option d - medicines and drugs Flashcards
effects of drugs and medicines on bodies
- alter physiological state
- alter incoming sensory sensations
- alters mood or emotions
medicine vs drugs
medicines alleviate symptoms by supplementing natural healing processes, drugs target enzymes to bring about change in biological functions
therapeutic level
the beneficial effect of a medicine
line of defense definition and example
mechanisms employed by the body to protect itself against foreign pathogens, such as the skin
placebo effect definition
beneficial effect produced by a treatment which cannot be attributed to the treatment, but to the patient’s belief in the treatment
types of injection
intravenous, subcutaneous intramuscular
methods of drug administration
oral, suppository/rectal, inhalation, skin patches
limitations to oral drugs
inability to swallow in unconscious, pediatric, and geriatric patients, and longer time to take effect
bioavailability definition
the fraction of an administrated dose that reaches the target part of the body
factors impacting bioavailability
solubility in water, solubility in lipids, functional groups
first-pass effect
when oral drugs reach the liver they are metabolised and their bioavailability reduced to 4x less than intravenous
advantage of water soluble drugs
can circulate in aqueous solutions in blood
advantages of lipid soluble drugs
can pass through membrane
functional group impact on bioavailability
ionised forms of carboxyls and amines are more soluble in aqueous solutions
therapeutic effect vs side effect
therapeutic is intended impact, side is unintended
examples of side effects
positive - aspirin prevents heart disease
benign - nausea
negative - organ damage and mutagenic properties
danger of tolerance
although tolerance can increase, lethal dose may not so patient may approach dose that can poison them
causes of tolerance
- more efficient metabolism of drugs
- drug receptors become less effective
dosing regime definition
a plan that outlines the dose, duration, timing, frequency of a drug
factors that can impact dosage of drug
- sex
- weight
therapeutic window definition
range of concentration of a drug in the bloodstream that is high enough to have beneficial effects but not high enough to trigger unnacceptable side effects
therapeutic index definitions
measure of a drug’s safety, high TI indicated large therapeutic window, calculated using LD50/ED50 in animals and TD50/ED50 in humans
role of receptors in drug action
cells have receptors on their membranes that a drug binds to to inhibit biological activities which interrupts the development of a disease, better fitting drugs have higher activity
bonds between drug and receptor
ionic, hudrogen, van der waals
supramolecular complex definition
complex formed by two molecules through non-covalent interactions, such as between a drug and receptor
stages of drug testing and development
- identify need and structure
- synthesis
- yield
- extraction
rational drug design definition
- compounds with biological activity identified
- combinational chemistry used to produce large numbers of drugs
- high through-put screening tests a large number of drugs on a large number of targets
- animal and human testing occurs
phases of human testing
I - small number of healthy volunteers to assess safety and dosage
II - larger number of patients for statistical testing of efficacy
III - very large number of patients, double blind experiments with 50% drug and 50% placebo
mild analgesics impact
intercept pain stimulus at the source, such as by interfering with the production of substances that cause pain, swelling, or fevers, such as prostoglandins
