Case 8 Flashcards
What are the two types antibiotics?
- Bacteriostatic
- Inhibits bacterial growth
- Allowing the natural immune response to eliminate the organism - Bactericidal
- Kills microorganism
- Most effective when cells are actively dividing, thus preventing cell division
What’s DAME?
The reasons for why people have falls. D = drugs A = ageing M = medical conditions E = environmental causes
How do drugs increase the risk of falls?
- ageing related changes - more accumulation
- polypharmacy - more drug interactions
- sedatives
- anti-hypertensives
- steroids - more likely to fracture and probably weakens muscles
- alcohol
Why do medical conditions increase the risk of falls?
- hypertension - damage to baroreceptors
- osteoporosis
- kyphosis
- pain
What’s pharmacokinetics and pharmacodynamics?
What your body does to the drug and what the drug does to your body?
What does pharmacokinetics involve?
- absorption
- distribution
(drug-cell interaction) - metabolism
- excretion
What changes are there with drug absorption as you age?
- Some slowing of gastric emptying / motility
- Some reduction in gastric acid secretion
- Reduced total surface area and reduced splanchnic (relating to the viscera or internal organs, especially those of the abdomen) blood flow
- Potential decrease in absorption of drugs (small change)
What changes are there with drug distribution as you age?
- Decrease in muscle mass and total body water, but increase in body fat
- Lipid-soluble drugs can accumulate in fat and brain tissue, e.g. benzodiazepines (for anxiety etc.)
- Water-soluble drugs will concentrate in plasma e.g. aminoglycosides, digoxin (so may have to give lower doses of these in older people)
- Changes in protein binding to albumin (family of globular proteins)
- may affect free fraction (parameter in pharmacokinetics and receptor-ligand kinetics) of the drug available e.g. warfarin
- NB often body mass is reduced in older patients
- Much more significant change in distribution as you age than absorption
What changes are there with drug metabolism as you age?
- Reduced hepatic volume and blood flow (about 40% in very elderly)
- Reduced first pass metabolism (means more drug available to exert its effect so may reduce dosage of drugs in older patients)
- Increased bioavailability of drugs metabolised by the liver e.g. propranolol, verapamil
- Other factors can inhibit hepatic enzymes and further impair hepatic drug metabolism
- smoking, alcohol consumption, coexisting diseases and some drugs (e.g. erythromycin, amiodarone)
What changes are there with drug excretion as you age?
- Renal function reduces with age (dramatic decrease after 40yrs)
- Reduced clearance of drugs which are:
- excreted via filtration at the kidney, e.g. digoxin
- actively secreted by the renal tubules e.g. penicillin
- Also reduced by coexisting chronic conditions e.g. hypertension, diabetes, congestive cardiac failure and acute illness e.g. UTI and dehydration
- all common in elderly people
- Can result in drug and metabolite accumulation and toxicity
- May need dose-reduction for renally-cleared drugs
How does pharmacodynamics change with age?
- Increased sensitivity at receptor level to many drugs = increased pharmacological effect and risk of toxicity
- gastrotoxicity, neurotoxicity, nephrotoxicity (kidney), hepatotoxicity, vasodilation
- Increased susceptibility to side-effects/ADRs than younger patients
What’s NNT and NNH?
Numbers needed to treat – the average number of patients who need to be treated to prevent one additional bad outcome
Numbers needed to harm – how many patients on average need to be exposed to a risk-factor over a specific period to cause harm in one patient who would not otherwise have been harmed
What are the 5 essential steps to shared decision making?
- Seek your patient’s participation
- Help your patient explore and compare treatment options
- Assess your patient’s values and preferences
- Reach a decision with your patient
- Evaluate your patient’s decision
What is Prednisolone, what does it treat, how does it work and what is the drawback?
- Glucocorticoid
- Used to treat: autoimmune conditions, hypersensitivity and inflammation (e.g. temporal arteritis)
- It suppresses the immune system by restraining the clonal expansion of Th cells (decreasing transcription of the gene for IL-2), thus leaving the patient susceptible to infection
- Long-term use of this glucocorticoid can lead to osteoporosis
What is Bendroflumethiazide used to treat and how does it work?
- Reduced uptake of water (by blocking Na/K pumps that would allow uptake of sodium and potassium ions and hence water) in the ascending arm of Loop of Henle (from the renal filtrate into the blood)
- Used to treat hypertension and oedema (water retention)
- Reducing the amount of excess water reduced the work of the heart
What is co-codamol used for and what is it composed of?
- Compound analgesic (painkiller) consisting of a combination of codeine phosphate and paracetamol
- Co-codamol tablets are used for the relief of mild to moderate pain when paracetamol alone does not sufficiently relieve a patient’s symptoms
What does codeine act as, what’s it effective for, and how does it work?
- Acts as prodrug (a medication or compound that, after administration, is metabolised into a pharmacologically active drug) it is metabolised to morphine
- Effective only in mild pain
- It blocks transmission of pain signals sent by the nerves to the brain
What is paracetamol and what can go wrong if you overdose?
- Analgesia (pain relief)
- Acute overdoses of paracetamol can cause potentially fatal liver damage
- Active ingredient in many flu medications
What is diazepam used to treat and how does it work?
- Used to treat: anxiety, insomnia
- Diazepam increased the activity of GABA in the brain
- GABA is a neurotransmitter that acts as a natural ‘nerve-calming’ agent
- It helps keep the nerve activity in the brain in balance, and is involved in inducing sleepiness, reducing anxiety and relaxing muscles
What is sepsis, what does it result from, how does it spread and what can it lead to?
- Sepsis is a common life-threatening condition triggered by infection
- Results from the body’s natural acute inflammatory response to infection
- Acute inflammation spreads via the bloodstream and can lead rapidly to:
- widespread inflammation (‘systemic inflammation’) and swelling
- low blood pressure and low blood flow to organs
- multiple organ malfunction (e.g. heart, lung, kidney, brain etc)
- multi-organ failure
- death
What is the most common cause of sepsis?
Bacteria
What are the warning signs of sepsis?
- Fever
- Rapid or difficult breathing
- Elevated heart rate
- New disorientation, confusion or drowsiness
- Severe muscle or joint pains
- Passing no urine
- A sense of impending doom
- Skin rash, mottled or discoloured
- Poor feeding (in infants and children)
What’s the acronym for sepsis?
Slurred speech Extreme muscle pain Passing no urine Severe breathlessness I feel I might die Skin mottled or discoloured
How can we save lives and improve outcomes with sepsis?
- Early suspicion
- Early diagnosis
- Early infection treatment
- antimicrobial drugs (broad spectrum initially until informed by culture results later)
- source control involving surgical intervention
- Emergency and critical care (supportive treatments)
- maintain blood pressure/flow and tissue oxygenation (adequate fluid and oxygen)
- support organ function
- ICU admission occurs in over 50% of cases in the wealthy nations
- Prevent infection spread
What are the contraindications to HRT?
- Breast cancer – oestrogen usually feeds breast cancer
- Thromboembolic disease – oestrogen is thromboembolic
- Coronary heart disease
- Stroke
- Gall bladder disease
- Migraine
Combined HRT vs. oestrogen-only HRT - who can you give each to and why? and how do they affect your risk of breast cancer?
You can’t give just oestrogen to a woman with a uterus because the oestrogen causes the lining of the womb to thicken and this can lead to endometrial cancer
- combined HRT increases the risk of breast cancer
- oestrogen-only HRT decreases risk of breast cancer
What are the benefits of HRT?
Helps:
- Vasomotor symptoms
- Mood changes and insomnia
- Osteoporosis
- Urogenital symptoms
- Sexual dysfunction
What are the best recommendations for dose and route of HRT?
- Use lowest dose for the shortest required time in women with natural menopause
- Women with premature menopause will need higher dose
- Transdermal oestrogen is safer than oral HRT; latest data suggests no increase in thromboembolic risk with transdermal oestrogen only preparations
What are the different definitions of osteoporosis?
- Osteoporosis: ‘a disease characterised by low bone mass (decreased bone mineral density (BMD)) and micro-architectural degeneration of bone tissue, leading to enhanced bone fragility and increase in fracture risk’
- The loss of entire bone substance
- WHO definition: BMD < 2.5 standard deviations below a normal healthy age-matched control (T score and Z score)
- values between -1 and -2.5 = osteopenia (condition in which BMD is lower than normal – it’s considered by many doctors to be a precursor to osteoporosis)
- T score: patient’s BMD compared to young healthy control
- Z score: patient’s BMD compared to age-matched control
What does osteoporosis result from?
Osteoporosis results from increased bone breakdown by osteoclasts and decreased bone formation by osteoblasts leading to a loss of bone mass
What are the symptoms of osteoporosis?
- Usually presented as a clinically evident fracture
- Stooping position develops as a result of fractured bones in the spine
- It may also be presented as backache
What are the risk factors for osteoporosis?
- Oestrogen deficiency (at menopause)
- Vitamin D insufficiency (lack of calcitriol means lack of calcium absorption)
- Hypocalcaemia (diet or hypoparathyroidism)
- Increasing age
- Female
- Sedentary lifestyle
- Asian descent
- Family history
- Long term use of corticosteroid medications (prednisolone)
- Excessive alcohol consumption
What are the treatments for osteoporosis?
- Non-pharmacological: calcium and vitamin D supplements
- Pharmacological: bisphosphonates, HRT (oestrogen) and SERMs
When are bisphosphonates used to treat menopause and how do they work?
- Treating postmenopausal osteoporosis
- Some forms of this medication are used to treat glucocorticoid induced osteoporosis
- Bisphosphonates inhibit the digestion of bone by encouraging osteoclasts to undergo apoptosis, or cell death, thereby slowing bone loss
How do SERMs work to treat osteoporosis?
- SERMs work agonistically (a substance which initiates a physiological response when combined with a receptor) (osteoporosis) and antagonistically (a substance which interferes with or inhibits the physiological action of another) (cancer)
- In bones, they bind to oestrogen receptors and activate them, thus mimicking the action of oestrogen
