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)
Diuretics
What are they used for (purpose & conditions)?
– muscle cramps
(Oedema treatment, kidney disease, CV problems)
What are the main pathologies statins are used to treat?
- Coronary heart disease(when the blood supply to the heart becomes restricted)
- Angina(chest pain caused by reduced blood flow to the heart muscles)
- Heart attacks(when the supply of blood to the heart is suddenly blocked)
- Stroke(when the supply of blood to the brain becomes blocked)
What do statins do?
Help lower level of low-density lipoprotein (LDL) cholesterol in the blood (which can lead to a hardening and narrowing of the arteries – causing CVD)
How do statins work?
- Reduce amount of cholesterol produced by the liver, and remove it from the blood
- Reduce risk of heart attack and stroke
What are some side effects of statins?
- Muscle aches (myalgia)
- Weakness & cramps
- Vomiting
- Nausea
- Diarrhoea
- Constipation
- Can cause liver damage or muscle breakdown (in rare cases)
How do statins affect participation/what precautions should be taken?
- Assess tendon health
- Educate patients on symptoms
- Consider fatigue & recovery
- Be cautious of high intensity exercise
- Pain
What pathologies are Ace Inhibitors used to treat?
- Hypertension
- Heart Failure
- Heart Attack
- Kidney Disease
- Coronary Artery Disease
- Diabetes
- Scleroderma
- Glomerular disease
- Albuminuria
How do Ace Inhibitors work?
- Stops body producing angiotensin II (a hormone), lowering the amount in your blood
- Makes muscles in blood vessel walls contract, vasoconstricting
- Angiotensin II acts on kidneys –> keeping water in blood stream rather than releasing into urine
- With more fluid in the blood there is more pressure on the blood vessel walls
- Allows blood vessels to relax and widen, and for fluid to be removed from blood and released into urine, lowering blood pressure
What precautions should be taken with patients on Ace Inhibitors?
- Reduce sudden movement (i.e.: sit to stand)
- Fall risk, so extra management of the environment (tidy floors and space to walk)
- Measures should be taken to not raise their blood pressure too high
What are the side effects of Ace Inhibitors?
- Affecting energy levels
- Balance
- Endurance
- Persistent dry cough
- Headaches
- Blurred vision
- Angioedema (swelling of the face, neck and mouth)
- Dizziness (due to low blood pressure)
- Loss of taste
- Kidney problems (e.g.: proteinuria)
- Severe stomach pain
What pathologies can Calcium Channel Blockers be used to treat?
- Coronary artery disease
- Angina
- Arhythmia (irregular heartbeat)
- Hypertension
- Raynauds phenomenon
What are the side effects of Calcium Channel Blockers?
- Constipation
- Dizziness
- Fast heartbeat you can feel
- Extreme tiredness
- Flushing
- Headache
- Nausea
- Swelling (in feet and lower legs)
- Breast cancer risk (if used long term)
What precautions should be taken when a patient is on Calcium Channel Blockers?
- Check vital signs (i.e.: blood pressure) before & after physical activity to avoid hypotension or aorthostatic hypertension, which can cause dizziness and fainting when standing up or lying down (provide assistance and do it slowly)
- Gradually increase physical activity (can cause dizziness and light-headedness, affecting balance + coordination, increasing fall risk).
- Monitor for swelling (can cause peripheral oedema). This can affect mobility and comfort during physiotherapy
What are medications which can masquerade as an MSK problem?
- Glucocorticoids
- Steroids
- Statins
- Beta-blockers
- Hormones
- Diuretics
