The practicalities of PRN prescribing

1
The practicalities of PRN prescribing

• Dr John Baker
• Lecturer

2
Aims Objectives

• To discuss prescription, administration PRN
  issues in acute mental health settings.
• To highlight areas where further knowledge is
  required.
• To address your aims and objectives.

3
Group work - 1 Understanding prescriptions and
their importance to clinical practice.

• Look at the prescription sheets for James Smith
  what are the issues (good points/areas for
  improvement) can you see?
• Firstly identify the regular medication what
  drug groups do they come from. What does the
  medication aim to do?
• What PRN medication has been prescribed?
• Examine the prescriptions what potential concerns
  do you have about them?
• Examine both prescriptions what patterns do you
  notice?
• Are there any concerns you have regarding the
  medication that James has had administered to him?

4
Group work 2 Dosing

• 21st January
• How much antipsychotic medication has James had?
  Is this an excessive dose?
• 28th January
• When administering antipsychotic medication to
  James what do you need to be aware of?

5
Working out Haloperidol doses

•  

Assume a 21 oralparenteral dose equivalence. to
calculate 24-hour doses. Parenteral doses
generally have a greater bioavailability than
oral doses therefore the maximum recommended
daily dose for each route of administration is
different. e.g. haloperidol maximum doses in 24
hours 30mg oral, 18mg IM. From Manchester Mental
Health Social Care Trust Rapid Tranquilisation
policy.
6

• Prescription quality
• Correct prescriptions form the foundations for
  good administration habits for nursing staff.
  Prescribing errors are the most common form of
  medication error and are often responsible for
  causing subsequent errors in administration.
  Prescriptions need to be correctly and clearly
  written (legible) with specific attention to
• Drug name
• Single dose (i.e. non-ranged) and within
  appropriate limits for example, as identified in
  the British National Formulary16
• Being signed
• Calculations used to determine dose
• Polypharmacy and/or high doses
• Additional considerations are needed for PRN
  prescriptions which are often of a poorer quality
  including
• Appropriate indication for use
• Total daily dose to be administered
• Single route per prescription
• Expiry/review or stopping date

7
Administration of medicines.

• The poor administration of medicines is one of
  the most common reasons for nurses losing their
  registration.
• The Department of Health (2004) estimates that
  there is a 5 error rate in the administration of
  medicines in hospitals, although precise figures
  remain unknown. Injectable drugs are associated
  with an increased risk.
• A recent study found that medicine trolleys are
  associated with an increased risk of
  administration error when compared to individual
  patient lockers
• The Nursing, Midwifery Council recommends the
  following principles for administering
  medications
• Know the medications, dosage, side effects,
  precautions and contra-indications.
• Be certain of the patient
• Be aware of care plan
• Check the prescription
• Consider dose, route and timing for the patient
• Check expiry date
• Check the patient is not allergic
• Make a clear and accurate record including those
  withheld or refused
• Countersign student nurses administrations

8
The Department of Health (2004) recommends the
5Rs for medication administration to reduce
common errors.