Commonly prescribed drugs in hospital

Please note this information is for educational purposes only and prescriptions should not be based on this. OSCEstop takes no responsibility for use of this information.


You must know these:

  • Cardiac arrest: DC shock 150J biphasic, adrenaline 1mg IV (10ml of 1 in 10,000), amiodarone 300mg IV (if shockable rhythm)
  • Anaphylaxis: adrenaline 0.5mg IM (0.5ml of 1 in 1000)
  • Seizure: lorazepam 4mg IV (or if no IV access, diazepam 10mg PR)
  • Hypoglycaemia: 10% glucose 200ml IV or 20% glucose 100ml IV (repeat as needed), or glucagon 1mg IM (if no IV access)
  • Hyperkalaemia: calcium gluconate: 30ml 10% IV over 15 minutes THEN actrapid insulin 10 units in 125ml 20% dextrose IV over 30 minutes + salbutamol 10mg neb
  • Bradycardia: atropine 500mcg IV (repeat every 3-5 minutes to maximum of 3mg if needed)
  • SVT: adenosine 6mg IV (can be followed by 12mg then 18mg if unsuccessful)
    • NB: must be given as a bolus and flushed quickly via a large vein.
  • Pulsed VT (without life threatening features): amiodarone 300mg IV over 10-60 minutes followed by 900mg over 24 hours through a large vein (900mg should be via central venous line)
  • Rapid tranquillisation of agitated patient at risk of self harm to self / others: lorazepam 1-2mg PO/IM or olanzapine 5-10mg PO/IM
    • Tranquilisation notes: use oral where possible; give half dose in elderly or renal impairment


Analgesic ladder

  1. Non-opioid (paracetamol or NSAID)
  2. Weak opioid (e.g. codeine) ± non-opioid
  3. Strong opioid (e.g. morphine) ± non-opioid
  • Paracetamol 1 gram PO/IV, PRN 4-6 hourly (max. 4 grams), or QDS
  • Ibuprofen 400mg PO, QDS (contraindicated if gastritis history)
  • Co-codamol 8/500 or 30/500 2 tablets PO, PRN 4-6 hourly (max. 8 tablets), or QDS
  • Codeine 30-60mg PO, PRN 6 hourly (max. 240mg), or QDS (if regular
  • Tramadol 50100mg PO, PRN 4-6 hourly (max. 400mg), or QDS 
  • Morphine sulphate oral solution (Oramorph) 10mg/5ml 5-10ml PO, PRN 2 hourly (reduce dosing interval or use alternative in renal impairment)
  • Morphine 1-10mg IV/IM/SC, PRN 4 hourly (max. 60mg; reduce dosing interval or use alternative in renal impairment)
    • As a rough guide, the IV dose of morphine is 0.1mg/kg. So for a 70kg person, the dose would be 7mg. If given in a non-monitored environment (theatres / intensive care / resus) this should be given with caution.
  • Morphine sulphate modified release tablets (Zomorph/MST) 10-60mg PO, 12-hourly 
  • Morphine PCA (patient-controlled analgesia) 1mg bolus, 5 minute lockout (button only to be pressed by patient)
Opioid conversions
  • IV morphine = 3 x stronger than oral morphine
  • Subcutaneous morphine = 2 x stronger than oral morphine
  • Oxycodone = 2 x stronger than morphine (if same administration route)
  • Fentanyl patch: 24 hour oral morphine dose (in mg) ÷ 3 = fentanyl patch dose in mcg/hour (safe in renal impairment)
  • Buprenorphine patch: 24 hour oral morphine dose (in mg) ÷ 2.3 = buprenorphine patch dose in mcg/hour
  • Subcutaneous alfentanyl = 30 x stronger than oral morphine (safe in renal impairment)
Concept of background and breakthrough analgesia

For patients with ongoing severe pain, you should prescribe regular background (long-acting) analgesia with PRN breakthrough (short-acting) analgesia. The initial dose of background analgesia should be equivalent to the average dose of PRN analgesia they are currently needing over 24 hours. Breakthrough analgesia should be about 1/6 the dose of the total background analgesia dose. Prescribe this 4-hourly PRN. For example, if a patient has been needing 60mg Oramorph a day, convert them to 30mg MST BD, and also prescribe 10mg Oramorph PRN 4-hourly for breakthrough pain.

Subcutaneous PRN medications in palliative patients (all PRN 1-2 hourly)
  • Morphine 2.5mg (max. 20mg/24 hours) – for pain/SOB (use alternative in renal impairment, e.g. fentanyl/oxycodone)
  • Midazolam 2.5mg (max. 20mg/24 hours) – for anxiety and agitation (reduce dose in renal impairment)
  • Hyoscine butylbromide 20mg (max. 120mg/24 hours) – for bronchial secretions
  • Haloperidol 0.5-1.5mg (max. 5mg/24 hours) – for nausea and vomiting 
Subcutaneous syringe driver in palliative patient (all over 24 hours)

Tailor to patient’s symptoms – content options include:

  • Morphine 10-20mg – for pain and breathlessness (use alternative in renal impairment, e.g. fentanyl/oxycodone)
  • Midazolam 10-20mg – for confusion without hallucinations (reduce dose in renal impairment)
  • Hyoscine butylbromide 40-120mg – for bronchial secretions
  • Haloperidol 2.5-5mg – for nausea and vomiting; or confusion with hallucinations
  • Cyclizine 75-150mg – for nausea and vomiting
  • Levomepromazine 5-25mg – for nausea and vomiting (2nd line)

Nutritional supplements

  • Fortisip Compact Extra 125ml PO, BD/TDS/QDS
  • Sanatogen A-Z Complete tablets 1 tablet PO, OD
  • Thiamine 100mg PO, BD
  • Vitamin B Compound Strong 2 tablets PO, BD


  • Senna 7.5-15mg PO, ON (stimulant laxative – first line for acute and opiate constipation)
  • Macrogol oral powder (Movicol) 1-2 sachets PO, OD/BD/TDS (osmotic laxative – for faecal impaction)
  • Ispaghula husk (Fybogel) 1 sachet PO, BD (bulk forming laxative – first line for chronic constipation, elderly patients and pregnant patients)
  • Magnesium hydroxide 30-45ml PO, ON (osmotic laxative – often used for post-operative patients)
  • Glycerol 4g suppository 1 suppository PR, STAT (stimulant laxative)
  • Phosphate enema 1 enema PR, STAT (osmotic laxative)


  • Cyclizine 50mg IV/IM/PO, PRN 6-8 hourly (max. 150mg)
  • Ondansetron 4mg IV/IM/PO, PRN 4-6 hourly (max. 16mg) – can cause QT prolongation
  • Metoclopramide 10mg IV/PO TDS (antidopaminergic SEs, so give for maximum of 5 days and avoid if young/Parkinson’s/dyskinesias)

Sleeping tablets

  • Zopiclone 7.5mg PO (3.75mg if elderly), ON (caution in renal impairment)
  • Temazepam 10mg PO, ON (caution in renal impairment)


  • Salbutamol 2.5-5mg NEB, PRN 4-6 hourly (max. 20mg) – can be given more frequently if required 
  • Ipratropium bromide 250-500micrograms NEB, PRN 4-6 hourly (max. 2mg)
  • Prednisolone 30-40mg PO, OD

Correcting electrolytes

  • Mild (>2.5mmol/L): Sando-K 2 tablets TDS x 3/7, or add 20-40mmol/L potassium chloride to each litre of IV fluids
  • Severe (<2.5mmol/L or ECG changes): 40mmol/L potassium chloride in 1L 0.9% saline over 4-6 hours (NEVER >10mmol/hour K+ outside ICU)
  1. ECG and cardiac monitoring
  2. Calcium gluconate 10ml 10% IV over 15 minutes if ECG changes (consider if severe, i.e. ≥6.5mmol/L, without ECG changes)
  3. Actrapid insulin 10 units in 125ml 20% glucose IV over 30 minutes + 10mg salbutamol neb
  4. Sodium zirconium cyclosilicate 10g PO TDS for up to 72 hours 
  1. Mild (>1.9mmol/L and asymptomatic): calcium (e.g. Sandocal or Calcichew) 1000mg BD + vitamin D if deficient 
  2. Severe (<1.9mmol/L or symptomatic): calcium gluconate 10ml 10% IV over 10 minutes – can be repeated until asymptomatic and usually needs to be followed by an infusion (50ml 10% calcium gluconate in 500ml 0.9% saline over 12 hours)
  • Replace fluid deficit with 0.9% saline and keep patient well hydrated (continuous IV fluids)
  • Severe (>3.5mmol/L or symptomatic): if calcium stops falling with IV fluids alone, consider IV bisphosphonate, e.g. zoledronic acid 4mg IV, depending on renal function (one-off dose)
  • PO: magnesium aspartate 1 sachet (10mmol) BD x 3/7
  • IV: 5grams (20mmol) magnesium sulphate in 500ml 0.9% saline over 5 hours
  • PO: Phosphate-Sandoz 2 tablets TDS x 3/7
  • IV: Phosphate Polyfusor (50mmol in 500ml) 100-300ml over 12-24 hours depending on weight and severity OR sodium glycerophosphate 10mmol in 500ml 0.9% saline over 12 hours – must give through different cannula to other electrolytes if co-administering

Test your knowledge with a scenario…

A 34 year old homeless patient who drinks alcohol to excess presents with a withdrawal seizure after stopping drinking because he ran out of money to buy alcohol.

How would you manage an actively seizing patient?

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After the seizure resolves, would you give any medications to prevent further seizures?

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Which additional vitamins/supplements would you consider prescribing?

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The patient has also been started on Fortisips nutritional supplements due to their low body mass index. Two days later, the patient’s electrolytes are checked and reveal Sodium 142 mmol/L; Potassium 2.6 mmol/L; Magnesium 0.4 mmol/L; Phosphate 0.4 mmol/L; Calcium 2.5 mmol/L. What is going on?

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What replacement would you prescribe?

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Try some OSCE stations

  1. Hyperkalaemia
  2. Asthma exacerbation
  3. Status Epilepticus
  4. End of life medication prescribing
  5. Asthma exacerbation prescribing
  6. COPD exacerbation prescribing
  7. Medication review
  8. There’s even more here!

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