Introduction to BNF and Prescribing

1. Introduction to BNF and Prescribing ICL – 3rd year medical students

2. Aim To be able to navigate around the BNF Objectives Summarise the information contained within each of the sections within the BNF Demonstrate ability to retrieve information from the BNF Prescribe at least one drug on the Manchester Prescription Chart

3. Summarising BNF information Work with the person sitting next to you Activity 1 Summarise the information in pages 0-42 (or ‘Preliminary’) Activity 2 Describe the information available in section 2 on ‘supraventricular & ventricular arrhythmias’ Also the information under ‘amiodarone’

4. Summarising BNF information Work with the person sitting next to you Activity 3 Summarise the information contained in appendix 1 (‘appendices’). Identify if there is an interaction between amiodarone & simvastatin by looking up both drugs PLUS Activity 4 Summarise the information in appendices 2-5. Tell the group important information about infusing amiodarone

5. BNF Sections Part 1 Lots of useful information about prescribing and prescribing in certain conditions e.g. palliative care Part 2 Section 1-15 Individual drug monographs Appendix Appendix 1 - Interactions Appendix 2 - IV additives Appendix 3 - Borderline substances Appendix 4 - Wound management products & elasticated garments Appendix 5 - Cautionary &advisory labels Additional Information (back of BNF)

6. Completing thePrescription Patient details, NHS number important as may have more than one patient of same name Ward and consultant Allergies Chart details Drug by APPROVED name (unless an exception) Dose, use most approp. Format e.g. 0.5mg write as 500 micrograms (not mcg) Route and review/stop date Never abbreviate ‘units’ to ‘u’ 1 1 1112223335 Bloggs Joseph 25.4.65 75Kg Dr Shields MAU 22/9/10 NKDA AMOXICILLIN 500mg IV 22/9 DO 24/9 D Octor TF S CAP 7/7 23/9/10 Nasal 24% 2L/min COPD DO D Octor 5555

7. Indicate the frequency by ticking the times Always indicate a frequency on PRNs Don’t forget to indicate if controlled release Only use Latin abbreviations listed in BNF (avoid q.q.h. as often confused with q.d.s.) Always state a maximum in 24 hours Completing thePrescription Bloggs Joe 1112223335 25.4.65 PARACETAMOL 1g PO 23/9 DO 28/9 D Octor TF S M/R or X/L ISOSORBIDE Mononitrate 60mg PO 23/9 DO n/a D Octor TF 23/9 Angina DIHYDROCODEINE TFS 30mg PO A Doc 29/3 Dr Doc PAIN 3 hourly 240mg

8. Prescribing PracticeCase 1 One of the nurses asks you, in passing, to prescribe some ‘PRN paracetamol’ for Amy. She is not on regular medications and has no allergies (the reason for admission is not a contraindication to paracetamol being prescribed) Miss Amy Patient, DOB 12/7/72, NHS No. 2819735, Ward MAU, Consultant Sharma

9. Case 1 continued The patient has some tests done and a diagnosis of community-acquired pneumonia is made Your registrar asks you to prescribe ‘oral Augmentin’ What further information would you need? What information sources would you use?

10. Don’t forget patient details at top of each page used PARACETAMOL TFS 1g oral 4-6hrly D Octor 28/9 4g D Octor Pain

11. CO-AMOXICLAV 500/125   1 tablet oral 22/9 D Octor 25/9 D Octor TFS  COMMUNITY ACQUIRED PNEUMONIA 7 days

12. Summary You will have the opportunity to utilise these skills over the next 3 years. .

13. BNF Questions 1. Your patient is taking warfarin. Is it safe to start carbamazepine to treat this patient's poorly controlled epilepsy? 2. You have been asked to provide palliative care treatment for a patient with cancer. You need to increase the dose of the patient's morphine modified-release tablets to 120mg every 12 hours. What would be a suitable 4 hourly breakthrough dose of morphine sulphate oral solution? 3. A patient has deteriorating renal function, as indicated by his eGFR which is 17ml/minute/1.73m2. What dose of Tazocin should he be prescribed?

14. 4. A doctor wishes to start a patient with liver impairment on an antidepressant. Is Cipralex safe to use? 5. The internet is not working so you cannot access Toxbase. Do you need to prescribe anything for a patient who took a paracetamol overdose 9 hours ago and has a level of 60mg/L? They are not taking any other medications and are generally healthy.

15. Answers 1.Your patient is taking warfarin. Is it safe to start carbamazepine to treat this patient's poorly controlled epilepsy? Appendix 1 - Interactions Metabolism of coumarins accelerated by carbamazepine therefore INR can be reduced. 2.You have been asked to provide palliative care treatment for a patient with cancer. You need to increase the dose of the patient's morphine modified-release tablets to 120mg every 12 hours. What would be a suitable 4 hourly breakthrough dose of morphine sulphate oral solution? Prescribing in Palliative Care- under subheading ‘Pain management with opioids’ Breakthrough pain is one-tenth to one-sixth of 24 hour total daily dose every 2-4 hours when required. Total daily dose for this patient is 120mg x 2 = 240mg. Therefore breakthrough dose is 24mg-40mg depending on clinical assessment of need. 3.A patient has deteriorating renal function, as indicated by his eGFR which is 17ml/minute/1.73m2. What dose of Tazocin should he be prescribed? Piperacillin with tazobactam monograph – under subheading ‘Renal Impairment Maximum dose = 4.5g every 12 hours.

16. Answers 4.A doctor wishes to start a patient with liver impairment on an antidepressant. Is Cipralex safe to use? Escitalopram monograph – under subheading ‘Hepatic Impairment’ Initial dose of 5mg daily for two weeks increasing thereafter to 10mg daily according to response and LFTs. Particular care should be taken in severe impairment. 5. The internet is not working so you cannot access Toxbase. Do you need to prescribe anything for a patient who took a paracetamol overdose 9 hours ago and has a level of 60mg/L? They are not taking any other medications and are generally healthy. Emergency treatment of poisoning section – under subheading ‘Analgesics – Paracetamol’ Using the graph – treatment is not necessary as serum level is below the treatment line.