PRESCRIBING ESSENTIALS Flashcards
(18 cards)
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
CORTICOSTEROID CONVERSION
what are the general conversions?
5mg prednisolone is equilavent to:
- betamethasone 750 micrograms
- dexamethasone 750 micrograms
- hydrocortisone 20mg
- methylprednisolone 4mg
DILUTION
