Clinical Pharmacology Notes PDF

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Lecture notes from an introductory lecture on clinical pharmacology...

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Clinical Pharmacology, Therapeutic and Prescribing Medicine Reconciliation Medicines reconciliation is a process designed to ensure that all medication a patient is currently taking is correctly documented on admission and at each transfer of care It is carried out at 3 stages in hospital: 1. Admission 2. Post admission verification (by pharmacy team) 3. Discharge

Steps to take: 1. Collecting information on the drug history using the most recent and accurate sources of information. 2. Checking or verifying that list against the initial inpatient prescription, ensuring any discrepancies are accounted for and are appropriately followed up. 3. Communicating the drug history together with action taken on any changes, omissions and discrepancies through appropriate documentation. Sources of information: • Patient (Adv. = can tell you exactly how meds are taken. Disadv. = patient may be confused, unable to communicate) • Patient’s own drugs (PODs) (Adv. = can check dates, have exact med. Disadv. = may be left at home, may be old or illegible. Some patients don’t count eyedrops, insulin or inhalers as meds.) • Summary Care Records (SCR) (are an electronic record containing key info from patients GP practise. As a minimum they contain allergies, adverse reactions medications. Need patient permission unless patient is confused or unconscious) • Carer or Nursing/Residential Home (be mindful about confidentiality) (nursing homes have MAR sheets – Medication Administration Record) • GP Surgery; phone call/ medication record/ referral letters (be aware of acute medicines, repeat medicines and past medicines on receptionist’s screen)

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Previous eTTA (discharge summary) (check whether any changes have been made by GP since discharge) Community Pharmacy (can find contact info. for here if Dosette box is used) Prescription from another hospital Repeat prescription list (always check last date of issue. Renal patients on dialysis take drugs not supplied by GP)

Avoiding errors BNF (British National Formulary): • Drug monographs: include dosing info. and details indications of use for each drug (licensed and unlicensed) Formulation: • Some drugs have different doses depending on the formulation used, due to differing bioavailability • E.g. carbamazepine suppositories: different bioavailability to the tablets of suspension. 125mg may be equivalent to 100mg tablets • Modified release: if a medicine needs to be given 2-3 times daily, there will be a modified release preparation available to allow less frequent dosing • E.g. immediate release preparation of nifedipine requires 3 times daily dosing. Adalat LA is formulated as slow release, and can be given once daily • Morphine can be given as Oramorph every 4 hours for breakthrough pain in palliative care Drug interactions: Pharmacodynamic: occur when 2 drugs have additive or antagonistic pharmacological effects. Pharmacokinetic: occur when a drug increases or decreases the amount of another drug available in the body by affecting the absorption, distribution, metabolism or excretion of the other drug. Appendix 1 – the BNF lists a number of drug interactions. Those marked by a black dot ● are considered to be the most serious. www.medicines.org.uk/emc --> Any licensed med will have a data sheet here Legal prescribing: For a prescription to be valid it needs to be: – Signed in ink with your own name – Written in indelible ink i.e. permanent – Contain • Address of practitioner • Appropriate date The signatory takes legal responsibility for the prescription (department of health advice) Prescribing error = “The result of a prescribing decision or prescribing writing process that results in an unintentional but significant reduction in the probability of treatment being timely and effective or an increased risk of harm compared with generally accepted practice” 2 main types of error: 1. Slips and lapses – where actions do not go according to plan • e.g. intending to write 5mg of a drug but unintentionally writing 50mg. 2. Mistakes – where the plan itself is wrong • e.g. writing 50mg of a drug not knowing the usual dose is 5mg

Factors that cause error: • Inadequate knowledge of the patient and their clinical status • Inadequate drug knowledge • Calculation errors • Illegible handwriting • Drug name confusion • Poor history taking Tips for prescribing: • ALWAYS check allergy status before prescribing • Legible – black or dark blue (indelible) • Sign legibly to legalise – full signature/bleep • Use approved names and write in BLOCK LETTERS • Sign/date and give reason for discontinuations • NO abbreviations (only GTN acceptable) • Write doses in full (micrograms not mcg) • Antibiotics – state review date or course length • PRN medications – include – Max frequency – Max number of doses in 24 hours – indication

Intro to Prescribing...