Clinical Pharmacology Flashcards
What are drug categories in dentistry an what is their role?
Local anaesthetic - Prevent pain!
Antimicrobials -Treat and prevent infections
Anxiolytics - Reduce anxiety
Analgesics - Reduce postoperative pain
What are the types of host communication?
Hormone messages
- General information to ALL tissues
Neural messages
- Targeted information for SPECIFIC tissues
What are examples of hormone systems in the body?
Thyroid Hormones – T3 & T4
Insulin/glucagon
Cortisol/Aldosterone
Sex Hormones
What do thyroid hormones do?
balance body’s metabolism
How can hypothryroidism be treated?
Drugs can replace the missing active hormone - T3 & T4
Thyroxine dose adjusted to correct level gradually
Replacement medicine acts directly in the TISSUES, no direct effect on thyroid gland
How does the automomic nervous system communicate? (what types)
Sympathetic - Adrenaline
Parasympathetic - Acetylcholine
How does the sympathetic system speed up heart rate?
Sympathetic - adrenergic stimulation
Speeds up the heart via Beta-receptors (B1)
How does the parasympathetic system slow down heart rate?
Parasympathetic – cholinergic stimulation
Slows the heart via cholinergic receptors (M2)
What are examples of autonomic drugs?
Adrenaline (beta agonist)
Atenolol (beta blocker)
Pilocarpine (cholinergic agonist)
Atropine (cholinergic blocker)
What are the routes of administration?
Transdermal - drug applied to the skin for adsorption
Subcutaneous - drug injected into the tissues of the skin
Intramuscular - drug injected into muscle
Intravenous - drug injected into a vein
Transmucosal - drug applied to the mucosa for adsorption
What is a drug applied to the tissue where it acts called?
topical
What is a drug applied to the whole organism called?
systemic
What is the main purpose of aspirin and what side effect is also useful?
aspirin reduces pain (NSAIDS)
side effect - platelet inhibitor for heart attacks
What reaction is commonly seen in penicillan allergy?
mild maculopapular rash
What happens in anaphylaxis?
Swelling of tissues
narrowing of airways
leadings to circulatory failure
What are drug interactions?
One Drug interferes with the absorption, action or metabolism of another
What drugs have interactions commonly in dentistry?
warfarins and NSAIDs (aspirin)
protein bind
What is another example where warfarin interacts with another medication?
warfarin and erythromycin/ fluconazole/ carbamazepine
decreases drug metabolism of warfarin
What can acute toxic reactions lead to?
Bone marrow suppression
Hepatotoxicity & biliary stasis
Acute nephrotoxicity
What should be considering before prescirbing?
would a different treatment be a better option? (surgery, filling)
What can prescribing the wrong drug cause?
ADR - adverse drug reaction
ineffective
less effective
When is the prescription valid for?
six months from date issued
What is different for private prescriptions?
GDC number added instead of NHS list number
What are advantages of written instructions?
Stressed patient may not remember instructions
Language issues may prevent proper understanding
Multilingual options, large print options
Contact number for Patient if Issues arise with the medicine
Legal protection if post-treatment course questioned
What should advice to patients be?
Take drugs at correct time and finish the course
Unexpected reactions: STOP! and contact prescriber
Known side-effects should be discussed e.g. Metronidazole and alcohol
Keep medicines safe: especially from children
Where can dentists refer to regarding drugs?
BNF
SDCEP
What are the 4 modes of action?
Activation or blocking of Receptors
Activating or blocking Enzyme function
Opening or blocking Ion Channels
Facilitation or blocking Transport systems
What is the difference between antagonist and agonist and inverse agonist?
- Agonist: Increases activity above baseline.
- Inverse Agonist: Decreases (already present) activity below baseline.
- Antagonist: Blocks the effects of both agonists and inverse agonists, but has no effect on its own.
Why is the drug/receptor interaction not enough?
a cascade is required which happens due to the conformational changes in transmembrane proteins
What is the effect of the drug determined by?
Affinity – the tightness of the drug binding to the receptor
Occupancy – how much time the drug spends on the receptor
Efficacy – how effective the drug is at producing a response from the receptor
What is the drug at an equilibrium with?
with surrounding tissue fluid
it spends time in receptor and in fluid
What does a low affinity in turn cause?
low occupancy > low effect
What can a low affinity be combated by?
increasing the dose of the drug
however in some drugs even increasing the concentration will not acheive max efficacy (partial agonist)
Why is butyrylcholine (BCh) a partial agonist?
max effect will never be obtained despite the concentration
What law do drugs in vicinity of a receptor obey?
law of mass action
What is a non-linear relationship between occupancy and response?
an increase in occupancy may not have an effect on the response to the drugs, ie. at half occupancy reponse could be max