides pain relief (reduces postoperative pain)
Medical drug use may affect dental care. Why is this?
- Medication patients are on may affect what you can give to the patient
What can drugs do in respect to body communications?
- Can stimulate or interrupt normal body communications
What can drugs do in relation to non-host organisms?
- Can act on non-host organisms to aid body defences
- Antimicrobials slow down the action of the organisms so that the host can get on top of it and own body defences can do their job properly
- They work at a cellular level to continually disrupt and prevent the growth of microorganisms
What are the 2 ways in which chemical messages can be sent round the body?
- Hormones
- Neural messages
- Both can be stimulated or interrupted
What do hormone messages send round the body?
- General information to ALL tissues
What do neural messages send round the body?
- Targeted info for SPECIFIC tissues
Give 4 examples of common hormones in the body?
- Thyroid hormone
- Insulin
- Cortisol
- Sex hormones
What is cortisol?
The principal hormone secreted by the adrenal glands. It is a potent anti-inflammatory agent and is used for the palliative treatment of a number of conditions, including itching caused by dermatitis or insect bites, inflammation associated with arthritis or ulcerative colitis and diseases of the adrenal glands
What is the function of thyroid hormones?
- Balances body’s metabolism
- Too much = hyperthyroidism
- Too little = hypothyroidism
What are some of the effects if thyroid hormones are at the wrong concentrastion in the body?
- Cold intolerant
- Slow metabolism
- Hair loss
- Slow pulse and low blood pressure
What is the function of thyroxine tablet and where in the body does it act?
- Replaces the missing T3 & T4
- The dose is adjusted to correct the level gradually
- It acts directly in the tissues - has no direct effect on the thyroid gland
What is hypothyroidism?
- Abnormally low activity of the thyroid gland, resulting in retardation of growth and mental development in children and adults
What is hyperthyroidism and what are some common symptoms?
- Occurs when they thyroid makes too much T3, T4 or both
- Common symptoms include excessively high metabolic rate, rapid HR, elevated BP, sweating and low tolerance to heat, nervousness, bulging of the eyes and many more
A common sign of hyperthyroidism is bulging of the eyes, this is a sign of exophthalmos, what happens in the eye to cause this?
- There is swelling, fibrosis and scarring of the tissue behind the eye muscles surrounding the eye. This crowds the bony orbit where the eye sits, causing the eyes to bulge forward
Nerve control controls heart rate, what is the sympathetic and parasympathetic effect on the heart?
- Sympathetic - adrenergic stimulation
- Speeds up the heart via beta-receptors
parasympathetic - Cholinergic stimulation
- Slows the heart via cholinergic receptors
What is the name for the autonomic drug that is a beta agonist?
Epinephrine
What is the name for the autonomic drug that is a beta blocker?
Atenolol - prevents the normal hormone from stimulating by blocking the receptor
What is the name for the autonomic drug that is a cholinergic agonist?
- Pilocarpine
What is the name for the autonomic drug that is a cholinergic blocker?
Atropine - Takes away the slowing effect on the heart
- At rest the heart rate is kept artificially low due to the cholinergic system
What are the different ways in which drugs can interact with tissues? (3 points)
- Receptors
- Enzymes
- Ion channels
Drugs binding to receptors themselves is not enough, the receptor must be coupled to something. What 4 things can receptors be couples to?
- Ion channels
- G-proteins
- Enzymes
- Gene transcription
What is a partial agonist?
- Binds to the receptor and causes a bit of a change so you get some of the response but not all of the response
What are the 2 components to drug-receptor interactions?
- Drug-receptor interaction (affinity and occupancy)
- Drug indices response (efficacy)
What is meant by drug affinity?
- How avidly a drug binds to its receptor (how much attraction these is between a drug and a receptor)
What is meant by drug occupancy?
- The proportion of receptors occupied by a drug
What is meant by drug efficacy?
- How effective is the drug of choice in producing the change you want to see
Which law will a drug in the vicinity of a receptor obey?
- The law of mass action
What is an agonist?
- Binds to a receptor and causes an effect
- A substance which initiates a physiological response when combined with a recept or
Will increases the concentration of a partial agonist improve the efficacy?
it will for some but not for others
What is the name for a reversible antagonist and what reduces the effect of this?
- Competitive
- Antagonist effect reduced by increasing the concentration of the agonist
What is the name for an irreversible antagonist and what does it do?
- Non-competitive
- Binds and reduces the available receptors of the agonist to bind to
What are the 2 types of enzyme modification?
- Reversible and irreversible
What are examples of drugs that disrupt the cell ion balance by either electrical activity or ion influx?
- LA
- Anti-diabetic drugs
