Pharmacy Flashcards
What is pharmacokinetics?
the study of what the body does to a drug (i.e. how the drug is handled)
What is pharmacodynamics?
the study of what a drug does to the body (i.e. how it works)
What is the ADME principle?
Absorption
Distribution
Metabolism
Excretion
What does the rate of absorption of drugs into systemic circulation depend on?
the route of administration
What are the different methods of absorption of drugs?
- Oral
- Buccal (via the cheek)
- Inhalation
- Rectal
- Topical
- intravenous/ Intramuscular/ Subcutaneous
What is topical absorption of drugs?
absorption through the skin
Why is rectal absorption of drugs efficient?
reduced 1st pass metabolism
Why is inhalation absorption of drugs efficient?
large surface area and high blood flow
Why is buccal absorption of drugs effective?
high blood flow, avoids 1st pass metabolism
Why is oral absorption of drugs efficient/inefficient?
- convenient
- efficient
- difference in pH
- subject to 1st pass metabolism
What is the 1st pass metabolism & bioavailability?
1st pass effect decreases the active drug’s concentration upon reaching systemic circulation or its site of action
(often associated with the liver)
What are important factors determining distribution?
- Protein binding
- Blood flow
- Membrane permeation
- Tissue solubility
What factors influence drug metabolism?
- Genetics
- Age
- Gender
- Liver Size & Function
- Circadian Rhythm
- Body Temperature
- Nutritional State
- Other medications (can increase/decrease metabolism)
What are common protein targets for drugs?
- Receptors
- Ion channels
- Carrier molecules
- Enzymes
What are examples of pro-drugs?
- Codeine
- Enalapril
- Dabigatran
- Gabapentin
What are pro-drugs?
inactive drugs given orally, which rely on conversion by enzymes into the active drug
Why do we need medicines management?
- Growing number of people living with a long-term condition (LTC)
- 25% of people over 60 report having 2 or more LTCs
- Estimated the >2.9 million people in the UK have multimorbidity (NICE 2015)
- Increase in polypharmacy (esp. elderly)
- Increased exposure to number of prescribers
- Medicines need to be optimised (managed) to improve safety, improve concordance, reduce waste & costs
- Often seen as ‘someone else’s job
What are the benefits of non-medical prescribing and safety?
- Numerous studies have demonstrated non-medical prescribing is safe and equivalent to traditional care systems
- Patients report greater flexibility, easier access to care and that chronic conditions are better managed
- Greater professional autonomy and broader opportunities
What are the (4) classifications of medicines?
- Prescription Only Medicine (POM)
- Pharmacy Medicine (P)
- General Sales List Medicine (GSL)
- Over The Counter Medicine (OTC)
Glucocorticoids.
What are they used for (purpose & conditions)?
– reduces bone density and adrenal insufficiency resulting in osteoporosis, increased fracture risk and joint pain.
(Asthma, COPD, arthritis, Crohn’s disease)
Steroids
What are they used for (purpose & conditions)?
– after 3/12 can cause reduction in bone density, osteoporosis
(asthma, MS, RA, other inflammatory conditions)
Statins
What are they used for (purpose & conditions)?
– myopathy, mostly mild but occasionally severe
(reduce cholesterol, cardiovascular disease)
Beta-blockers
What are they used for (purpose & conditions)?
– muscle cramps and mild muscle pain
(cardiovascular disease)
Hormones related drugs
What are they used for (purpose & conditions)?
– muscle cramps and mild muscle pain
(contraceptive pill and HRT)
