PRESCRIBING ESSENTIALS Flashcards
PERCENTAGE CONCENTRATIONS
what does 1% w/w mean?
1g in 100g
example = hydrocortisone 0.5% w/w
- 0.5g hydrocortisone in 100g cream
PERCENTAGE CONCENTRATIONS
what does 1% w/v mean?
1g in 100ml
example = NaCl 0.9% w/v
- 0.9g NaCl in 100ml of infusion
PERCENTAGE CONCENTRATIONS
what does 1% v/v mean?
1ml in 100ml
example
- 70% v/v = 70ml of drug in 100ml solution
PERCENTAGE CONCENTRATIONS
what equation can help to work out concentrations?
concentration = mass / volume
CONVERSION FACTORS
how do you change between different weights?
METRIC UNITS
which units can be abbreviated and which measurements should be written out in full?
CAN BE ABBREVIATED
- kilogram (kg)
- grams (g)
- milligrams (mg)
CANNOT BE ABBREVIATED
- micrograms
- nanograms
- units
RATIOS
what does a 1:1000 ratio mean?
1g in 1000ml or 1mg per ml
RATIOS
what does 1:200,000
1g in 200,000ml or 5 micrograms per ml
WEIGHT CONVERSION
what are the basic weight conversions?
- 1 stone = 14 lbs
- 1lb = 450g
- 1 stone = 6.35kg
HEIGHT CONVERSION
what are the basic height conversions?
1 foot = 12 inches
1 inch = 25.4mm
1 foot = 304.8mm
PAEDIATRIC AGE RANGES
what is classed as neonate?
up to 1 month
PAEDIATRIC AGE RANGES
what is classified as an infant?
up to 1 year
OPIOID CONVERSION
what are the general rules?
- oral codeine is 10 x weaker than oral morphine
- SC or IV morphine is 2 x stronger than oral morphine
- SC or IV diamorphine is 3 x stronger than oral morphine
how do you calculate breakthrough pain dose?
1/6 of total daily dose
how do you wean off benzodiazepines?
switch to dose equivalent of diazepam and carefully reduce the dose to zero
