pharmacology Flashcards
medicines act 1968
POM - prescription only medicines
P - pharmacy only medicines
GSL - general sales lists
what does ‘off label’ use mean
- the medicine being used in a way that is different to described in license
examples of off label uses
- using medicine in age group outside licensed range
- using medicine at higher dose than stated in license
- using medicine for a different illness to that stated in license
what does unlicensed use mean
- medicine has license in other countries but not UK
- medicine has license but made up of unlicensed formulation
- medicine has no license at all - used for treating rare illnesses
drugs act 2005
- aggravated supply of control drugs
- police powers in drug offences
- testing for presence of class A drugs
poisons act 1972
- non-medical poisons
- arsenic and strychnine
- little relevance to hospitals
prescription of medicine human use order 1997
- appropriate practitioners
- medicinal products that are prescription only
- medicinal products that emit radiation
- exemptions
contrast media
- used extensively in radiology to provide contrast between different structures
- dependent on doctors scope of practise and patients diagnosis
contrast media definition
- various agents used to facilitate distinction between structures on images as consequence on differences in contrast
two basic categories of contrast agents
- negative contrast agents
- positive contrast agents
radiolucent
- negative contrast agents
what are negative contrast agents used for
designed to make the intraluminal contents dark, especially on T2-weighted images
- produces denser image
qualities of negative contrast agents
- have low atomic number
- more radiation transmitted through gas than bone
- air alone can provide sufficient contrast
negative contrast media
- air
- sodium bicarbonate
- water
- carbon dioxide
what are positive contrast agents used for
shorten relaxation times and increase intraluminal signal on T1-weighted images
radiopaque
positive contrast agents
qualities of positive contrast agents
- high atomic numbers
- high absorption of x-rays
- contrast appears lighter
- can be introduced to tracts, cavities + physiological systems
why are elements with high atomic numbers used for positive contrast agents
- cause an increase in attenuation of x-rays
- eg barium and iodine
- radiopaque
non-ionic contrast
tri-iodinated substituted ring compound
- routine
- 1:80 000 risk
- severe reactions 0.04%
- very severe reactions 0.004%
water soluble iodine agents
- gastrograffin and urograffin
- relatively safe
- very small chance of a reaction
