SCRIPT Questions Flashcards
What is the difference between antimicrobials and antibacterials?
Antimicrobials - act against all microbial organisms - bacteria, viruses, parasites and fungi.
What are examples of bacteriostatic ABs?
Clarithromycin
Doxycycline
What are examples of bactericidal antimicrobial agents?
Phenoxymethylpenicillin
Ciprofloxacine
Metronidazole
Vancomycin
Gentamycin
When can IV antimicrobials be switched to the oral route?
48-72 hours if P has improved clinically and can tolerate oral meds.
When should antimicrobials be reviewed?
48 hours after starting
- change the route?
- change the antibacterial?
- continue treatment?
- outpatient therapy?
Do you need to check serum gentamicin after the initial dose?
Not after one dose - unless there is a plan to give further doses.
Should check be checked x2 per week (more in renal impairment).
Which is the most appropriate AB to follow a gentamicin dose?
Ciprofloxacin
What is the risk of ciprofloxacin?
It can put elderly Ps at risk of contracting C Diff
In what situation should you start antimicrobials?
When there is clear evidence of infection.
If you identify Red Flag Sepsis or septic shock or life threatening infections, when should you start antimicrobials?
Within the hour.
What is the name of the PHE toolkit towards the use of antimicrobials in hospitals?
Start SMART then FOCUS
What is the difference between gram negative and gram positive organisms?
Gram negative have a thinner cell wall - made of less peptidoglycan and more LPS.
What type of bacteria is E coli?
Gram negative
What type of bacteria is Staph aureus?
Gram positive
Does Vancomycin have activity against G -ve, G +ve or both?
G +ve only
What are the three main antibacterial targets in bacteria?
Cell wall & membrane
Protein synthesis inhibition
DNA/RNA inhibition
Which type of ABs inhibit cell wall formation = rapid death of the organism?
Βeta-lactams
Which ABs inhibit a different stage of cell wall formation than β lactams and, when given in high concentrations, cause cell death?
Glycopeptide antibacterials
How do ABs prevent protein synthesis?
Bind to bacterial ribosomes and interfere with their function.
Which types of ABs prevent protein synthesis?
Macrolides (e.g. clarithromycin)
Tetracyclines (e.g. doxycycline)How
Aminoglycosides (e.g. gentamicin)
How do quinolones work?
They interfere with DNA synthesis (e.g. ciprofloxacin)
How does Metronidazole work?
Damages bacterial DNAW
Which types of bacteria does metronidazole work against?
Anaerobic bacteria
How does trimethoprim work?
Interferes with bacterial folate metabolism, resulting in a lack of analogues for DNA synthesis
How does daptomycin work?
It binds to bacterial membranes, leading to depolarisation of the membrane - causes rapid inhibition of protein, DNA & RNA synthesis = cell death
Name 4 classes of ABs which work against bacterial cell walls?
Carbapenems
Cephalosporins
Glycopeptides
Penicillins
Name 3 classes of ABs which work against bacterial protein synthesis?
Aminoglycosides
Macrolides
Tetracyclines
Why are G -ve organisms harder to destroy than G +ve ones?
They have a tough and relatively impermeable outer membrane, which restricts the passage of molecules through it = degree of protection. This is absent in G +ves.
How do the following work to convey defences against ABs:
- Efflux pumps
- Antibacterial-modifying enzymes
- Mutations
Efflux pumps = pump antibacterials back out of the cell before they reach the target site.
AB-modifying enzymes = destroy the AB before it reaches its target
Mutations = in the target side prevent an BA binding
Give an example of a bacterial which has an adapted efflux pump for increased resistance?
Pseudomonas aeruginosa
Give an example of a antibacterial-modifying enzyme?
Βeta-lactamase
Aminoglycoside-modifying enzymes
Give an example of a bacteria which has undergone mutation to prevent the AB from binding to it?
MRSA
What should you use when you prescribe ABs for reference?
Local guidelines
- take into account local resistance
- limit inappropriate use of broad-spectrum agents
- ensures adequate supply in the hospitals
- promotes cost-effectiveness
Why do we treat infection empirically?
Because you can’t know for sure which bacterium is causing the illness - therefore you use experience to determine which is the most likely cause and treat that first.
What is the difference between empirical treatment and directed therapy?
Empirical treatment = when you use best educated guest to target the cause
Directed therapy - when you have identified the cause before you treat
What is the possible disadvantage to using broad-spectrum ABs?
Indiscriminate use can result in adverse effects such as the development of multi-drug resistant strains and C-Diff.
What is the difference between
- susceptible
- susceptible at increased exposure
and
- resistant
organisms?
Susceptible = good likelihood of AB being successful at standard dosing
Susceptible at increased exposure = likely that the AB will be successful if a higher dosing regimen is used
Resistant = likelihood of failure if the AB is used at any dose to treat the infection
What information should you give microbiology about a patient?
- Previous colonisation and/or infection of organisms
- Any known allergies
- Any recent hospitalisation
- Any recent procedures or surgery
- Any recent travel or relevant social Hx
- Any obvious source of current infection
What do you need to document on the chart when prescribing ABs?
Indication for them
Intended route
Duration - inc stop date. Specify a review date as well.
Any intended change in route
What is the CURB-65 score used for?
Estimating mortality of pneumonia to decide whether to treat as inpatient or outpatient
Which infection is strongly associated with Co-Amoxiclav and which population are at greatest risk of developing the disease?
C Diff
Older patients
How should you treat a C Diff infection?
Stool cultures
Stop possible ABs which are causing it
If ABs still needed - use a narrow spectre
Empirical metronidazole should be started whilst awaiting stool culture
Exclude colitis & TMC if there is abdominal pain and pyrexia
Assess for sepsis
What is the downside of a
- subtherapeutic dose
- supra therapeutic dose?
Subtherapeutic = may not adequately treat infection - causing P’s deterioration
Supratherapeutic = can cause nausea & diarrhoea, renal or hepatic impairment.
Why does gentamicin need to take into account lean body weight and renal function when calculating the dose?
To avoid toxicity
What can excessive IV vancomycin cause?
Nephrotoxicity
If AB is not even, what is the potential consequence?
It can cause a supra therapeutic concentration - increasing the risk of toxic effects.
Can also cause a sub-therapeutic concentration.
How can you determine whether to give oral or IV Abs?
If mild infection - can normally give oral if P can tolerate.
If systemic infection - IV required initially to ensure adequate drug concentration is distributed in the tissues.
Exception - if there are deep infections - long courses of IV ABs may be needed.
If the drug has good bioavailability when taken (e.g. levofloxacin) - may not need to use the IV route
What examples of deep infections can you think of?
Infective endocarditis
Osteomyelitis
If ABs are given for too long - what can be the consequences?
Nausea
AB associated diarrhoea
C Diff
What is de-escalation treatment?
When you give a strong IV AB initially and then when the P is stable, you de-escalate the therapy by
- Stopping the AB
- Switching from IV to oral route
- Change the AB
- Continue and review again in 72 hours
- Refer to outpatient parenteral therapy
Which illnesses are mostly self-limiting that do not require AB therapy?
Acute cough
Acute otitis media
Acute sinusitis
Acute sore throat
What is delayed AB prescribing?
Used in the management of conditions which are usually self limiting - can give P a prescription and tell them to cash it only if they get worse.
Which guidelines are used to determine if a patient with a sore throat needs ABs?
FeverPAIN score
When should ABs be prescribed for sore throats?
P has systemic symptoms
Signs and symptoms of a more serious illness
At high risk of serious complications (e.g. valvular heart disease, immunocompromised)
What can you recommend to a P who isn’t given ABs for a sore throat?
Analgesia = paracetamol / ibuprofen
Salt water gargling
Medicated anaesthetic sprays
Maintain adequate fluids
Would you give co-amoxiclav together with trimethoprim for a possibly UTI and chest infection?
Wouldn’t need to give the trimethoprim as the Co-amox is broad spectrum and would be active against most of the organisms which cause UTIs.
Are urine dipsticks reliable diagnostics for catheter related UTIs?
No - catheters are quickly colonised with bacteria - and the dipstick will detect their presence (after 1 month almost all Ps with a long term catheter will have bacteriuria)
When should ABs be prescribed for UTIs in Ps with long term catheters?
What should you do in these cases?
When they have symptoms of a UTI.
Need to remove the catheter if possible and send urine sample of cultures and sensitivity.
How can you get restricted ABs prescribed?
Speak to senior member of the team and then discuss with microbiology who can advise.
If a patient needs an AB - when should the first dose be given?
As soon as possible - and then staggered so the next few doses come into line with the recommended dosing interval to prevent uneven distribution of dosing.
Out of the following which need to be taken with food, on an empty stomach or it doesn’t matter?
- Phenoxymethylpenicillin
- Metronidazole
- Nitrofurantoin
- Amoxicillin
- Trimethoprim
Phenoxymethylpenicillin = empty stomach
Metronidazole & Nitrofurantoin = just after food
Amoxicillin and Trimethoprim = either before or after food
Which dose units are permitted to be abbreviated on a drug chart?
Grams and Milligrams
Is it a legal requirement that the form (e.g. tablets) of the drug be stated on a prescription?
Yes
Which guidance covers authorisation of medicines for human use in the UK?
Human Medicines Regulations 2012
What does NMP, SP and IP mean in terms of staff?
NMP = non-medical prescriber
SP = supplementary prescriber
IP = independent prescriber
What is a PSD? When can you verbally use them?
Patient Specific Direction
Used in emergency situations to administer a medication to a named patient and this is then retrospectively documented.
Inpatient drug charts are patient specific directions = effectively an order to administer to a named patient.
What does TTO and TTA stand for?
Acronyms for discharge summaries - TTO = to take out, TTA = to take away
For what duration should you prescribe drugs post hospital release?
Varies but on TTOs usually min of 14 days is recommended
Can a computer generated signature be used on a FP10 prescription?
No - must be handwritten
When is it a legal requirement that the patient’s age is stated on the prescription?
When they are under 12
Over 12 - is good practice but not a legal requirement
Is it a legal requirement for a date of birth to be stated on an inpatient drug chart?
No - but good practice to do so to help verify patient details.
Not a legal requirement because the drug chart is a patient specific direction - so is an order for administration, not a legal prescription
What are the legal requirements of information that needs to be included on a prescription?
Age if under 12
Patient details - name, address & NHS number
Signature of Prescriber
Today’s Date
Name and address of prescriber - can include GMC number
Dose
Form of preparation (tablets, capsules, oral liquid) - even if one form is available
Strength
Total quantity of the number of dosage units in both words and figures
How long are prescriptions valid for?
For 6 months from issue
Which acts classifies controlled drugs?
Misuse of Drugs Act 1971 (Class A - C)
Which act defines who is authorised to supply and posses controlled drugs?
Misuse of Drugs Regulations 2001
Can F1s prescribe controlled substances?
No
How do you know if a drug is controlled?
Has the symbols CD2 and CD3 next to the drug name in the BNF
What is the total quantity on a prescription?
The number of dosage units - to be given in both words and figures.
For solids - prescribe the number of dosage units in both words and figures.
E.g. Morphine sulfate MR capsules 10mg BD, Supply 14 (fourteen) capsules
For liquids - prescribe the total quantity in both words and figures.
E.g. Morphine sulfate concentrated oral solution 100mg/5ml - 1ml four times a day when required for breakthrough pain. Supply 30 (thirty) mls
When prescribing controlled drugs, how long should you prescribe for?
Do not exceed more than 30 days. Often hospitals will limit to 7-14 days.
What is an unlicensed medicine?
When are they prescribed?
One that does not have a UK marketing authorisation
To fulfil special patient needs where a licensed product is not available
What is off-label prescribing?
Use of a medicine that does have marketing authorisation but is used in terms outside of its licence - e.g. at a difference dose, indication or patient group
What do you need to do when prescribing unlicensed or off-label medicines?
Makes sure that there is no suitable licensed alternatives and that there is a clear evidence base to support use.
Which medicines should be prescribed by brand?
Biologics
When a critical dose is required and different manufacturers have different release mechanisms / bioavailability profiles
What are the two main fluid compartments?
Intracellular and extracellular
Extracellular divide into interstitial and intravascular compartments
What do colloid fluids contain?
Large water insoluble molecules- e.g. carbs or gelatins