Top 100 Drugs Flashcards
What are Analgesics?
These are painkillers
Unlike medicine used for anaesthesia, these don’t turn off your nerves, change the ability to sense your surroundings or alter consciousness
What are the common indications of paracetamol?
-Paracetamol is the first-line analgesic for most forms of acute and chronic pain
The WHO pain ladder uses paracetamol as the basis treatment, with weak then stronger opioids added incrementally until pain is controlled
- is an antipyretic that can reduce fever and it’s associated symptoms e.g. shivering
What are antipyretics?
A substance that is used to reduce fever
What are prostaglandins?
A group of lipids with hormone-like actions that your body makes primarily at sites of tissue damage or infection
What is the mechanism of action for paracetamol?
It is a weak inhibitor of cyclooxygenase (enzyme involved in preostaglandin metabolism)
In the CNS, COX inhibition increases pain threshold and reduces prostaglandin concentrations in the thermoregulatory region of the hypothalamus- controlling fever
Paracetamol is a weak anti-inflammatory
Does paracetamol have a higher specifity for COX-1 or COX-2? Explain why this is significant.
-Higher specifity for COX-2 (isoform induced in inflammation), rather than COX-1 (the isoform involved in protecting the gastric mucosa and regulating renal blood flow and clotting).
-Despite it’s COX-2 selectivity, paracetamol is a weak anti-inflammatory, as it’s actions are inhibited in anti-inflammatory lesions by the presence of peroxides
What are adverse effects of paracetamol?
-at treatment dose paracetamol is very safe with few side effects
-in overdose paracetamol causes liver failure
What are some warnings of paracetamol?
Reduced paracetamol dose should be given in people with increased risk of liver toxicity because of:
Excessive alcohol use
Malnutrition
Low body weight
Severe hepatic empirment (especially important when given as IV infusion)
What are some important interactions of paracetamol?
Cytochrome 450 inducers- these are the enzymes which metabolises paracetamol and produces NAPQI, too much NAPQI causes a risk of liver toxicity
What are some things you should communicate with the patient when giving paracetamol?
-giving paracetamol with the aim to reduce pain
-effects will be felt around half an hour after taking it
-warn them not to exceed the maximum daily dose because of risk of liver poisoning
-many medicines purchased from pharmacies contain paracetamol so make sure to not this with paracetamol
How can you determine the efficacy of paracetamol?
Monitor the pain after 1-2 hours after taking the paracetamol (acute pain)
For chronic pain, schedule a review to assess the need to step or down the analgesic ladder
What are common indications of penecilins?
-streptococcal infections e.g. tonsillitis, pneumonia, endocarditis, skin and soft tissue infections
-clostridial infection e.g. tetanus
-meningococcal infection e.g. meningitis, septicaemia
What is the mechanism of action for penicillins?
-they inhibit the enzymes responsible for cross-linking peptidoglycans in bacterial cell wall
-this weakens cell walls, preventing them from maintaining an osmotic gradient
-uncontrolled entry of water into bacteria causes cell swelling, lysis and death
What is the mechanism of resistance of bacteria from penicillins?
-penicillins contain a beta lactase ring, this is responsible for their antimicrobial activities
-bacteria resist the action on penicillins by baking beta lactamase, an enzyme which breaks down the beta lactation ring and prevents antimicrobial activities
What are important adverse side-effects of penicillins?
-penicillins allergy effects 1-10% of people
-usually presents as a skin rash 7-10 days after exposure or 1-2 days after repeat exposure
-a less common but immediate side effect is an anaphylactic reaction this can occur with hypotension, bronchial and laryngeal spasm, oedema and angioedema
-CNS toxicity can occur with high doses
