Innovative Pharmacy Practices: Pharmacist Prescribing Cynthia Jackevicius, B.Sc.Phm., M.Sc., FCSHP Pharmacy Practice Leader, Heart & Circulation Program Associate, Women’s Health Program, University Health Network Assistant Professor, Faculty of Medicine & Pharmacy, U of Toronto Adjunct Scientist, Institute for Clinical Evaluative Sciences December 2002

Developing Innovative Practices F specific activities –warfarin dosing –monitoring drug therapy –total parenteral nutrition F practice sites –Heart Function Clinic –Thrombosis Treatment Program –Secondary Prevention Clinic –Emergency Department

What is prescribing? F To designate in writing a remedy for administration F Several related and complex steps –decide to initiate therapy u selection u prescription u monitoring u modification –decision to cease therapy

Who Prescribes? F Physicians F Nurse practitioners F Expanded role nurses F Clinical nurse specialists F Midwives F Optometrists F What about pharmacists?

Examples of Pharmacist Prescribing F Therapeutic interchange F Non-prescription Rx F Aminoglycoside dosing F Vancomycin dosing F TPN F Insulin dosing F Renal dosing program F HTN clinics F Lipid clinics F Refill clinics F Warfarin dosing F Cancer-related pain and antiemetic management

CSHP Survey F Therapeutic interchange-intervals70.6% F Order clarifications55.0% F Modify non-Rx medications39.4% F Pharmacokinetics29.8% F Routine labs23.0% F Pain service20.7%

Types of Prescribing Models F Independent F Dependent F Collaborative

Independent Prescribing F Prescribing practitioner is solely responsible for patient outcomes F Must possess legally defined levels of knowledge and skills to diagnose conditions –e.g., physician licensing process F Most Cdn pharmacy schools do not teach diagnostic and physical assessment skills required to practice at this level –not required skills for pharmacist licensure

Dependent Prescribing F Delegation of authority from an independent prescribing professional F Shared responsibility for patient outcomes F formal agreement usually containing: –written guidelines or protocols –description of responsibilities –description of documentation –policies for review and revision

Types of Dependent Prescribing F By protocol - most common –specific diseases, drugs, drug categories F According to formulary –delegation of prescribing for a limited list of medications –less explicit than by protocol F By patient referral –common in ambulatory practices

Collaborative Prescribing F Cooperative practice relationship between a pharmacist and a physician or practice group with legal authority to prescribe F not same as protocols since do not dictate the specific pharmacist activities

Collaborative Prescribing F “Ideal” model: –physician diagnoses and makes initial treatment decisions –pharmacist selects, initiates, monitors, modifies, continues and discontinues therapy as appropriate to achieve desired patient outcomes F Both share in responsibility and risk

CSHP Statement CSHP advocates the role of pharmacists as capable prescribers and supports the pharmacists’ role in a collaborative prescribing model to improve patient health outcomes and increase the successful and efficient delivery of pharmaceutical care.

Core elements for collaborative prescribing F Support from prescriber groups F Written declaration - contractual understanding F Explicit prescribing activities F Clear definition of scope of practice F When to contact physician F Procedures for documentation F Time limit - review, quality assurance

The Plan….. F rationale for the service F support from other departments –teamwork is imperative F supportive literature, if available F pilot test the service F evaluate the benefits F make necessary revisions F continue to justify the service

Potential Benefits F process “outcomes” vs outcome “outcomes” F structure, process and outcome F “hard” vs “soft” outcomes F clinical outcomes F financial outcomes

Prescribing Statements F Canadian Society of Hospital Pharmacists (CSHP) F American College of Clinical Pharmacy (ACCP) F American Society of Health-System Pharmacists (ASHP) F Canadian Pharmacists’ Association (CPhA) F National Association of Pharmacy Regulatory Authorities (NAPRA)

Monitoring Drug Therapy

F Role of the pharmacist –monitor drug therapy –prevent drug related adverse events –ensure accurate dosing for clinical efficacy F Sources of monitoring parameters –patient –written chart –electronic chart

20 Coumadin F Pharmacist Assisted Warfarin Dosing Program (PAWD) –Delegated Medical Act –Approved for use in the Cardiac Program –Pharmacists certification and CQI –Daily dosing by protocol according to INR

Coumadin F Issue: –INRs are not ordered routinely and information is not available for daily dosing. –Nurses have been ordering INR test as requested by the pharmacists but will no longer be doing this. F Request to CDS Committee –Pharmacists be granted authorization to order INR test for patients on PAWD Program.

Heparin- LMWH F Current hospital guidelines suggest to contact the pharmacists for difficult to dose patients (i.e. renal and obese patients). –Requires anti-Xa levels –Physicians are unfamiliar with ordering anti-Xa levels F Improper timing can lead to inappropriate dosing changes.

Timing of Anti-Xa levels in Renal Patients

Amiodarone F Amiodarone can have significant long term toxicity. –Hepatic/ thyroid/ pulmonary toxicity F Baseline function tests are required when initiating patients on amiodarone therapy. F This practice is not occurring, particularly for thyroid function –5/26 (19%) patients had TSH done –often delayed up to 7 days after initiating therapy

Aminoglycosides F UHN aminoglycoside guidelines require: –baseline Serum Creatinine prior to initiation of therapy and 3 times per week while on active therapy –24 hour trough levels for patients on 7 days or more of aminoglycosides F Pharmacists have been granted authorization to order the levels and SrCr but not the access to do so electronically. F (P&T and MAC February/April 1997)

Vancomycin F Baseline serum creatinine is required for initial dosing and ongoing monitoring. F In select patients vancomycin trough levels are required to monitor for efficacy and /or drug accumulation. F Pharmacists are often asked to provide consultations regarding vancomycin dosing. This often requires the ordering of SrCr and vancomycin levels.

SUMMARY F Request authorization for pharmacists to order the following tests: –INR –anti-Xa –TSH and LFT’s –Serum Creatinine –aminoglycoside trough levels –vancomycin trough levels F Approved by UHN Clinical Decision Support

Conclusion F Pharmacist prescribing occurs widely in hospital/institutional practice F Many opportunities exist for improving patient care with pharmacist prescribing F Pharmacy practice is evolving to encompass prescribing responsibilities F Useful tools are available to assist pharmacists with implementation (e.g., CSHP)