PSA Flashcards
What is d dimer
What is a positive result
What does it tell you
Fibrin degradation product
Positive if it is raised
Suggests there may be a clot
what are the different types of anticoagulants
Vitamin K antagonists
Direct thrombin inhibitors, direct Xa inhibitors (DOACs)
Indirect Xa and thrombin inhibitors - Heparin
give some examples of direct thrombin inhibitors
dabigatran, edoxaban
give some examples of direct xa inhibitors
apixaban, rivaroxaban
give some examples of direct xa inhibitors
apixaban, rivaroxaban
what patients should DOACs not be used in
antiphospholipid syndrome
caution - elderly
renal impairment, egfr <15
What are some limitations / considerations with warfarin
Narrow therapeutic window
Frequent monitoring and dose adjustment
Interaction with food and drugs, chemotherapies
Less effective than LMWH for patients with cancer
what should you consider when deciding anticoagulant for DVT/ PE treatment
Renal function
Active cancer
Antiphospholipid syndrome
what blood test is used to measure warfarin and extrinsic pathway
prothrombin time
what blood test is used to measure heparin and intrinsic pathway
activated partial thromboplastin time
what is warfarin most commonly prescribed for
AF
Heart valves
VTE prophylaxis
what do you need to consider in a patient with cancer if wanting to anticoagulate
account tumour
site, drug interactions
including cancer drugs,
and bleeding risk
what is a side effect of unfractioned heparin
heparin thrombocytopaenia (dont get this with LMW heparin - dalteparin)
what is a normal INR
what is a target INR for those on warfarin
Normal <1.1
On warfarin 2-3
what vte prophylaxis should be used in pregnancy and why - what about those currently on warfarin for heart valve anticaog
LMWH, does not cross placenta and not in breast milk
Warfarin teratogenic
what anticoagulantion is generally used for treatment of an acute venous thrombotic event and why, what are exceptions
LMWH or DOAC - faster to work than warfarin
Can use warfarin if problem with renal function - need more monitoring and dose adjustments
what anticoagulation is generally used for short term vte prophylaxis, give some examples of clinical sceanarios
LWMH or DOAC eg post surgical prophylaxis, pregnancy (LMWH)
what anticoagulation is generally used for long term vte prophylaxis and why
DOAC or warfain
Both oral
list some conditions where warfain is the only anticoag indicated
Heart valve vte prophylaxis
AF (sometimes, only if DOAC is problem)
what conditions should you consider when deciding about anticoag
Renal function
Age - elderly (caution DOACs)
Cancer (DOACs interact w certain chemos)
Antiphospholipid (DOAC contraindicated)
What is the mode of action of tranexamic acid
Antifibrinolytic
Binds to plasminogen and inhibits it so plasmin not secreted = fibrin mesh stays in place and prevents bleeding
What are the adverse effects of aminoglycosides
Kidney injury
Hearing changes / loss - can affect cochlear
What group of patients are aminoglycosides contraindicated in
Myasthenia gravis
What is a loading dose and why is it used
It is a high dose of a drug that is used to build up plasma concentration faster than a lower dose
The ‘steady state’ of a drug - which is when plasma concentration production and elimination are matched, if you aim to reach steady state with low dose it will take a while to get there. If use a higher dose you push the start point up so that you can then use a lower dose later to maintain.
Example - 300 mg aspirin, followed by 75 mg maintenance
what are the contraindications to NSAIDS
GI bleed Ulcer Asthma Severe heart failure Cerebrovascular event
what should you check with prescribing paracetamol
liver function
severe cachexia
what should you check before prescribing nsaids
renal function platelets any blood thinners digoxin - dose needs adjusting down steroids - increased risk of gi bleed
what is the risk of nsaids during pregnancy
first trimester miscarriage
third trimester - closure of ductus arteriosus, risk of pulmonary hypertension
List the common nephrotoxic drugs
ANA Antihypertensives NSAIDs Aminoglycosides (perfusions/ acute tubular necrosis)
Which drugs can cause a metabolic acidosis because of effects on kidney
Metformin
Diuretics (reduced bicarb absorption and increase in Cl)
NaCl - raised Cl
List some drugs that can cause electrolyte dysfunction via kidneys and may need dose adjustments
(all affect K or Na via action on kidneys)
Trimethoprim - hyperkalaemia
Ampherotericin B - anti fungal
Litium - hyponatraemia
Immunesupression - ciclosporin, tacrolismus
Digoxin - hyperkalaemia
What is the mechanism of NSAIDs, how does this link to the types available to prescribe
NSAIDs inhibit prostaglandin production via inhibition of COX-1 or COX-2 enzymes that convert aracidonic acid to prostaglandins.
COX-1 pathway involved in homeostasis
COX-2 pathway involved in inflammation
There are NSAIDs that have mixed COX-1 and COX-2 actions, and some selective COX-2 (coxibs) - celecoxib and etoricoxib
what are the common sides effects of NSAIDs and why
- GI bleed - via effects on COX-1 pathway
- Nephrotoxicity - via afferent arteriole vasoconstriction and under perfusion leads to low GFR
- HTN - via loss of prostaglandin vasodilation
what are some of the complete contraindications to NSAIDs
Previous GI bleed
Severe HF
eGFR <30
Uncontrolled hypertension
what is a life threatening allergy that you should check for before starting any nsaid
asthma - can have allergy to nsaid
what are common drug interactions with nsaids
digoxin (raised BP)
steroid (immune supression effect?)
other NSAIDs
List some common non-specific NSAIDs
Aspirin Ibuprofen Mefanamic acid Diclofenac Indometacin Naproxen
List some cox-2 specific NSAIDs
Coxibs
Celecoxib
What process should you use to consider if a patient is eligible/ should be started on an NSAID
- Systems contraindications - stomach, kidneys, blood, airways (previous bleed, gfr <30, uncontrolled htn, previous CVD/ PVD, asthma)
- Drug contraindications - another nsaid, digoxin, steroid
Then categorise as high, medium, low risk for adverse event
How should you manage high, medium and low risk of adverse event (bleed) when prescribing NSAIDs
High risk - cox-2 only plus PPI
Medium risk - cox-2 or nsaid plus ppi
Low risk - nsaid
If somebody has a hx of ischemic hd, cerebrovascular disease, of peripheral vascular disease - how should you prescribe an NSAID
There is a risk of HTN and bleeding with a non-selective NSAID
Should have low dose ibruprofen
COX-2 inhibitors and diclofenac are contraindicated in this group
Describe the analgesic ladder
Step 1: simple analgesia - paracetamol (check liver function and weight), NSAIDs
Step 2: weak opioids (codeine, dihydrocodeine, tramadol)
Step 3: strong opioids (morphine, oxycodone, diamorphine, bupronorphine)
what should a PRN dose of an opioid be
1/6th the total 24 hours dose
How should you work out opioid dose conversions
Opioid conversion chart
What is the difference in strength between codeine and morphine
morphine is 10x stronger, so need 1/10th of the dose
what are the common side effects of opioids
constipation nausea sedation dry mouth sometimes confusion sometimes respiratory depression
why is oxycodone preferable to morphine for some people
Less side effects
Double the strength of morphine
When filling out a prescription what do you need to ensure
Name of drug Suspension - immediate release, modified release, oral etc strength of tablet - eg 500 mg total dose - eg 1500 mg TDS Route - PO, IV, IM etc duration - how many days to take number of tablets to be dispensed
what do you need to check before prescribing opioids
renal function
need dose adjustments if impaired
need low dose and frequency
What antibiotics can be prescribed to breastfeeding mum with UTI
Amoxicillin (weak acid so doesn’t accumulate in breastmilk)
Cefalexin
Trimethoprim
What UTI antibiotic is contraindicated in breastfeeding and why
Nitrofurantoin - can cause haemolysis
Mechanism of action is DNA damage
Describe the first and second line treatments for type 2 diabetes
First line - metformin (need to check renal function, contraindicated if gft <30 and need reduced dose if gfr <45)
Second line - gliptins - DPP-4 inhibitors
Pioglitazone
Sulfonylureas
SGLT-2 inhibitors
What is a normal hba1c level
<42
42-46 - prediabetes
>47 - diabetes
What are second and third line treatments for type 2 diabetes
Two hypoglycaemics Metformin + second line Or Two second line Can then do triple therapy if needed Then insulin
In what clinical situations is insulin used
Type 1 diabetes
Type 2 diabetes- last resort
Pregnancy - gestational diabetes
Hyperkalaemia
rapid onset insulin - how quick does it work and how long
10-15 minutes onset
works 3-5 hours
list some of the rapid insulins
lispro (Humalog®), aspart (NovoRapid®) and glulisine (Apidra®)
what is the onset and duration of long acting insulin
1 hour
24 hours
taken once a day
list some long acting insulins
glargine (Lantus®) and detemir (Levemir®).
what is the onset and duration of short acting insulin
30 mins
8 hours
what is one of the issues of short acting insulin
can cause hypos in between meals
list some short acting insulin
Actrapid® and Humulin S®.
what is the onset and duration of intermediate insulin
1.5 hrs onset
24 hours duration
what things do you need to discuss with a patient regarding their insulin regimen choice
glycaemic control - different regimes have different outcomes with this
flexibility - basal bolus most adaptable but it requires the most input from patient
burden/ patient involvement - one or twice daily regimes are less burdensome but poorer control
How regular are meals
Are days predictable or unpredictable
what are the indications for an insulin pump
basal bolus regime not worked - poor glycaemic control
having hypos with multiple injection regime
why should you never omit insulin in a T1 diabetic
15 mins of no insulin can be enough to cause DKA
what are some of the indications of IV insulin
DKA, HHS ACS Post cardiac event if hyperglycaemia Surgery and diabetes High/ fluctuation glucose - eg sepsis
what is the traditional fluid regime
Saline 0.9% + 20mmol potassium chloride (over 8 hours)
Dextrose 5% + 20mmol potassium chloride (over 8 hours)
Dextrose 5% + 20mmol potassium chloride (over 8 hours)
outline an algorithm for fluid resuscitation/ prescribing / how to chose a regimen
- Are they hypovolaemic - yes - 500 mls NaCl (or Hartmann’s if vomiting as has K in)
- Once normovolaemic - review to identify any existing deficits or ongoing losses - add these to routine maintenance. Do same with electrolytes.
- Consider any special circumstances/ redistrubution - HF, Renal failure, sepsis, hyper/ hyponatraemia, refeeding syndrome
- Calculate maintenance fluids
How do you calculate maintenance fluids
30 ml/kg Or 25 mls/kg if elderly, HF or RF Use ideal BW if obese 1 mmol/kg/ day for Na+, K+, Cl- 50-100g glucose a day to prevent starvation ketosis
What needs to be filled in for a fluid prescription
Name of fluid - NaCl 0.9% Volume - 1000ml Rate - 8 hours Additives - eg K Route - IV
list some common causes for ongoing losses
drains - any including ng for decompression of bowel gi tract - bleed/ diarrhoea pyrexia tachypnea sweating urinary loss
When is adding glucose to fluids contraindicated
cerebral event - can make worse?
complications of fluid overload
pulmonary odema
dilutional hyponatraemia
what medical therapy should you give for IV fluid overload
Stop intravenous fluids
Furosemide: can be given as a bolus or infusion.
Sublingual nitrate: causes a reduction in preload, the effects of which can be seen within five minutes.
Intravenous nitrate: BP monitoring is essential with this intervention, as hypotension is an indication to stop the infusion.
Continuous positive airway pressure ventilation
What rate should blood transfusion be given
1.5-2 hours per unit
What rate should FFP and platelets transfusion be given
30 mins - 1 hr per unit
Within what time frame should blood be given after being removed from temp controlled storage
4 hours
what blood is given in an emergency when patient blood group is not known
O negative
O D negative blood (‘Flying squad / Emergency’) - immediate - 5 minutes
Group compatible blood (i.e. same group as patient) - 10 - 15 minutes
Fully crossmatched blood- 30 - 40 minutes (maybe hours if antibody found).
can platelets be stored in blood fridge
No - causes them to aggregate
what is the management of a mild transfusion reaction
MANAGEMENT OF A MILD TRANSFUSION REACTION
BSH (2012) recommend if you suspect a mild transfusion reaction:
STOP the transfusion
Seek medical advice immediately
Check it is the correct component for the patient: check blood component laboratory produced label against the patient’s identification band, and with the patient themselves (if possible).
Assess the patient
Treat the signs and symptoms of the mild reaction appropriately. An antipyretic or antihistamine may be required.
Do not use an antihistamine to treat a simple fever. In the event of a mild reaction, the transfusion can usually be restarted after 30 minutes if the patient has responded to symptomatic treatment.
The transfusion should not be restarted if the patient does not respond to treatment or if signs or symptoms worsen.
management of a moderate transfusion reaction
STOP the transfusion
Seek medical advice immediately
Check is it the correct component for the patient: check laboratory produced label attached to blood component against the patient?s identification band, and with the patient themselves (if possible)
Assess the patient
Bacterial contamination or acute haemolytic transfusion reaction may be considered here.
Treat the signs and symptoms of the moderate reaction appropriately. An antipyretic or antihistamine may be required.
The transfusion might be discontinued, or might be restarted following symptomatic treatment under close supervision, depending on type of reaction indicated.
presentation of a moderate transfusion reaction
Febrile reactions
A rise in temperature of 2oC or more, or fever 39oC or over and/or rigors, chills, other inflammatory symptoms/signs such as myalgia or nausea which precipitate stopping the transfusion (SHOT 2018)
Allergic reaction
Wheeze or angioedema with or without flushing/urticaria/rash but without respiratory compromise or hypotension (SHOT 2018)
An antipyretic or antihistamine may be required.
The transfusion might be discontinued, or might be restarted following symptomatic treatment under close supervision, depending on type of reaction indicated.
presentation of mild transfusion reaction
Mild
Defined as a temperature of = 38 oC and a rise between 1 and 2oC from pre-transfusion values, but no other symptoms or signs (BSH, 2012 SHOT 2018).
Allergic reaction
Mild
Transient flushing urticaria or rash (SHOT 2018)
Remember - do not use an antihistamine to treat a simple fever.
management of severe transfusion reaction
STOP the transfusion
Call the doctor to see the patient urgently
Check compatibility of unit: check the details on the component against the patient’s identification band, and with the patient themselves (if possible).
Assess the patient
Management (under medical direction)
Replace the administration set and preserve IV access with normal saline to maintain systolic BP
Assess the patient
Check urine for signs of haemoglobinuria
Commence appropriate treatment; Maintain airway and give high flow Oxygen. If appropriate administer adrenaline and/or diuretic and resuscitate if/as required.
Reassess patient and treat appropriately - Seek expert advice if patient’s condition continues to deteriorate.
what is haemolytic transfusion reaction
This is a rare type of transfusion reaction usually seen in patients who have developed red cell antibodies in the past from transfusion or pregnancy. A combination of the features occurs days after the transfusion, suggesting that the red cells are being destroyed abnormally quickly.
Signs and symptoms include:
Fever
Falling haemoglobin or a rise in Hb less than expected
Jaundice
Haemoglobinuria.
explain how insulin dosing is calculation
- BW calculation - 0.5 x bw if normal adult, 0.3 x bw if new TIDM, elderly, frail, any co-morbidities
- 6 hourly insulin dose on VRIII divided by 6 = hourly dose, x20 (not 24 bc of risk of hypo)
explain how total insulin dose is distributed throughout the day
If on twice daily injections - 60% AM, 40% PM
If on basal bolus - 50% background, remaining split 3 ways AM meal, lunch, and PM meal
what is the max paracetamol dose a day
If over 50g - 4g in 24 hours
how many hours should always be given between paracetamol administration, regardless of the dose
4 hours
Do overweight patients need higher paracetamol doses
No
What patient group is diclofenac contraindicated in
Cardiovascular/ cerebrovascular disease
Anybody with ischemic HD, cerebrovascular, peripheral vascular disease
What NSAID can be used in patients with cardiovascular and cerebrovascular disease
Low dose ibuprofen only (<1200 mg per day)
which nsaids have the lowest gi risk amongst nsaids
ibuprofen and etoricoxib
which nsaids have the highest gi risk amongst nsaids
aspirin and ketoralac
which nsaids have intermediate gi risk amongst nsaids
diclofenac and naproxen
what factors should you consider to prescribe nsaids safety
cardiovascular risk factors/ events ulcer/ bleeding risk asthma ckd blood thinners - never with warfarin severe liver disease
what is the difference in potency of codeine and dihydrocodeine
same potency orally
iv - dihydrocodeine is twice as potent
how do you convert tramadol to morphine
you cant
its conversion is not very reliable
have to consult pain team
how is morphine usually initially prescribed
immediate release (if dont have prn) - to calculate daily requirement, and then modified release when you know this prn only used for cancer pain
how is morphine usually prescribed for cancer pain
modified release plus prn
how should prn morphine dosing be prescribed
As the dose of the scheduled opioid is increased, the dose for breakthrough pain should be increased to maintain the dose as a percentage of the total daily dose.
what should always be prescribed with morphine when administered via pca
naloxone
what are the long term effects of opiates
immune suppression
addiction
what should you always check before prescribing codeine
if the patient is taking codeine from any other sources/ any other over the counter medicines
what is first line management of neuropathic pain
antidepressant or antiepileptic drug as first-line non-specialist treatment, either alone or in combination together with non-pharmacological management such as surgical treatment and psychological interventions.
second line management for neuropathic pain
alternative first line
what is adjuvant analgesia
Drugs with other indications that may be analgesic in specific circumstances. Some are licensed for specific analgesia, eg neuropathic pain
what two analgesics can cause serotinergic syndrome
tramadol and amitriptyline
contraindications to warfarin
Hypersensitivity
Haemorrhagic stroke
Clinically significant bleeding
Pregnancy (especially during the first and third trimester)
Severe liver disease
Severe renal impairment
Within 72 hours of major surgery, with severe risk of bleeding
Concomitant drug treatments where interactions may lead to a significantly increased risk of bleeding
Within 48 hours postpartum
what factors can increase sensitivity to warfarin
- Age over 70-years-old (especially those over 80-years)
- Drug interactions (e.g. amiodarone)
- Hepatic impairment (baseline INR > 1.4)
- Severe cardiac failure
- Total Parenteral Nutrition (TPN)
- Low albumin levels
- Low Body Mass Index (BMI)
what must you check before prescribing warfarin
What is the indication for treatment?
Do they need rapid or slow loading?
Are there any factors that would increase the patient’s sensitivity to warfarin?
A blood test to check their baseline INR.
The indication for anticoagulation and target INR documented in their medical/patient notes.
Their allergy status confirmed.
what book do people on anticoagulants have
yellow book
what factors increase sensitivity to warfarin
Age over 70-years-old (especially those over 80-years) Drug interactions (e.g. amiodarone) Hepatic impairment (baseline INR > 1.4) Severe cardiac failure Total Parenteral Nutrition (TPN) Low albumin levels Low Body Mass Index (BMI)
what is the onset and half life of DOACs, what is the clinical relevance of this
Onset 1-4 hours
half life - 14 hours
It means that any bleeding caused by them should stop after 24 hrs (i.e. you may not see deranged clotting if its 24hrs after event)
How are DOACs metabolised and excreted
All have varying liver metabolism and renal excretion
Dabigatran does not use CYP450
what are the indications for DOACs
VTE prophylaxis post knee and hip surgery
Treatment of DVT and PE
Stroke and emoblic event prevention in non-valvular AF, with one or more RFs
what are the indications for apixaban
vte prophylaxis knee and hip replacement
stroke and emboli prophylaxis non valvular AF
treatment of dvt and pe
prevention of recurrent dvt / pe
what factors affect the dose used for apixaban
age
weight
renal function
what factors indicate a dose reduction for apixaban
Age ≥ 80-years
Body weight ≤ 60 kg
Serum creatinine ≥ 133 micromol/litre
can doacs ever be prescribed with another anticoagulant
no
unless its to provide cover whilst switching to warfarin and waiting for inr to come into range
what are some drug contraindications with apixaban
caution/ dont use with other blood thinners - antiplatelets, nsaids, ssri’s, snri’s
should not be used alongside antifungals or hiv meds
what is the advise with missed apixaban dose
Advise patients who miss a dose to take the apixaban immediately and then continue with twice daily intake as before
which doac is most affected by renal impairment
dabigatran
because it is mostly renally excreted
CI when crcl <30
which doac can be prescribed alongside aspirin or aspirin plus clopidagrel (or other antiplatelet)
rivaoxaban
can be co-prescribed with antiplatelet in high risk angina and post acs (mi)
when should doacs be stopped and re-started perioperatively
can be stopped on day of surgery (i.e. last dose 24 hrs before surgery)
if low risk surgery can be re-started 6 hours post op
if high risk surgery more likely 48 hours - if high thrombosis risk LMWH prophylactic dose may be used before restarting doac
when should warfarin be stopped and re-started perioperatively
stopped 4-5 days before
can give lmwh if needed (high thombosis risk - give last dose d-1)
start lmwh 6-8 hrs post op (depending on bleeding risk and surgery done)
warfarin can be re-started d+1
does lmwh affect aptt
no - lmwh activity must be monitored by antiXa assay
only unfractioned heparin does
can lmwh cross placenta
no
list some of the contraindications to lmwh
Acute bacterial endocarditis Active bleeding Bleeding disorders (e.g. haemophilia) Hypersensitivity Severe hypertension Significant risk of bleeding (e.g. major trauma, peptic ulcer, recent brain/spine/ophthalmic surgery, recent intracranial haemorrhage) Spinal/epidural anaesthesia with treatment doses Thrombocytopenia
cautions for lmwh
Breastfeeding mothers (amount passed into breast milk and absorbed by the infant is thought to be negligible but manufacturers advise avoid) Concomitant drug treatments where an interaction may lead to a significantly increased risk of bleeding Hyperkalaemia Older adults Patients with low body weight Renal dysfunction Severe liver disease Severe renal impairment
what drugs should lmwh NOT be prescribed with
another anticoagulant (unless loading period for warfarin) LMWH should not be administered with NSAIDs, since this increases the risk of gastrointestinal bleeding. LMWH can increase potassium, therefore administration with a drug/drug class that also increases potassium could put the patient at risk of hyperkalaemia (e.g. ACE inhibitors). If prescribed together, urea and electrolytes should be monitored regularly.
what bl blood tests should you do before starting lmwh and why
Weight
FBC - platelets
U&E - renally excreted need baseline, can cause a hyperkalaemia
LFT - baseline, may need to switch if worsens
Anti-factor Xa - routine monitoring not required unless patient more high risk (eg renal failure, pregnancy)
what steps help reduce errors when prescribing lmwh’s
Know Weight and renal function.
- Weigh the patient at the start of therapy, and during treatment where applicable.
- Record the patient’s weight (in kg) accurately on the inpatient drug chart (when in use) and in the medical records.
- Calculate the treatment dose based on the patient’s weight (kg).
- Check the renal function and adjust doses accordingly.
how is weight taken in a pregnant patient starting lmwh
weight taken from early pregnancy as reference
for anticoagulants should you take the patients actual or ideal body weight
actual
what is the antedote to dabigatran
Idarucizumab
what is the antedote to apixaban
Andexanet alfa
what should you do if you ever see two doacs co-prescribed
take one off
should never be co-prescribed
when should the aptt ratio be checked after starting unfractioned heparin
4-6 hours
what is the mechanism of cerebral odema in dka
hyperosmolar state in dka promotes brain to produce osmolites to prevent dehydration (if didnt do this water would be pulled from intracellular space into intravascular space)
if give insulin and fluid correct at same time, the blood osmolality falls which means water is rapidly drawn into brain cells and odema can occur.
This is why fluids are given for 1 hour before insulin is given. So that the osmolarity of the blood can corrected slowly without fluid shift.
when should antiplatelets be stopped before surgery
1 week
which drugs interavt with G6PD deficience
Anti-malarials (e.g. primaquine and chloroquine)
Nitrofurantoin
Quinolone antimicrobials (e.g. ciprofloxacin)
Rasburicase
Sulphonamides (e.g. co-trimoxazole)
what antihypertensive should be cautioned with statins and why
statins are cp450 inhibitors
CCBs, amlodipine and diltiazem can accumulate and then cause a rhabdomyolisis
Statins should not be prescribed above 20mg in this group
symptoms of anaphylaxis
Itching Urticaria Hypotension Angioedema Wheeze
which antihypertensives can cause angioodema
ACE inhibitors
list some non allergic drug reactions
Morbilliform rash
Erythema multiforme
Fixed drug eruptions
Photosensitivity
what is a fixed drug eruption
Fixed drug eruptions are erythematous plaques that recur in the same place each time the causative drug is taken. Causes include paracetamol, tetracyclines and non-steroidal anti-inflammatory drugs (NSAIDs).
what is erythema multiforme
Erythema multiforme may arise secondary to infection or drugs such as penicillins, phenytoin and statins. It can rarely progress to Stevens-Johnson Syndrome and the potentially fatal Toxic Epidermal Necrolysis (TEN).
whats the difference between hives and erythema multiforme
hives move in hours
em fixed
which commonly prescribed drugs have histamine releasing properties
NSAIDS
analgesics
(so if someone gets urticaria or allergy prone may be likely to have reaction to these)
neuromuscular blockers
if someone is allergic to plasters what should happen with surgical management
not use latex gloves
if someone has a suspected allergy how should you give a drug
slowly
with steroids and antihistamines if needed
with anaphylaxis agents there if needed
how should mild-moderate and severe anaphylaxis be treated
mild-moderate - antihistamines (10mg) / steroids (200 mg)
severe - oxygen and im adrenaline (500 mcg)
why should IV adrenaline not be given in anaphylaxis
because it can cause life threatening arrhythmias
what should you do if you give im adrenaline and no response with anaphylaxis
repeat after 5mins
what should you do after someone has anaphylaxis
Prescribe prednisolone for up to 3 days.
Prescribe a non-sedating antihistamine for up to 3 days (adhere to your Trust formulary).
Issue or recommend a medical alert band if re-exposure is possible.
Ensure the allergy is documented in the medical notes and on the drug chart (electronic or paper-based system).
Communicate information to the general practitioner.
Warn the patient if the drug or related drugs are found in medicines available over-the-counter (e.g. salicylates/acetylsalicylates in patients who have reacted to an NSAID). Advise they check with a pharmacist prior to self-medicating with over-the-counter medicines.
Provide structured written information to the patient.
Prescribe two adrenaline auto-injectors for self-administration only when there is a significant risk of re-exposure.
Report the adverse drug reaction to the yellow card scheme.
how should you investigate analphyalxis
bloods - mast cell tryptase asap, second bloods at 2 hours (not longer than 4 hrs)
when assessing a ?analphylaxis what method should you use
how fast is it evolving - rapid/ slow/ static
systemic features - breathing, n&v, tachy, drowsy
how long should you observe someone with anaphylaxis
6-12 hours
where should all anaphylaxis be referred to
special allergy service
when is mast cell typtase useful
A mast cell tryptase level is of no help if the patient has had the cardinal signs and symptoms of an allergic reaction but is of use in suspected reactions during anaesthesia (e.g. to differentiate hypotension caused by allergy from that caused by direct action of drugs). In such cases, samples should be taken immediately after the patient has been stabilised, at 1-2 hours and 24 hours if possible.
what information should you give to a patient who has had an allergy
To avoid any known triggers for allergic reactions.
To avoid any cross-reacting drug classes where necessary.
How to use the adrenaline auto-injector if issued.
To purchase an alert bracelet or similar if necessary.
should you report anapylaxis via yellow card
yes - if resulted in shock or hospitalisation
how does carbamazepine effect the pill
makes it less effective
because its a cp450 inducer
what antiepileptic drug can cause thrombocytopenia
sodium valproate
list some general considerations when prescribing for patients with liver disease
Monitor LFTs, albumin, pro thrombin time and bilirubin at baseline and at regular intervals throughout treatment with drug treatments known to cause hepatotoxicity.
Monitor drug concentration where possible, to avoid toxicity which can cause liver injury.
Avoid drug-drug interactions which may increase the risk of liver injury.
Drugs that are dependent on the liver for metabolism are likely to need dose reduction.
Drugs that increase the risk of bleeding should be avoided, or used with caution in hepatic dysfunction.
Prescribe drugs that might exacerbate or precipitate the adverse effects of liver disease cautiously.
what medicines are contraindicated with COCP and POP
Enzyme inducers:
Rifampicin
Anti-epileptic drugs - carbamazepine, phenytoin
St johns wort
which anti epileptic drug is not an enzyme inducer
Lamotrigine
what factors affect whether a woman can be put on COCP
VTE risk (caution, 1RF, no 2RF) Arterial clot risk (HTN, CVD risk etc, caution 1 RF, no 2RF) Cancer - currently or in past 5 years Enzyme inducers Liver problems
which patients is the POP pill useful for
Those with VTE risk
what is an absolute contraindication to the COCP
Migraine with aura
what medicines can be used for emergency contraception
Levonorgesterel (if within 72 hours) Ella one (if within 5 days, but not if high BMI)
what do you need to prescribe if inserting a IUCD
Antibiotics - erythromycin
what are the drug names for common COCP and POP
COCP - ethinylestradiol + desogesterel / noresthisterone
POP - levogesterel
what drugs need to be cautioned/ stopped with macrolides
Any long QT drugs - eg AEDs (carbamazepine)
Warfarin
Statin (stop simvastatin, lower atorvastatin, can use fluvastatin)
CCB
Any drugs that prolong QT
Any drugs that cause low K
Theophylline
what is the name of vitamin K to reverse warfarin
phytomenadione
