Chapter 2: Prescription Review Flashcards
Safe routine for Pescribing
PReSCRIBER
- Patient details
- Reactions (+allergies)
- Sign, front of chart
- Contrainidcations
- Route
- IV fluids
- Blood clot prophylaxis
- (anti)Emetic
- Relief of pain
What to check for P in PReSCRIBER
Patient details
3 pieces of information needed: name + DOB + Hosp #
What to check for Re in PReSCRIBER
Reactions i.e. allergy + the reaction.
Complete or check allergy box before prescribing.
NB: Co-amoxiclav + Tazocin both contain penicillin.
What to check for S in PReSCRIBER
Sign : Front of chart + individual pescription
What to check for C in PReSCRIBER
Contraindications:
BANS: consider 4 groups of drugs.
- Bleeding risk:
- Do not give if patient bleeding or suspected or at risk of bleeding e.g. prolonged PT in CLD.
- Prophylactic heparin CI in acute ischaemic stroke as may bleed into stroke.
- Enzyme inhibitors (AO DEVICES) can increase warfarin’s effect, despite stable dose e.g Erythromycin
- Antihypertensives:
- Hypotension – including postural hypotension, from ALL groups of antihypertensives.
- Bradycardia – B-blockers + CCBs.
- Electrolyte disturbances – ACE-i + diuretics.
- Specific side-effects: ACE-i = dry cough; B-blockers = wheeze in asthmatics + worsening of ACUTE heart failure; CCBs = peripheral oedema + flushing; diuretics = renal failure → loop diuretics = gout, K+-sparing diuretics (e.g. spironolactone) = gynaecomastia.
- NSAIDs:
- Cautions/CIs = NSAID = No urine (renal failure), Systolic dysfunction (HF), Asthma, Indigestion (any cause) + Dyscrasias (clotting abnormality).
- NB: Although aspirin an NSAID, it is NOT CI in renal or HF, or asthma.
- Steroids:
- S/Es (+ loosely the Cis) = STEROIDS = stomach ulcers, thin skin, edema, R+L HF, osteoporosis, infection, diabetes (mainly hyperglycaemia, rarely progresses to diabetes), syndrome (Cushing’s).
Contraindications: B
Bleeding risk:
- Do not give if patient bleeding or suspected or at risk of bleeding e.g. prolonged PT in CLD.
- Prophylactic heparin CI in acute ischaemic stroke as may bleed into stroke.
- Enzyme inhibitors (AO DEVICES) can increase warfarin’s effect, despite stable dose.
Contraindications: A
Antihypertensives:
- Hypotension – including postural hypotension, from ALL groups of antihypertensives.
- Bradycardia – B-blockers + CCBs.
- Electrolyte disturbances – ACE-i + diuretics.
- Specific side-effects:
- ACE-i = dry cough;
- B-blockers = wheeze in asthmatics + worsening of ACUTE heart failure;
- CCBs = peripheral oedema + flushing;
- Diuretics = renal failure + loop diuretics = gout, K+-sparing diuretics (e.g. spironolactone) = gynaecomastia
Contraindications: N
NSAIDs:
- Cautions/CIs = NSAID = No urine (renal failure), Systolic dysfunction (HF), Asthma, Indigestion (any cause) + Dyscrasias (clotting abnormality).
- NB: Although aspirin an NSAID, it is NOT CI in renal or HF, or asthma.
Contraindications: S
Steroids: S/Es (+ loosely the Cis) = STEROIDS
- stomach ulcers
- thin skin
- edema
- R+L HF
- osteoporosis
- infection
- diabetes (mainly hyperglycaemia, rarely progresses to diabetes)
- syndrome (Cushing’s)
What to check for R in PReSCRIBER
Route for each drug.
- Vomiting = give via IV/IM/SC.
- If short-lasting vomiting (which it usually is) = no need to change route of other prescribed medicines.
- Doses of anti-emetics all SAME regardless of route e.g. cyclizine 50mg 8-hourly, metoclopramide 10mg 8-hourly.
- NBM still need their oral medication, including prior to surgery.
What to check for I in PReSCRIBER
IV fluids.
Prescribed in 2 situations: (1) Replacement = if dehydrated/acutely unwell; (2) Maintenance = if NBM.
What to check in replacement fluids?
Replacement: Which fluid? All 0.9% saline unless:
- Hypernatraemic or hypoglycaemia = give 5% dextrose.
- Ascites = give human-albumin solution (HAS) – maintains oncotic pressure, 0.9% saline worsens ascites.
- Shocked with SBP < 90mmHg = 500 ml 0.9% Sodium Chloride over 15 minutes (250 ml in elderly). (x3->inotropes)
- Shocked with bleeding = 500 ml 0.9% Sodium Chloride over 15 minutes (250 ml in elderly), then like with like (senior decision)
Replacement: How much + how fast? Assess HR, BP + UO first.
- Tachycardic + hypotensive = 500ml IV STAT (250ml if HF) → reassess.
- Only oliguric (not obstruction) = 1L over 2-4h → reassess.
- ↓UO (oliguric <30mL/h, anuric <0ml/h) = 500ml depleted.
- ↓UO + tachycardia = 1L depleted.
- ↓UO + tachycardia + hypotension (i.e. shocked) = >2L depleted.
- General rule – never prescribe >2L IV fluid, as should review rate regularly.
- 0.9% saline 1L 2⁰ = give over 2h – should write “2 hours” or “2-hourly” instead.
What to check in maintenance fluids?
Which fluids + how much?
- Adults need 3L/day of IV fluid OR 25-30ML/KG/DAY. Elderly need 2L/day.
- Adequate electrolytes = 1 salty + 2 sweet = 1L 0.9% saline + 2L 5% dextrose.
- Provide K+ by adding KCl to bags, guided by U&Es. If N K+, need 1mmol of KCl/kg/day. (c.40mmol/day)
- Do NOT give IV K+ at rate of >10mmol/hour.
How fast?
- If giving 3L/day = 8 hourly bags.
- If giving 2L/day = 12 hourly bags.
- Before prescribing, always check: U&Es, not fluid overloaded, bladder not palpable.
What to check for B in PReSCRIBER
Blood clot prophylaxis.
- To prevent VTE, majority get LMWH (e.g. dalteparin 5000U daily SC) + compression stockings.
- Drug charts provide assessment tool.
- Note if bleeding/suspected/at risk (including ischaemic stroke), don’t give warfarin or heparin.
- If peripheral arterial disease, don’t give compression stockings (may cause acute limb ischaemia)
What to check for E in PReSCRIBER
Emesis relief.
- Nauseated = regular anti-emetic vs Not nauseated = as-required anti-emetic:
- Cyclizine 50mg 8-hourly IM/IV/oral → but fluid retention
- Metoclopramide 10mg 8-hourly IM/IV if HF.
- Avoid cyclizine (anti-histamine) if HF, otherwise good 1st-line for almost all cases except cardiac [as can cause fluid retention]
- Avoid metocloporamide (dopamine antagonist) if Parkinson’s disease (exacerbates) + young women (dyskinesia, especially acute dystonia).
Cyclizine = histamine H1 receptor antagonist
What to check for R in PReSCRIBER
Relief of Pain
- No pain = nil regular & PRN paracetamol 1g up to 6-hourly oral.
- Mild pain = paracetamol 1g 6-hourly oral & PRN codeine 30mg up to 6-hourly oral (or tramadol).
- Severe pain = co-codamol 30/500 2 tablets 6-hourly oral & PRN morphine sulphate 10mg up to 6-hourly oral.
- co-codamol 30/500 = codeine 30mg+Paracetamol 500mg
- In order of increasing effectiveness, morphine sulphate may be given orally (oramorph), SC or IV.
- Oramorph comes in 2 strengths (more concentrated rarely used) – so must specify, usually 10mg/5ml.
- NSAIDs can be introduced at any stage (e.g. ibuprofen 400mg 8-hourly) regularly or ‘as required’ if no CI.
- Neuropathic pain (arises from nerve damage or disease, usually shooting/stabbing/burning): amitriptyline 10mg oral night (1st line) → pregabalin 75mg oral 12-hourly.
- Duloxetine 60mg oral nightly given if diabetic neuropathy.
- Check paracetamol + co-codamol e.g. 2 co-codamol 30/500 6-hourly = 500 x 2 x 4 = 4000mg = 4g = maximum paracetamol level reached. Stop either of the drugs (paracetamol or co-codamol), dictated by patient’s pain.
Dangerous SE clozapine
Agranulocytosis resulting in neutropenia
Must stop and refer to haemotologist
what is microgynon?
& when CI?
COCP
in migraine with aura
How do NSAIDs & oral steroids contribute to indigestion?
- ibuprofen inhibits prostaglandin synthesis needed for gastric mucosal protection from acid. inflammation & ulceration
- oral steroids inhibit gastric epithelial renewal thus –> predisposing to ulceration
-
what class of drug are metoclopramide and domperidone? how do they differ
Dopamine anti-emetics (both are dopamine antagonists)
Metaclopramide crosses the BBB, so exacerbates P symptoms by acting on central dopamine receptors
Domperidone doesn’t cross BBB so is safer to use in PD
What can all diuretics do to sodium? when cause they cuase the opposite?
[in terms of sodium conc]
hyponatraemia
when they contribute to dehydration they can also cause hypernatraemia
