Pharmacology Flashcards
What is the goal of drug therapy treatment?
1.Prevent disease
2.Cure disease
3.Decrease mortality
4.Decrease illness
5.Descrease symptoms of illness
What is the rational drug prescribing?
1.Right drug
2.Right dose
3.Right frequency
4.Right duration
What is pharmacodynamics?
Effect of drug on body. Body responding to the drug. Site of action.
What is pharmcokinetics?
What body does to the drug. How quickly, slow, how does it stay and how does body absorb it
What is imporatant about precribing a medication that has a lot of different commercial names?
Always use a generic name
What are ACEI?
Angiotensis converting enzyme inhibitors
What are two different types of inhibitors?
Competetive and irreversible
Rank the quickness of receptors?
1.Ligand-dated ion channels – milisecond
2.G-protein-copled receptors – seconds morpheine (opiod receptors)
3.Kinase-linked receptors – hours
4.Nuclear receptors – hours to days – steroids (cortizone)
What is a therapeutic index?
It is a range of concentration of drug in plasma comparative to safe range. Essentially, drugs with a wide therapeutic index are safer because they hard to overdose on
What are the 3 most important parts of pharmacokinetics?
1.Absorption
2.Distribution
3.Elimination – metabolism and excretion
Why are pharmacokientics important?
Altered pharmakokinetics = harmful effect of drugs. E.g. CIclosporin + St. John’s Wort = transplant rejection. Also pharmakokinetics create a dosign regimen.
How do we determine the root of administration of drug?
1.Properties of the drug
2.Therapeutic objective – rapid response or chronic dosing
What is the advantages of sublingual, transdermal, rectal and injection pathway?
They bypass the first pass of the drug through the stomach, small intestine and liver
What is the pathway of gastrointestinal absorption?
1.Lumen
2.Enterocytes
3.Portal vein
4.Systemic circulation
How much water can we drink to empty a stomach?
200mL as it will make the stomach empty into the small intestine
Why do we use a enteric coating on aspirin?
Because aspirin may cause gastric bleeeding. On prescription, write swallow whole.
What are two different types of clearance?
1.Renal clearance – water solubles
2.Liver – lipid soluble drugs
What is metabolism?
Enymez convert one moleculue into a more water soluble one.
What are active metabolites?
Sometimes drugs are broken down into more active forms, thus if you give a high dose of a drug you more likely to overdose on an active metabolite of that drug.
How many half lives does it take to reach steady state?
5 half lives
What are some of aspect that effect variability?
1.Disease – kidney disease (lover dose), liver disease (no paracetamol)
2.Age – children (hihg clearance) Elderly (lover excretion, polypharmacy, Start Low & Go up slow & don’t stay low)
3.Pragnancy – all drugs no, contact GP to prescribe especially first trimeste, no ibuprofen, floconazole and oral isotretinoin – reduced GI motility
4.Genetic
5.Smoking
6.Food – grapefruit juice Drug-drug interaction
What are different type of drug-drug interaction (pharmakokynetic)?
Drug induction – Drug A induced Drug B increasing the sites of binding
Enzyme inhibition – Drug A blocks metabolism of Drug B resulting in accumulation of Drug B (miconazole)
Changes in renal clearance – Ace inhibitors, Nsaids and Diuretics (triple whammy)
What are different type of drug-drug interaction (pharmacodynamic)?
Potentiation – Drug A and Drg B effect the same target
Same mechanism – Drug A and Drug B taerget different receptors but have the same mechanism (CNS depressants + alchohol)
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What do adverse drug reactions do not include?
Overdose or error in dosing, those are adverse drug events.
What are major types adver drug responses?
Type A – augmented or increase effect - usually okay
Type B – Bizarre and unpredictable – high risk of death
What is the aims of drug regulation?
Protect public from:
1.Unsafe
2.Ineffective
3.Poor quality drugs
What are two major scedules for australia?
Aust L – no therapeutic claim
Aust R – have a therapetuic claim
How is saliva produced?
Trough parasympathetic (cholinergic)(watery) mechanisms and Sympathetic (adrenoceptors)(mucin and thick)
What neurotransmitter is used for cholinergic receptros?
Acetylcholine. Store in cells in vesicles and can be released in the systemic circulation (synaptic cleft) by calcium channels. There is 3 such receptors called muscarinic M1, M2, M3 (M3 is one is for glands).
What drugs are use as cholinergic agonists?
1.Direct acting – bind to activate muscarinic receptors – nicotine, lobeline and muscarine (aka magic mucshroom compound)
2.Indirect acting – inducing acetylcholinesterase (breakdown of acetycholine)
Blocking clholinergic antagonists result in:
Red as a beet
Blind as a bat
Dry as a bone
Full as a flask
Stuffed as a pepper
Mad as a hatter
Which drugs are used as cholinergic agonists (specific)?
1.Drugs for Urinary Incontienence
2.Parkinson’s disease
3.Gut motility disorders
4.Motion isckness
5.Pre-anaesthetics
6.Astham: inhalers
7.Antidepressants: Tricyclic antidepressant (not logner used much for depression but used for pain), serotonin selective reuptake inhibitors - important
8.Antipsychotics: Olanzapine, droperidol NOT CLOZAPINE that one cause hypersalivation - important
9.Antihistamines: sedating group is more common - improtant
10.Anxioklytic: anxiety drug
11.Antihypertensive
12.Benign prostatis hyper plasia
13.Appetite suppressants
14.Cytotoxic agents: radiotherapy
15.Diuretics
16Opiods
How can we help with xerostomia?
Efficacy in unproven:
- Saliva substitutes – Aqueae
- Salivary peroxidase
- Mouth washes
4.M3 receptor agonists
5.Check prescriptions and maybe stop taking the over counter medications
6.Sip water
- Ice blocks
8.Spray bottle
- Suagrless lollies or sugar-free gum
- Limit caffein & alchohol
- Adhere to preventative dental program
What is a prescription?
It is a legal document, a communication tool between you and pharmacist for preparing & dispensing a medication for your patient.
What are prescribing requirements?
Only for dental treatment of a patient under your care. Only for the person named on prescription. Cannot prescribe to yourself (only benzodiazapines and opioids). Please use ScriptCheck SA to reduce the number of drug dependent users.
What should be included on a prescriptions script?
Remember ePrescriptions are preferred
- Patient’s name, address and DOB
- Name & address of practitioner, phone number, qualifications, AHPRA reg
- Drug name – GENERIC
- Drug form – e.g. tablets
- Drug strength- e.g 15 mg
- Drug quantity in pills (word, symbol e.g Ten,10)
- Dose & frequency of administration
- Duration of days
- Instruction clearly
- Write (For dental treatment only)
- A line to signify no other prescriptions
- Signature of prescriber
- Date of prescription
- Signature
- PBS number for prescribers
What is important to know about all dentist prescribe drugs?
No repeats are available
What is released during the brekadown of cellular wall?
Prostoglandins – long chains of fatty acids which cause vasodilation, swelling and pain. Additionally, bradykinin is released which causes intense pain.
What do non-steroidal anti-inflammatory drugs target?
They block the work of COX1 and COX2 enzymes which prevents the creation of prostoglandins
What is important to remember about the cyclooxygenase enzymes?
COX enzymes are present throughout the body. COX1 is abundant and it maints our function. COX2 is in very low amount and lead to inflammation & pain because it is inducible. By inhibiting COX2, we can lower inflammation.
What is important to understand about ibuprofen?
It is an reversible drug. It is a non-selective COX 1 & 2 inhibitor. But is an effective analgesics in presence of inflammation. It reduce the production of psotoglandisnas and make receptors less sensative to bradykinin.
Do NSAIDS have adverse effects?
1.Gastrointestinal ulcers
2.Reduce platelet aggregation
3.Respiratory problems: increase asthma attack
4.Kidney: renal failure and water retention leading to heart failure and hypertension
5.Cardiovascular – uncommon BUT BAD
6.Neurological – headaches
7.Hematological – rare
8.Hepatic – rare
When should you not prescribe NSAID?
1.Kidney impairment
2.Heart failure or arterial fibrilation
3.Active GI ulcer
4.Bleeding disorder and their drugs
5.Corticosteroid or anticoagulation use
6.Multiple risk factors for increase NSAID toxicity
7.If unsure contact GP
What questions should you ask particularly an elderly before prescribing an NSAID?
- Have you experience recent changes in your bowel habits, such as black or tarry stools?
- Any episodes or recent nausea, vomiting or abdominal pain?
- Have you noticed any changes in your urine output or color?
- have you experienced any shortness of breath, chest pain or swelling?
- Do you have a care giver or support group that may aid you or remind you about taking the medication?
- Do you take any over the counter medications recently that are beyond the once in your medical history?
- Do you take a deuretic or an ACE inhibitor?
What can we use an NSAID for?
Mild-moderate acute inflammatory pain. Usually 1200mg/day, 400 mg per 6 hours for 2-3 days if pain persists you should go to GP.
What is an opiod?
It refers to a generic sense to all drug with morphine-like actions. Please use this term
What is a good combination of medication to ue post 3rd molar extractions?
150mg of ibuprofen + 500mg of panadol x6 times a day.
What can be used in temporary relief of painful inflmmatory oral mucosal conditions like mucositis?
Benzydamine, an NSAID in a spray form.
What receptor does the opioid bind to?
It is the mu receptor pre- and postsynaptically causing the reduction in pain transmission pain impulses. Resulting in lower feeling of pain.
What are opioids are used for in dental?
1.Acute pain
2.Persistent cancer pain
What is the most important side effect of opioids?
Respiratory depression. Additionally, sedation, nausea, euphoria, constipation and dry mouth.
Why are opiods good?
Great analgesia. Relief of anxiety. Reliable and rapid onset.
Why are opiods bad?
Side effects, dependence, tolerance
What can dentist prescribe?
- Morphine – not recommended in dentistry as it is not for acute pain
- Codeine – less potent for gram then morphine about 1/10 - not good for dental pain
- Oxycodone - not that good
- Tramadol – not a drug of dependence – a lot of tummy aches - go with this first!
What can you use to reverse the effects of an opioid?
Naloxone
What is conscious sedation?
It is a drug-induced depression of consciousness during which patient are able to respond purposefully to verbal command or light tractile stimulation. All conscious sedation techniques should provide a margin of safety that is wide enough to render loss of consciousness unlikely
What is deep sedation?
When consciousness is lost, airway is lost and only pain can be responded to. This is more dangerous.