Pharmacy Flashcards
(27 cards)
Acidic drugs require an acidic environment to be absorbed, and basic drugs require a basic environment to be absorbed. True/False?
True
Give 3 examples of acidic drugs
Penicillin
Aspirin
Phenytoin
Give 3 examples of basic drugs
Diazepam
Morphine
Pethidine
What will the absorption of penicillin be like if you take a PPI at the same time?
PPI remove HCl from stomach, so less acidic environment, so penicillin won’t absorb as well
Which basic carrier protein binds acidic drugs?
Albumin
Which acidic carrier protein binds basic drugs?
Alpha-1 acid glycoprotein (A1AG)
In the elderly, which carrier protein is higher in abundance - albumin or A1AG?
A1AG (bind better to basic drugs)
Relative low albumin concn
Vd is a theoretical volume describing if all drug was absorbed into blood. The bigger the Vd, the more/less lipid soluble it is.
Vd is a theoretical volume describing if all drug was absorbed into plasma/blood. The bigger the Vd, the more lipid soluble it is.
What effect does a large Vd have on half-life of a drug?
Half-life of drug increases (big Vd means drug is sitting in adipose tissue)
Give the equation for calculating the therapeutic index of a drug
LD50/ED50
lethal dose50)/(effective dose50
List some drugs that have a narrow therapeutic index
Warfarin Theophylline Levothyroxine Digoxin Lithium Vancomycin Gentamicin
What is a common side effect in elderly people being on PPIs? What is an alternative?
Hypomagnesia, hypokalaemia, hyponatraemia
Ranitidine
What side effects of oral NSAIDs must you consider when prescribing to an elderly person? What is the alternative?
Gastritis and ulcers
Fluid retention
Reduce effect of diuretics and antihypertensives
Topical NSAIDs, paracetamol
What must you consider when assessing an elderly patient on vasodilating antihypertensives? What are examples of these.
Reduction in BP
ACEi, CaCB
Elderly people on broad-spectrum antibiotics have an increased risk of C.diff compared to the average person. True/ False? What are these antibiotics?
True
4 Cs: co-amoxiclav, cephalosporins, clindamycin, ciprofloxacin
What are some side effects of elderly patients on bendroflumethiazide?
Hypoperfusion Biochemical imbalance (hypokalaemia, hyponatraemia)
What type of drug has a high Vd and what type has a low Vd?
High = lipophillic (lots of drug in fat) Low = hydrophillic (lots in plasma)
What is the equation for t1/2?
0.693 x Vd/ Cl (r+h)
Why do you need to consider reducing the dose of drugs that work by 1st pass metabolism? Give an example.
Liver function is reduced in elderly people
Propranolol
What is the equation for creatinine clearance?
((140-age) x body weight (kg)/ serum Cr) x 1.23 for men/ 1.04 for woman
Why might creatinine be an ineffective marker in elderly people?
It is muscle mass dependant
What combination of drugs can impair psychomotor function?
Opiods
Benzodiazepines
What is an important side effect to consider for an elderly person on furosemide?
Incontinence
What are the most common side effects of medications seen in elderly people?
Cognition and consciousness problems
Bowel function especially constipation
Dizziness and balance problems i.e. postural hypotension and parkinsonism (risk of falls/immobility)
