[PWS] Difficult prescriptions Flashcards
How do you adjust insulin?
Total daily dose (TDD) = long acting + short acting
100/TDD = correction factor
The correction factor is how much 1U of insulin decreases blood glucose by
Then: (actual glucose - target glucose)/ correction factor
How do you change insulin if patient is sick?
You don’t
Continue normal insulin but with more monitoring
What do you do if patient is NBM to insulin?
Continue basal insulin
Omit bolus insulin
Give 3 examples of osmotic laxative
Lactulose
Movicol
Phosphate enema
How does an osmotic laxative work?
It draws water into stool > softens stool and stimulates peristalsis (increased bulk)
Containdication of osmotic laxatve
Bloating (may exacerbate it)
Phosphate enema: acute abdomen
Give 2 examples of stimulant laxatives
Senna
Bisacodyl
How do stimulant laxatives work?
Stimulate GI nerves > stimulate movement of bowel
Contraindications of stimulants
Examples of stimulants: senna, bisacodyl
Colitis
Cramps
Bowel obstruction
Colostomy
Which laxative is good for patients on opioids?
Stimulant laxative e.g. Senna
because they counteract the slowing down of gut movement caused by opioid
What anti-diarrhoeal meds can you give if NOT infective?
Loperamide 2mg PO - take after each loose movement
Alternative: codeine 30mg PO 6-hourly
What is the steroid ladder?
Help Carol Beat Medicine
Hydrocortisone
Clobetasone
Betamethasone
Mometasone
Very high potency = Clobetasol propionate (rarely used)
When do you need to wean a patient off steroids (rather than stopping abruptly)?
> 40mg pred for 1 week
3 weeks of treatment
repeated course
What situation is it okay to abruptly withdraw steroids?
If given for emergency (COPD/asthma)
What time of day should you take simvastatin?
in the evening (as cholesterol metabolism is predominantly in the evening and overnight)
Commonest side effect of statins
Muscle pains
When should you stop statins following LFT monitoring?
stop statins if AST/ALT >3 x ULN
continue statin otherwise
When must you stop statins in muscle myopathy?
if CK elevated (>5ULN) or severe muscular sx > STOP STATIN
resume at lower dose once CK has returned to normal
Why is warfarin + statins a concerning combination?
Because they will lead to a high INR
due to competitive inhibition of CYP by statin
Outline WHO pain ladder
- Non opioid (NSAID, paracetamol)
- Weak opioid
- Strong opioid
List some weak opioids (3)
Codeine
Tramadol
Morphine (oromorph PO, modiphied release morphine)
List some strong opioids (4)
Morphine
Diamorphine
Fentanyl
Oxycodone
How do you convert codeine / tramadol to oral morphine?
DIVIDE by 10
How do you convert oral morphine to subcut morphine?
DIVIDE by 2 (subcut is STRONGER than oral)
How do you convert oral morphone to oxycodone?
DIVIDE by 2 (oxycodone is stronger than morphine)
Which opioids can you give in CKD?
Oxycodone (GFR >30)
Fentanyl, alfentanyl, buprenorphinie (GFR<30)
How does warfarin work?
inhibits vit K epoxide reductase > reduces levels of 2, 7, 9 and10
What is INR target for AF, cardioversion, MI
2-3
What is INF target for mechanical heart valve
3-4
What does 1% mean in terms of mg in mL
10mg in 1mL
Remember: 1g in 100mL = 1000g in 100mL = 10mg in 1mL
How do you change / adapt COCP if surgery?
stop COCP 4 weeks beforee surgery
restart COCP 2 weeks post surgery
consider POP in interim
What kinds of laxatves are good for HAEMORRHOIDS?
Bulk forming laxative
Give examples of bulk formming laxative
Ispaghula hysk
Methylcellulose
When can biphosphonates be deprescrbed?
When taken for more than 10 years
as there is no evidence that they still work
What unit can you use for topical medications?
fingertip units (FTU)
Is aspirin technically an NSAID? What must you keep in mind?
Yes - it is technically an NSAID
but because it exists at a much lower dose, it is not necessarily subject to same level of caution
What is the only situation when cyclizine is contraindicated?
In HF (as it worsens fluid retention)
Give metoclopramide instead
What is the max dose of paracetamol daily?
4g a day
1g per dose, e.g. 4 times a day
How much paracetamol does one tablet cocodamol 30/500 contain?
500mg
Which drug type causes HYPOkalaemia?
THIAZIDE diuretic
Give an example of a thiazide diuretic
bendroflumethazide
Give an example of a thiazide-like diuretic
indapamie
How do thiazide diuretics work?
INHIBIT sodium and chloride resorption > low Na, Cl
Also: increase calcium reabsorption > high CA
How do thiazides cause hypoK?
Later in the nephron transporters attempt to resorb sodium
In doing this they excrete pootassium
Which diuretics cause hypokalaemia?
Loop + thiazide
what is the action of NSAIDs on the kidneys
cause renal artery constriction> reduce renal perfusion
What must you give for extrapyramidal sx e.g. dystonia?
procyclidine
What must you do if discontinuing statin due to muscle pains / raised CK?
Wait until muscle pains stop
then re start at lower dose
What is the first line anti-HTN in a 60yo Caucasian?
First line fluid for DKA
To restore circulating volume, the most appropriate initial management is a bolus of sodium chloride 0.9% via intravenous infusion, run over 10-15 minutes. Once this blood pressure is stabilised, fluids should be given at a rate that replaces the deficit and provides maintenance.
First line mucolytic in patients with cystic fibrosis
The BNF recommends dornase alfa as the first-choice mucolytic in patients with evidence of lung disease and a background of cystic fibrosis. This can be increased to twice a day in patients over 21 years old, if once daily isn’t effective. If there is an inadequate response, dornase alfa may be combined with hypertonic sodium chloride, or hypertonic sodium chloride alone should be considered.
Alternative correct answers include:
* Hypertonic sodium chloride
* Mannitol dry powder (used where dornase alfa is unsuitable secondary to ineligibility, intolerance, or inadequate response)
What to give for H.pylori eradication aside from antibiotics (clarithromycin and amoxicillin)?
This patient is presenting with peptic ulcer disease in the presence of H.pylori infection. H. pylori is a key risk factor in the development of peptic ulcers and if detected requires treatment with a ‘triple therapy’ regime that includes a PPI and two antibiotics for 7 days, and the continuation of full PPI therapy for 2 months in total. In patients who are not penicillin-allergic antibiotics will include amoxicillin 1g BD and either clarithromycin 500mg BD or metronidazole 400mg BD.
If the patient is penicillin-allergic, Clarithromycin 500mg PO BD and Metronidazole 400mg PO BD should be prescribed.
There is a range of PPIs that can be used in this situation, all of which would be considered correct:
Omeprazole 20-40mg BD for 7 days
Lansoprazole 30mg BD for 7 days
Esomeprazole 20mg BD for 7 days
Management of cranial diabetes inspidus
The BNF recommends the use of desmopressin or vasopressin for the treatment of cranial diabetes insipidus. Treatment may be required for a limited period only in diabetes insipidus following trauma or pituitary surgery.
Other alternative answers include:
Vasopressin 5-20 units every 4 hours (IM)
A low urine osmolality in conjunction with a high serum osmolality is strongly suggestive of what?
Diabetes insipidus
The water deprivation test is used to confirm diabetes insipidus and demonstrates a failure to concentrate the urine, on a background of dehydration. The desmopressin stimulation test is used to distinguish between cranial and nephrogenic diabetes insipidus, with cranial diabetes insipidus responding to desmopressin with a reduction in urine output and an increase in urine osmolality.
First line treatment for absence seizures?
Ethosuximide or valproate are prescribed first-line for absence seizures in children. The dose of ethosuximide is age-dependent. For example, for a child aged 6 – 17 years, the initial dose is 250 mg twice daily. The dose of valproate is age and weight-dependent. For example, for a child aged 1 month – 11 years, the initial dose is 10 – 15 mg/kg daily in 1 – 2 divided doses (max. per dose 600 mg).
Alternative answer(s):
Sodium valproate 200 – 300 mg PO daily in 1-2 divided doses
First line medication for type 2 diabetes control
The BNF recommends the following for the initiation of metformin immediate-release treatment:
Initially 500 mg once daily for at least 1 week, dose to be taken with breakfast, then 500 mg twice daily for at least 1 week, dose to be taken with breakfast and evening meal, then 500 mg 3 times a day, dose to be taken with breakfast, lunch and evening meal; maximum 2 g per day.
Modified release preparations can also be prescribed if patient’s struggle to tolerate the immediate release side effects.
First line therapy for acute mania (bipolar)
Antipsychotic drugs (such as haloperidol, olanzapine, quetiapine, and risperidone) are used in the treatment of acute episodes of mania or hypomania; if the response to antipsychotic drugs is inadequate, lithium or valproate may be added.
First line treatment for a cutaneous (non-facial) wart
The patient has a diagnosis of a cutaneous common wart, characterised by small skin-coloured lumps that feel firm and rough, commonly appearing on the palms, knuckles, knees and fingers.
Warts do not cause the patient harm, but some patients may find them itchy, painful or embarrassing.
The BNF recommends the use of salicylic acid for common warts, although warns not to apply the cream to large areas of skin or broken skin for risk of skin irritation. Cryotherapy is a commonly used alternative to medication.
Initial dose of first line SSRI for depression
The BNF recommends selective serotonin reuptake inhibitors (SSRIs), such as sertraline, for the management of moderate-to-severe depression as they are better tolerated by patients and safer in overdose. The starting dose of sertraline is 50mg once daily and this can be increased in steps of 50mg at intervals of at least 1 week, guided by patient responsiveness.
When should you stop potassium sparing diuretics before surgery?
On teh day
Why should metformin be stopped when patients are going fo rsurgery?
Patients will be ‘NBM’ before surgery, so metformin should be stopped as it can cause lactic acidosis
When prescribing a drug, what PMH of the patient should you consider?
peptic ulcer disease, chronic kidney disease, chronic heart failure, asthma, heart block, parkinson’s disease
How long should LMWH be given before starting long-term warfarin?
Until INR above 2
3 examples of LMWHs
Dalteparin
Enoxaparin
Tinzaparin
LMWH is needed to prevent the clot enlarging while the body breaks it down – treatment dose required
Which two medications should all patients with heart failure be on?
Beta blocks
ACE inhibitor
Add MRA (spironolactone) if symptoms continue
If eGFR is 30-45 consider lower doses of ACEI, ARBs, MRAs, sacubitril valsartan and digoxin.
Give two examples of SABAs
Salbutamol
Terbutaline
If AF onset is >48 hours or uncertain, is rate or rhythm control preferred?
RATE
Options for pharmacological cardioversion?
If no structural or ischaemic HD present = flecainide acetate
Otherwise = amiodarone
Example of insulin prescription for hyperkalaemia
NovoRapid
10 units in 50mL glucose 50% given over 5-15 minutes
First line for focal seizures
Lamotrigine or levetiracetam
Which class of diabetes drugs is most associated with hypoglycaemia?
Sulfonylureas, such as gliclazide, glimepiride, glipizide, and tolbutamide.
It is more likely with long-acting sulfonylureas such as glimepiride, which have been associated with severe, prolonged and sometimes fatal cases of hypoglycaemia. Sulfonylureas are also associated with modest weight gain, probably due to increased plasma-insulin concentrations.
Which anti-diabetic drug may be useful in obese patient with cardiovascular disease?
Sodium glucose co-transporter 2 (SGLT2) inhibitors, such as canagliflozin, dapagliflozin, empagliflozin, and ertugliflozin, in addition to lowering blood-glucose, may promote weight loss and improve cardiovascular outcomes in certain patients.
There is greater uncertainty around the cardiovascular benefits associated with ertugliflozin than there is for canagliflozin, dapagliflozin, and empagliflozin.
SGLT2 inhibitors are associated with a risk of diabetic ketoacidosis.
Which drugs should not be prescribed when renal function is impaired?
loop diuretics (e.g. furosemide), potassium-sparing diuretics (e.g. spironolactone), aminoglycoside antibiotics (e.g. gentamicin), NSAIDs(e.g. ibuprofen), angiotensin converting enzyme (ACE) inhibitors (e.g. ramipril), digoxin, lithium, other antibiotics (e.g. ciprofloxacin, cephalosporins, methotrexate, opioid analgesics (e.g. morphine) metformin, sulfonylureas (e.g. gliclazide) and insulin.
Which drugs should be avoided in impaired liver function?
benzodiazepines (e.g. diazepam), metformin, NSAIDs (e.g. ibuprofen), statins (e.g. atorvastatin) and warfarin.
Poor LVF on echocardiogram might contra-indicate which drugs?
NSAIDs, metformin, thiazolidinediones, Class I antiarrhythmics and calcium channel blockers.
When diarrhoea is a prominent symptom in irritable bowel syndrome, what should be prescribed?
loperamide hydrochloride 2 mg PO as required
In IBS with discomfort relating to spasm, what should be prescribed?
mebeverine hydrochloride m/r 200 mg PO twice daily
This should be taken as required alongside dietary and lifestyle advice
Which laxatives should/should not be given in IBS?
A bulk-forming laxative (e.g. ispaghula husk given in water after food) is ideal. Lactulose should be avoided as it may cause bloating.
What are the two options for STEP 4 management of hypertension?
(i) low-dose spironolactone (25 mg PO daily) if the blood potassium level is ≤4.5 mmol/L, and (ii) if blood potassium level is >4.5 mmol/L, an alpha-blocker or beta-blocker
NOTE: alpha blockers (e.g. doxazosin) may also help with prostate symptoms in male patients
If a patient has refused surgical management of PVD, what can be prescribed?
naftidrofuryl oxalate 100mg PO TDS
Pharmacological therapies suitable for prevention of migraines
propranolol, topiramate and amitriptyline, which should be started at low doses and titrated according to symptoms.
It should be noted that topiramate is contraindicated in pregnancy.
Propranolol 80-240mg PO once daily in divided doses (e.g. 40mg BD)
Topiramate 25mg PO once daily for 1 week (then increased in steps of 25mg every week)
Amitriptyline 10-25mg PO in the evening (if tolerated, increase in steps of 10-25mg every 3-7 days in 1-2 divided doses to a usual dose of 25-75mg daily)
Carbimazole dosing for Graves?
15–40 mg daily continue until the patient becomes euthyroid, usually after 4 to 8 weeks, higher doses should be prescribed under specialist supervision only, then reduced to 5–15 mg daily, reduce dose gradually, therapy usually given for 12 to 18 months.
The alternative answer would be propylthiouracil (PTU), and the dose would be as follows:
Initially 200–400 mg daily in divided doses until the patient becomes euthyroid, then reduced to 50–150 mg daily in divided doses, initial dose should be gradually reduced to the maintenance dose.
PTU is usually used when carbimazole is not tolerated, the patient is trying to conceive or is pregnant, or has a history of pancreatitis; there is no relevant PMH/FH, and the patient is taking hormonal contraception.
Treatment for bacterial vaginosis?
typically presents with discharge, pruritus, and dyspareunia
oral metronidazole 400-500mg twice daily
Treatment of cellulitis if penicillin allergic?
Clarithromycin 500 mg twice daily for 5–7 days (if not pregnant)
Erythromycin 500mg PO QDS for 5-7 days (if pregnant)
If NOT pen allergic: The BNF recommended flucloxacillin 0.5–1 g QDS for 5–7 days as the first-line antibiotic for cellulitis.
Treatment options for prolactinoma?
Bromocriptine 1mg ON, increasing gradually to 5mg every 6 hours.
Cabergoline 500micrograms oral once weekly
What is the initial empirical therapy of choice for meningitis?
cefotaxime
can be administered by intramuscular injection, intravenous injection, or intravenous infusion. The dose is 50mg/kg (50mg x 30kg weight = 1500g or 1.5g) every 6-8 hours,
Dose of adrenaline for adult with anaphylaxis?
500 micrograms of 1:1000 solution
What does the BNF recommend for the management of mild-moderate acne?
Fixed combination topical adapalene (0.1%) with benzoyl peroxide (2.5%)
Fixed combination topical benzoyl peroxide with clindamycin
Fixed combination topical tretinoin with clindamycin
All of the above should be prescribed to be used once daily (at night).
What are the first-line antipyretics in children?
First-line antipyretic drugs in children include paracetamol and ibuprofen. Paracetamol is indicated for pyrexia alone, whereas ibuprofen is typically recommended when pyrexia is associated with discomfort.
Management of epiglottitis?
Cefotaxime
Child with high fever, sore throat, inability to control secretions and difficulty breathing (audible stridor)
Likely epiglottitis
typically occurs in children aged 2-6 years. The most common causative organism is Haemophilus influenzae.
What should be given in suspected meningitis (GP setting) if penicillin allergic?
Cefotaxime
First line to prevent pneumococcal infection in patients with sickle-cell?
Phenoxymethylpenicillin 125mg PO BD
https://www.medicinescomplete.com/#/content/bnfc/_685757008?hspl=phenoxymethylpenicillin
Erythromycin is used second line in children who are penicillin allergic.
Treatment of localised, non-bullous impetigo?
hydrogen peroxide 1% cream (Crystacide) 2-3 times a day for 5-7 days
Topical antibiotics such as mupirocin, fusidic acid, retapamulin, and ozenoxacin should be used if hydrogen peroxide cream is unsuitable (e.g., if impetigo is around eyes) or ineffective.
