Pharmacology 1 Flashcards
What is meant by drug interactions?
- How different medications work together and how they affect each other
What is warfarin used for?
- Anticoagulant
- Used to treat and prevent blood clots that might result in heart attack, stroke or death
What is Carbamazepine used for?
- anticonvulsant
- It works by decreasing nerve im pulses that cause seizures and pain
What is convulsion?
- A sudden, violent, irregular movement of the body, caused by involuntary contraction of muscles and associated especially with brain disorders such as epilepsy, the presence of certain toxins or other agents in the blood or fever in children
What is an anti-coagulant?
- Drugs that help to prevent blood clots
What are the 5 different classes of drugs?
- Local anaesthetics
- Antimicrobials
- Drugs in pain and inflammation
- Drugs in sedation
- Emergency medical drugs
What is the use of local anaesthetic?
Used to reduce the awareness of pain
How does local anaesthetic work in terms of ion channels?
- Acts on nerve ion channels to block propagation (stops the signal from passing through nerves)
What are 4 examples of LA’s?
- Lignocaine
- Prilocaine
- Bupivicaine
- Mepivicaine
What are the properties of the LA mepivacaine?
- Rapid onset
- Intermediate duration
What are the 3 types of antimicrobial?
- Antibiotics
- Antiviral
- Antifungals
What are 4 commonly prescribed antibiotics?
- Amocycillin
- Metronidazole
- Doxicycline
- Clindamycin
What does amoxycillin do?
- Inhibits cell-wall synthesis during bacterial multiplication, leading to cell death
- It shows enhanced activity towards gram-negative bacteria compared to natural and penicillinase-resistant penicillin’s
What does metronidazole do?
Disrups DNA synthesis in susceptible bacterial organisms
What does Doxicycline do?
- Works against a wide range of gram-positive and gram-negative bacteria
What does Clindamycine do?
Used to treat gram-positive penicillin-resistant infections
What is Aciclovir?
- An antiviral drug
- It is highly active against the herpes simplex virus which causes cold sores and genital herpes and against the similar varicellszoster virus which causes chickenpox and shingles
What is Nystatin and what is it used to treat?
- Topical antifungal drug
- Used in treatment of infections due to candida species
What is Fluconazole and what is it used to treat?
- systemic - oral antifungal drug
- Used in the systemic treatment of candidiasis and cryptococcal meningitis
What is an analgesic?
A medicine that relieves pain
What are the drugs used to reduce inflammatory mediators?
- Non-steroidal anti-inflammatory drugs (NSAID)
What are the drugs used to reduce the inflammation process?
- Corticosteroids
What does anti-pyretic mean?
Reduces the effects of fevers
What are the properties of paracetamol? (3 points)
- Anti-pyretic and analgesic
- Little anti-inflammatory action
What is the mechanism of action of paracetamol?
- Mechanism uncertain
Does paracetamol have many side-effects?
No, has few side effects
Is there a restricted sale of paracetamol?
No
What is the dosage for paracetamol?
Dose 1g, four times daily
Paracetamol is often combined with other analgesics. What is a common combination?
- Co-codamol
- Paracetamol and codeine
- This is more effective than just giving one or the other
What is an example of a Salicylate and what is it used for?
- Aspirin
- Used to relieve pain, reduce inflammation and lower fever
Give an example of a propionic acid derivative?
- Ibuprofen
Give an example of a phenylacetic acid derivative and explain what these do?
- Diclofenac
- Works by reducing substances in the body that cause pain and inflammation
What is the action of NSAID’s?
- True action unknown
- Inhibit prostaglandin synthesis (prostaglandins are large mediators of change across the body)
Which enzyme do NSAID’s inhibit?
- Cyclo-oxygenase (COX) enzyme
Which acid do drugs for pain usually inhibit?
- Arachidonic acid
What is Arachidonic Acid?
- It is an unsaturated fatty acid found in most/all plasma membranes, where it is bound to phospholipids
Are the hormones made from arachidonic pro-inflammatory or anti-inflammatory?
- Proinflammatory
What are some of the actions of prostaglandins? (6 points)
- Constriction or widening of arteries
- stimulate pain nerve endings
- Promote or inhibit aggregation of blood platelets and hence influence blood clotting
- Induce abortion
- Reduce stomach acid secretion
- Relieve asthma
Is aspirin available without restriction?
Yes
What is the recommended dose for aspirin?
- 300-600mg up to 4 times daily
What is pharmacokinetics?
- The study of the movement of drugs in the body, including the processes of absorption, distribution, localization in tissues, biotransformation and excretion
Where in the body is aspirin rapidly absorbed?
- The GIT
Aspirin is eliminated by 1st order kinetics. This means it is rapidly absorbed by the body. There is one exception to this, what is the exception?
- Overdose of drug (enzyme saturation)
- This can have toxic effects - acidosis
What is acidosis?
- The accumulation of acid or depletion of the alkaline reserve in the blood and body tissues, leading to a decrease in the pH
Aspirin inhibits the action of COX1, what are the consequences of this?
- Reduced synthesis of prostaglandins
- Reduced production of inflammatory mediators
- Anti-pyrexic (reduces fever)
What is meant by the term ‘anti-pyrexic’?
- Reduces fever
Aspirin can be taken before the inflammatory process starts. What is the term to describe this?
- PRE-EMPTIVE analgesia
What are the possible side effects of taking aspirin? (5 points)
- Gastric irritation - erosion, ulceration (made worse with alcohol)
- Inhibition of platelet function (enhanced bleeding)
- Bronchospasm (exacerbate asthma)
- Allergic reaction (rash)
- Drug interactions (significant protein binding - WARFARIN potentiation)
Which drug is known to interact with aspirin?
- Warfarin
Is ibuprofen sold with restriction?
No
What category of drug does aspirin fit into?
NSAID (non-steroidal anti-inflammatory drug)
Which drug has similar actions to ibuprofen?
- Aspirin
- Fewer side effects than aspirin (same effects but less problematic)
What is the recommended dose for ibuprofen?
- 200-600mg, three times daily
Is Diclofenac a restricted sale drug?
- Yes, it is only available on prescription
Diclofenac is more potent than ibuprofen. Why is this? (3 points)
- Higher incidence of gastric bleeding
- Higher incidence of asthma triggering
- Allergic reactions (rash)
BUT has a more effective anti-inflammatory action
What is the recommended dose for Diclofenac?
50mg, three times daily
Corticosteroids reduce inflammation. How do they do this?
By inhibiting:
- Capillary permeability
- Formation of bradykinin
- Migration of white blood cells
- Reduce eicosanoid synthesis
What is eicosanoid?
- Any group of substances that are derived from arachidonic acid, including leukotrienes, prostaglandins and thromboxanes
Corticosteroids suppress the features of inflammation but what do they not do?
- They do not actually address the cause
Corticosteroids can be topical or systemic. What does this mean?
Topical
- On the surface of the desired tissue
Systemic
- Given to the whole organism
Give 2 examples of topical corticosteroids?
- Steroid inhalers in asthma
- Hydrocortisone cream for eczema
What are 3 examples of steroid treatment for mouth ulcers?
- Beclomethasone inhalers
- Hydrocortisone adhesive tablets
- Betamethasone solutions
Are systemic corticosteroids commonly prescribed by dentists?
- No, as there can be a lot of side-effects
One example of a systemic corticosteroid is Prednisolone (tablets). What can this be used to treat? (2 points)
- Prevent transplant rejection
- Treat immunological diseases
One example of a systemic Corticosteroid is Dexamethasone (injection). What is this used to treat? (1 point)
- To reduce swelling after surgery e.g.wisdom tooth removal
What are the side effects of taking systemic steroids? (7 points)
- High blood pressure
- Weight gain (fluid)
- Fat distribution change (centripital obesity + ‘buffalo hump’)
- Gastric ulceration
- Adrenal suppression
- Osteoporosis (when bones become brittle and fragile)
- Diabetes
What is centripetal obesity?
- When excess weight gain is held around the mid section of the body
What is the term used to describe drugs that are used to reduce the effects of anxiety?
Anxiolytics
What are 2 examples of drugs that are anxiolytics (drugs used to reduce anxiety)?
- Benzodiazepines (diazepam, midazolam)
- Gas (nitrous oxide)
What is the mechanism of action of Benzodiazepine and what are the side effects of taking them? (Long answer)
- Act directly on an inhibitory neurotransmitter of the brain known as GABA, binding to specific receptors of GABA and acting as a GABA agonist
- This means that when benzodiazepines reach the brain regions, they increase the activity of GABA and therefore increase the inhibitory postsynaptic potentials
- The main advantage of benzodiazepines is that when they act on GABA they increase the frequency of opening of the chlorine channel
- Thus, these drugs are not capable of providing greater activation than would achieve by the GABA alone, so the risks of its consumption are low
- The longer you take them for, the less active they will be
- When you stop taking them they have a reverse effect and make the problem worse
What is the mechanism of Benzodiazepine metabolism?
Phase 1 - conversion to metabolites of lesser, equal or greater extent (e.g. diazepam, chlordiazopexide, clobazam)
Phase 2 - Conversion to inactive metabolites (e.g. Lorazepam, Oxazepam, Temazepam)
What happens in the first phase of Benzodiazepine metabolism?
- Oxidation, hydroxylation, dealkylation, reduction
What happens during phase 2 of Benzodiazepine metabolism?
- Glucuronisation, conjugation or acetylation
How is Nitrous Oxide administered?
- Inhalation sedation (inhaled as a gas)
- No needle techique
Are there organ metabolism issues when giving a patient Nirtous Oxide?
- No, it is excreted unchanged as a gas
Which conditions require medical emergency drugs?
- Asthma
- Heart attacks
- Diabetic emergencies
- Seizures
- They all require medicine - kept in a lit with other emergency treatment aids
Why can Nitrous Oxide not be given to a patient who is pregnant?
- It interferes with Folic Acid metabolism
