Pharmacology Flashcards
What is a drug? Give some examples
-A substance which alters the chemical and biological processes occurring in the body
-e.g medicines, caffieine, alcohol, nicotine, cosmetics
What is pharmacology?
the study of how drugs affect tissue function
What is meant by the term indication?
the condition or illness for which a particular drug can be prescribed
What is meant by the term caution?
-when a drug is not recommended for use in patients with particular conditions/ comorbidities
-can be used to assess risk for pregnancy, kidney or liver disease
What is meant by the term contraindication?
-far more restrictive than a caution
-the drug should be avoided in a patient with a condition which is contraindicated
-e.g aspirin not given to children and teens due to risk of Reye’s syndrome
What is pharmacodynamics?
what the drug does to the body
What is pharmacokinetics?
what the body does to the drug
What are the 2 classifications of drugs?
- therapeutic basis e.g analgesics
- pharmacological basis e.g opioid
What is an analgesic drug?
-a drug that relives pain
-non opioids
-opioids
What is an antihypertensive drug?
-used to reduce blood pressure
-thiazide diuretics
-ace inhibitors
What is topical drug administration?
Applied to the site where the drug will act
What is enteral drug administration?
Taken orally
What is parenteral drug administration?
Introduced directly into the body
Why is the lock and key hypothesis important for dugs?
In order for a drug to be therapeutically useful it must act selectively on particular cells and tissues, showing a high degree of binding-site specificity
What happens when a drug interacts with their target?
-they interact to initiate a biological change or physiological response often mimicking or blocking chemical signals found within the body e.g hormones or neurotransmitters
What are the 4 different kinds of protein drug targets?
- enzymes
- carrier/ transport
- ion channels
- receptors
What are the 2 drug-target interactions?
-Agonist= if a drug mimics the natural chemical signal it will produce the same or an enhanced effect as the natural chemical signal
-antagonist= if a drug blocks the natural chemical signal it will prevent the effect of the natural chemical signal
What does a dose-response curve illustrate?
The relationship between the amount of a drug administered and the degree of biological response it produces
What are the 6 determinants of drug action?
- weight
- genetics
- other drugs
- nutrition
- illness
- age
What are older people more vulnerable to when using drugs?
-drug interactions
-side effects
-adverse drug reaction
What is the impact of genetics on drugs?
-our genes determine how our bodies handle drugs, often related to how drugs are metabolised
What are the 4 main stages of pharmacokinetics?
- absorption
- distribution
- metabolism
- excretion
What is absorption and what factors affect this?
-the movement of drug from its site of administration to the systemic circulation
-rate of gastric emptying
-disease
-transit through gut
-blood flow
-age
what is bioavailability?
the proportion of administered drug which reaches the circulation is classes as bioavailable
What factors affect distribution?
-blood brain barrier
-body volume (body fat can influence how long drugs remain in the body)
-fat or water soluble
-rate of blood flow
-blood protein binding
What is metabolism?
-When drugs are chemically changed from one chemical to another
-happens mostly in the liver
-can create toxic metabolites (e.g paracetamol)
how is the liver involved in metabolism?
-liver contains a family of enzymes called cytochrome P450 responsible for metabolism of many drugs
-also stores chemicals which can be added to drugs
-enzyme breakdown and conjugation help to make drugs easier to excrete
What factors affect metabolism?
-age
-liver disease
-genetics
-gender
-nature of the drug
-diet
-presence of other drugs
-enzyme inhibition
-enzyme induction
Where does excretion take place and what are drugs excreted into?
-mostly occurs in the kidney
-some drugs are excreted via bile into faeces some via the lungs and via sweat
What factors affect excretion?
-altered renal blood flow
-age
-pH of urine
-concentration of the drug in plasma
-molecular weight of the drug
What is toxicity as an adverse drug effect?
-where the primary effect of the drug is greater than the therapeutic effect and becomes harmful e.g insulin
What is an allergic reaction as an adverse drug effect?
-drugs cross react with either the same receptors in other body systems to different receptors to cause unwanted secondary effects
-stimulation of the immune system by drugs leading to allergic immune response e.g penicillin
What is the definition of half life and why is it important
-the time taken for the peak concentration of the drug in the plasma to be reduced by half
-provides information of dosing intervals and residual effects
