GP Flashcards
Why does depression and anxiety matter in chronic disease and why is it challanging?
It matters because it is very common (more common in people with chronic disease), it is associated with non-compliance and poor outcomes.
It is challenging because there is lots of symptom overlap and high risk of polypharmacy
Define multimorbidity and polypharmacy
- Multimorbidity is 2+ conditions.
- Polypharmacy is being on 5-10+ drugs
What are the determinants of multimorbidity?
Social - Socioeconomic, psychosocial and behavioural determinants.
Biological - aging and inflammation
What is supportive self management? and how can you encourage it?
Supporting a patient to build skills, behavior’s and capacity to live well and manage their long term condition. Do via agenda setting, goal setting and action planning and goal follow up. Positive affirmations
What are the social determinants that can affect health?
Conditions people are born into, grow, live, work and age
What is a better alternative for BMI?
Edmonton Obesity Staging System (EOSS)
What is pharmacodynamics?
Pharmacokinetics
- What the drug does to the body,
- What the body does to the drug
How is bioavailability expressed and what is it effected by?
- Expressed as F, it is affected by drug factors, absorption of drug which can be affected by gastric pH or health of GI tract, first pass metabolism.
- Grapefruit juice may increase bioavailability
What is clearence?
The volume of plasma cleared of drug per unit time
What is half life?
Time required for serum plasma concentration to decrease by half. It is determined by the clearance and volume of distribution
How can age affect pharmacokinetics
With age there is a decrease in body water and an increase in body fat, so serum levels of water soluble drugs may increase (due to the decreased volume of distribution) and the half life of fat soluble drugs is increased.
Absorption remains relatively the same and the affects on first pass metabolism can vary
How can age affect the liver
Oxidative metabolism via CYP450 system decreases so there is decrease clearance of drugs
How can you accurately measure drug excretion by kidneys?
Cr Cl (crockroft and Gault)
How can age affect pharmacodynamics?
- Effects of alcohol, opiates, sedatives and theophylline are increased.
- Effects to beta blockers are decreased
What are some common drug interactions?
- Statins and clarithromycin,
- Verapamil and beta blockers,
- Warfarin and aspirin,
- Ace inhibitors increase the hypoglycaemic affect of sulfonylureas.
What is the prescribing cascade?
When you prescribe a drug to treat the side effects of another drug
What are the affects of renal disease on pharmacodynamics and pharmacokinetics
pharmacodynamics - Altered sensitivity to the drug and increased adverse effects.
Pharmacokinetics - Decreased elimination, decreased protein binding and decreased hepatic metabolism
Summary - Prolonged elimination so increase the dosing interval
Why is protein binding affected in renal disease?
- Renal failure leads to acid retention so acidic drugs become less bound to albumin and therefore the amount of free drug is increased
What drugs must be stoped in renal disease?
Metformin and NSAIDs. Caution with ACE inhibitors and reduce the dose of many others
What are the affects of hepatic impairment on pharmacokinetics and pharmacodynamics?
Pharmacokinetics - First pass metabolism is affected, activation of prodrugs is affected, decreased protein binding and decreased elimination.
Pharmacodynamics - altered sensitivity to drugs
Summary - Slower rate of enzyme metabolism (increased bioavailability and half life) so lower dose and increase dosing interval)
What are high extraction drugs?
Drugs which are metabolized at high rates by the liver. They can be affected by changes in blood flow. Liver disease may cause big peaks in these drugs
Eg, morphine, verapamil.
What are low extraction drugs?
Drugs which are metabolized by the liver at low rates, eg theophylline. Longer half life in liver disease
How can congestive cardiac failure affect drugs?
- \Reduce absorption, reduced hepatic metabolism, and reduced renal elimination
What is frailty?
Gradual loss of physiological reserve and higher risk of decompensating
What can impact immigrants access to healthcare?
- ## Residence, social networks, legal status, health literacy, discrimination, financial security,
