THE HOSPITAL FORMULARY SYSTEM
Generic Equivalence
Drugs are deemed generically equivalent if they can be expected to produce the same therapeutic outcome and toxicity.
Generic Substitution
Drugs and drug products that contain the same active ingredient(s) and are chemically identical in strength, concentration, dosage form and route of administration to the drug prescribed can be substituted (e.g. diltiazem 30 mg tablet for Cardizem 30 mg tablet). Prescribers may override a generic substitution if a valid reason is provided (e.g. patient allergy). The P & T Committee is responsible for determining which drugs are acceptable for generic substitution. Pharmacists are responsible for determining which products are purchased and dispensed as generic substitutes. Dispensing a generic substitute does not require notification of the prescriber. In Ontario, the ODB Formulary indicates which drugs are interchangeable under the law.
Therapeutic
Therapeutic means to pertain to, or effective in, the treatment of disease.
Therapeutic Equivalence
Drugs are deemed therapeutically equivalent if they can be expected to produce essentially the same therapeutic outcome and toxicity.
Therapeutic Interchange
Therapeutic Interchange is the term used to describe the interchange of various therapeutically equivalent drug products by Pharmacists. Therapeutic Interchange is based on formal arrangements made between pharmacists and authorized prescribers. Established and jointly agreed upon conditions for interchange must already be in place. A therapeutic substitution policy provides for automatic dispensing (Auto-Sub) of a particular drug in place of a chemically different but therapeutically equivalent drug product (e.g. amoxicillin for cloxacillin). Arrangements can vary from simple understandings (e.g. same dose and dosage form) to complex protocols (e.g. change in strength and directions).
Example 1 - famotidine 20 mg po hs is ordered (H2 Receptor Antagonist)
Ranitidine 150 mg po hs is dispensed (as per policy)
Example 2 - ampicillin 500 mg po qid is ordered
amoxicillin 500 mg po q8h is dispensed (as per policy)
In both cases a communication directive must be issued to the patient care (Nursing) unit to inform the nurse of the change so that delay in therapy will not occur due to confusion over the medication supplied by pharmacy.
Process of Therapeutic Interchange (Auto-Sub)
The process of Therapeutic Interchange begins when a drug included in the policy is ordered. The Pharmacy department in turn automatically sends the appropriate substitute along with a medication communication directive stating the substitution. The Nurse then rewrites the order on the patient’s chart (if the Physician is unavailable). The Physician must co-sign the rewritten order as soon as he/she becomes available.
Approval of Therapeutic Interchange
Therapeutic Interchange requires decision making by The P & T Committee based on evidence-based research methods in determining equivalency. Decisions should be routinely reviewed and revised. All Auto-Subs must include notification to the Nursing staff to prevent misinterpretation as a medication error and unnecessary delay in therapy.
Patient Diagnosis & Therapeutic Interchange
Therapeutic Interchange may not be appropriate for all patients. The Prescriber and/or patient may need to be consulted by the Pharmacist who will assess a patient’s diagnosis. Alternate medication or dosing may be required.
Do Not Substitute (No Sub)
A prescriber may override any therapeutic interchange for an individual patient by designating “Do Not Substitute” on the medication order and following the processes in place and detailed in the Formulary.
Benefits of Therapeutic Interchange
Therapeutic Interchange avoids stocking of closely related products which results in economic benefits to the hospital by limiting the number of different products on hand and allowing for volume purchasing. It also minimizes the number of Physician contacts (by Pharmacy) required for order clarification. Most importantly, it enhances patient care by allowing for NO delay in initiating therapy.
Therapeutic Interchange Classifications
Policies concerning Therapeutic Interchange are often made for certain categories of drugs. Drug classifications typically include Antacids, Antifungal vaginal creams, Antibiotics, Topical Corticosteroids, Levothyroxine, Proton pump inhibitors (PPIs), Statins, Calcium Channel Blockers (CCBs), and Multivitamins. View Tables 1-7 in the document on Therapeutic Interchange for Vancouver Community of Care. Which classes of drugs are named in the Tables? Which drug (and strength) would be sent if Crestor 40 mg daily was ordered at this hospital? (See Table 5)
Restricted Drug
A Restricted Drug is therapeutic agent (admitted to the formulary) for use only by a specific group of Physicians determined and designated by the P & T Committee. A Restricted Drug is dispensed only if prescribed by a full time active medical staff member of the designated group of Physicians. Other medical staff may prescribe the drug for an individual patient if they have the medication order authorized by one of the designated Physicians. Alternatively, drugs may be restricted for P & T Committee approved indications (e.g. Antibiotic use limited to ensure compliance with approved indication).
Formulary System Management
Changes to the formulary are ongoing to optimize patient care through rational selection and use of drugs and drug products. Pharmacists play a primary role in assessing the safety and efficacy of pharmaceuticals suggested for addition to or deletion from the formulary. Well established techniques are used to continuously assess its effectiveness. This results in quality improvement of the overall drug use process. Goals of a Formulary System are to reduce stock of closely related products, promote the use of drugs with a single active ingredient, promote better inventory control, allow more rational and economic purchasing, and to reduce delay in initiating therapy. Effective communication and understanding among Pharmacists, Physicians, other health-care providers and the P&T Committee must be timely and routine.
Techniques of formulary management fall into 3 general categories: 1. Drug use evaluation, 2. Drug product selection, and 3. Formulary Maintenance
1. Drug Use Evaluation (DUE) - DUE is an ongoing, structured, organizationally authorized process designed to ensure that drugs are used appropriately, safely and effectively. It represents part of an overall Quality Assurance program. The P & T Committee should (must!) be involved in the DUE process. Effective DUE begins with drug use criteria or treatment guidelines approved by the P & T Committee. The process involves measuring and comparing patient outcomes of treatment which did, or did not, comply with approved criteria or guidelines. Comparative information of the criteria or guidelines is used to revise criteria or guidelines, encourage compliance of criteria or guidelines, initiate educational programs and make changes to the formulary.
Drug Use Criteria
The P & T Committee may establish criteria to promote the appropriate use of drugs that pose potential efficacy, toxicity or utilization problems. The criteria dictates how, or under what conditions, a drug is recommended for use. The 3 general criteria are: Diagnostic, Prescriber and Drug-specific (each of which can be used independently or in combination with the others).
Diagnostic Criteria - Identifies indications that constitute acceptable uses for a Formulary drug. Protocols for restriction of use of a Formulary drug to specific diagnosis or medical condition is established by the P & T Committee (e.g. cefotaxime restricted for bowel surgery patients).
Prescriber Criteria - Identifies Prescribers approved to use specific Formulary drugs or drug classes (e.g. emergency room Physicians as only approved prescribers for thrombolytic drugs).
Drug-specific Criteria - Identifies approved doses, frequency of administration, duration of therapy, etc. (e.g. limiting the dosing of a long-acting injectable antibiotic to once every 24 hours).
Treatment Guidelines
Treatment Guidelines are similar to drug use criteria. However, Treatment Guidelines focus on disease-based drug therapy vs a specific drug and are used to recommend a therapeutic approach to specific diseases. The Guidelines are intended to identify the use of several different drugs depending on the specific disease or patient characteristics. They are developed and approved by the P & T Committee for high risk, high volume or problem-prone diseases such as Community-Acquired Pneumonia (CAP), reflux esophagitis, otitis media or Bone marrow transplant.
2. Drug Product Selection - Pharmacists and Prescribers must understand the concept of therapeutic equivalence to ensure proper application of generic substitution and therapeutic interchange principles. Drug product selection includes evaluation and assessment of Bioequivalence data, Storage, Dispensing, Administration characteristics and Cost.
3. Formulary Maintenance - This includes Therapeutic drug class review, Processes for addition or deletion of drugs, and Use of non-formulary drugs. Pharmacists play a leadership role in the development and presentation of information to the P & T Committee for decision making purposes. Best success in the maintenance of the Formulary requires the full participation of the Medical Staff in the development and review of information.
Therapeutic Drug Class Review - Review of use and therapeutic effects of several classes of drugs should be completed each year. This may be prompted by a rising number of ADRs, new information available in medical literature, or rising drug class expenditures. The goal is to identify preferred agents based on effectiveness, toxicity or cost differences within the same drug class. Outcomes include development of new drug use criteria, new treatment guidelines or changes to the formulary.
Formulary Addition or Deletion - Approved policies and procedures are developed by the P & T Committee for requesting changes to the formulary. This typically involves submission of a request to the P & T Committee by Pharmacists or medical staff members. Consideration of a drug for addition or deletion should include a review of an evaluation report (monograph) prepared by the Pharmacy department.
Standardized Evaluation Report (Monograph)
A drug monograph should include the Generic name of drug product, Trade name(s), Source of supply (manufacturer), AHFS-DI number, Pharmacologic classification, Therapeutic indication, Dosage forms, Bioavailability and pharmacokinetics, Dosage range, Adverse effects and toxicities, Special precautions, and Comparisons similar to the information provided in the Compendium of Pharmaceuticals and Specialities (CPS).
Recommendations for additions of drugs to the Formulary may be “Uncontrolled” (for use by all), “Monitored” (for use by all but monitored), “Restricted” (for use by medical staff of a specific service/department) or “Conditional” (for use by all medical staff for a specified time). An impact statement describing the effects on quality and cost of patient care and drug therapy should accompany each request for deletion of a drug from the current formulary.
Use of Non-Formulary Drugs - Only formulary drugs are endorsed as appropriate for routine use. A process must be in place for approval of non-formulary drug usage because individual or unique patient needs can and do exist and therefore may not be satisfied by the use of the formulary drugs. The process should include the generation of information on the use of non-formulary drugs, including frequency of use, in order for the P & T Committee to be able to review trends on usage which may influence formulary additions/deletions. Details on the procedure for obtaining non-formulary drugs in a timely manner must be clear and known to those affected (i.e. Prescribers, Nurses, Pharmacy staff). The Pharmacy department must ensure that the prescribing Physician is aware that delay in initiation of therapy is unavoidable. A Non-Formulary drug will not be dispensed unless the Physician/Prescriber orders it for a specific patient via an established procedure (e.g. by using a "Request to Use a Non-Formulary Drug” form). If the process involves the use of a form it must be completed for each drug and each patient. Forms may be utilized for consideration of adding a non-formulary drug to the existing formulary.
Special Procurement Drugs
Special Procurement Drugs are Non-Formulary drugs required for a specific patient, for a specific reason and duration. The prescriber must provide information to the Pharmacist regarding the patient and the reason for use OR the patient’s family may instead buy the medication for the patient and have them use their own supply. This is documented in the patient's profile as “Patient’s Own Supply.”
Informal Therapeutic Trial Drugs
Informal Therapeutic Trial Drugs are Non-Formulary drugs that have been requested by a Physician or department for a number of patients. After the drug has been issued for a year in the hospital, the P & T Committee members will determine whether or not to include the drug in the formulary as a regular drug. A “Request to Use a Non-Formulary Drug for an Informal Therapeutic Trial” form (or a similar process established by the particular hospital) must be completed by the physician.
Prescriber “Buy-In”
Prescriber acceptance of the formulary management process is essential to ensure quality improvement. Pharmacists foster this acceptance by clarifying and supporting established goals and processes. Prescribers need to be actively involved in developing the techniques used to manage the formulary system in order to guarantee compliance.
CHECKPOINT Question ONE: Try your hand at Therapeutic Interchange at Fanshawe Hospital with an order that reads: Tagamet 300 mg IV qid. Which Formulary drug, dose and frequency would you substitute according to Hospital policy? Check your answer here. How did you do? Are you getting ready for Hospital Pharmacy practice?
Generic Equivalence
Drugs are deemed generically equivalent if they can be expected to produce the same therapeutic outcome and toxicity.
Generic Substitution
Drugs and drug products that contain the same active ingredient(s) and are chemically identical in strength, concentration, dosage form and route of administration to the drug prescribed can be substituted (e.g. diltiazem 30 mg tablet for Cardizem 30 mg tablet). Prescribers may override a generic substitution if a valid reason is provided (e.g. patient allergy). The P & T Committee is responsible for determining which drugs are acceptable for generic substitution. Pharmacists are responsible for determining which products are purchased and dispensed as generic substitutes. Dispensing a generic substitute does not require notification of the prescriber. In Ontario, the ODB Formulary indicates which drugs are interchangeable under the law.
Therapeutic
Therapeutic means to pertain to, or effective in, the treatment of disease.
Therapeutic Equivalence
Drugs are deemed therapeutically equivalent if they can be expected to produce essentially the same therapeutic outcome and toxicity.
Therapeutic Interchange
Therapeutic Interchange is the term used to describe the interchange of various therapeutically equivalent drug products by Pharmacists. Therapeutic Interchange is based on formal arrangements made between pharmacists and authorized prescribers. Established and jointly agreed upon conditions for interchange must already be in place. A therapeutic substitution policy provides for automatic dispensing (Auto-Sub) of a particular drug in place of a chemically different but therapeutically equivalent drug product (e.g. amoxicillin for cloxacillin). Arrangements can vary from simple understandings (e.g. same dose and dosage form) to complex protocols (e.g. change in strength and directions).
Example 1 - famotidine 20 mg po hs is ordered (H2 Receptor Antagonist)
Ranitidine 150 mg po hs is dispensed (as per policy)
Example 2 - ampicillin 500 mg po qid is ordered
amoxicillin 500 mg po q8h is dispensed (as per policy)
In both cases a communication directive must be issued to the patient care (Nursing) unit to inform the nurse of the change so that delay in therapy will not occur due to confusion over the medication supplied by pharmacy.
Process of Therapeutic Interchange (Auto-Sub)
The process of Therapeutic Interchange begins when a drug included in the policy is ordered. The Pharmacy department in turn automatically sends the appropriate substitute along with a medication communication directive stating the substitution. The Nurse then rewrites the order on the patient’s chart (if the Physician is unavailable). The Physician must co-sign the rewritten order as soon as he/she becomes available.
Approval of Therapeutic Interchange
Therapeutic Interchange requires decision making by The P & T Committee based on evidence-based research methods in determining equivalency. Decisions should be routinely reviewed and revised. All Auto-Subs must include notification to the Nursing staff to prevent misinterpretation as a medication error and unnecessary delay in therapy.
Patient Diagnosis & Therapeutic Interchange
Therapeutic Interchange may not be appropriate for all patients. The Prescriber and/or patient may need to be consulted by the Pharmacist who will assess a patient’s diagnosis. Alternate medication or dosing may be required.
Do Not Substitute (No Sub)
A prescriber may override any therapeutic interchange for an individual patient by designating “Do Not Substitute” on the medication order and following the processes in place and detailed in the Formulary.
Benefits of Therapeutic Interchange
Therapeutic Interchange avoids stocking of closely related products which results in economic benefits to the hospital by limiting the number of different products on hand and allowing for volume purchasing. It also minimizes the number of Physician contacts (by Pharmacy) required for order clarification. Most importantly, it enhances patient care by allowing for NO delay in initiating therapy.
Therapeutic Interchange Classifications
Policies concerning Therapeutic Interchange are often made for certain categories of drugs. Drug classifications typically include Antacids, Antifungal vaginal creams, Antibiotics, Topical Corticosteroids, Levothyroxine, Proton pump inhibitors (PPIs), Statins, Calcium Channel Blockers (CCBs), and Multivitamins. View Tables 1-7 in the document on Therapeutic Interchange for Vancouver Community of Care. Which classes of drugs are named in the Tables? Which drug (and strength) would be sent if Crestor 40 mg daily was ordered at this hospital? (See Table 5)
Restricted Drug
A Restricted Drug is therapeutic agent (admitted to the formulary) for use only by a specific group of Physicians determined and designated by the P & T Committee. A Restricted Drug is dispensed only if prescribed by a full time active medical staff member of the designated group of Physicians. Other medical staff may prescribe the drug for an individual patient if they have the medication order authorized by one of the designated Physicians. Alternatively, drugs may be restricted for P & T Committee approved indications (e.g. Antibiotic use limited to ensure compliance with approved indication).
Formulary System Management
Changes to the formulary are ongoing to optimize patient care through rational selection and use of drugs and drug products. Pharmacists play a primary role in assessing the safety and efficacy of pharmaceuticals suggested for addition to or deletion from the formulary. Well established techniques are used to continuously assess its effectiveness. This results in quality improvement of the overall drug use process. Goals of a Formulary System are to reduce stock of closely related products, promote the use of drugs with a single active ingredient, promote better inventory control, allow more rational and economic purchasing, and to reduce delay in initiating therapy. Effective communication and understanding among Pharmacists, Physicians, other health-care providers and the P&T Committee must be timely and routine.
Techniques of formulary management fall into 3 general categories: 1. Drug use evaluation, 2. Drug product selection, and 3. Formulary Maintenance
1. Drug Use Evaluation (DUE) - DUE is an ongoing, structured, organizationally authorized process designed to ensure that drugs are used appropriately, safely and effectively. It represents part of an overall Quality Assurance program. The P & T Committee should (must!) be involved in the DUE process. Effective DUE begins with drug use criteria or treatment guidelines approved by the P & T Committee. The process involves measuring and comparing patient outcomes of treatment which did, or did not, comply with approved criteria or guidelines. Comparative information of the criteria or guidelines is used to revise criteria or guidelines, encourage compliance of criteria or guidelines, initiate educational programs and make changes to the formulary.
Drug Use Criteria
The P & T Committee may establish criteria to promote the appropriate use of drugs that pose potential efficacy, toxicity or utilization problems. The criteria dictates how, or under what conditions, a drug is recommended for use. The 3 general criteria are: Diagnostic, Prescriber and Drug-specific (each of which can be used independently or in combination with the others).
Diagnostic Criteria - Identifies indications that constitute acceptable uses for a Formulary drug. Protocols for restriction of use of a Formulary drug to specific diagnosis or medical condition is established by the P & T Committee (e.g. cefotaxime restricted for bowel surgery patients).
Prescriber Criteria - Identifies Prescribers approved to use specific Formulary drugs or drug classes (e.g. emergency room Physicians as only approved prescribers for thrombolytic drugs).
Drug-specific Criteria - Identifies approved doses, frequency of administration, duration of therapy, etc. (e.g. limiting the dosing of a long-acting injectable antibiotic to once every 24 hours).
Treatment Guidelines
Treatment Guidelines are similar to drug use criteria. However, Treatment Guidelines focus on disease-based drug therapy vs a specific drug and are used to recommend a therapeutic approach to specific diseases. The Guidelines are intended to identify the use of several different drugs depending on the specific disease or patient characteristics. They are developed and approved by the P & T Committee for high risk, high volume or problem-prone diseases such as Community-Acquired Pneumonia (CAP), reflux esophagitis, otitis media or Bone marrow transplant.
2. Drug Product Selection - Pharmacists and Prescribers must understand the concept of therapeutic equivalence to ensure proper application of generic substitution and therapeutic interchange principles. Drug product selection includes evaluation and assessment of Bioequivalence data, Storage, Dispensing, Administration characteristics and Cost.
3. Formulary Maintenance - This includes Therapeutic drug class review, Processes for addition or deletion of drugs, and Use of non-formulary drugs. Pharmacists play a leadership role in the development and presentation of information to the P & T Committee for decision making purposes. Best success in the maintenance of the Formulary requires the full participation of the Medical Staff in the development and review of information.
Therapeutic Drug Class Review - Review of use and therapeutic effects of several classes of drugs should be completed each year. This may be prompted by a rising number of ADRs, new information available in medical literature, or rising drug class expenditures. The goal is to identify preferred agents based on effectiveness, toxicity or cost differences within the same drug class. Outcomes include development of new drug use criteria, new treatment guidelines or changes to the formulary.
Formulary Addition or Deletion - Approved policies and procedures are developed by the P & T Committee for requesting changes to the formulary. This typically involves submission of a request to the P & T Committee by Pharmacists or medical staff members. Consideration of a drug for addition or deletion should include a review of an evaluation report (monograph) prepared by the Pharmacy department.
Standardized Evaluation Report (Monograph)
A drug monograph should include the Generic name of drug product, Trade name(s), Source of supply (manufacturer), AHFS-DI number, Pharmacologic classification, Therapeutic indication, Dosage forms, Bioavailability and pharmacokinetics, Dosage range, Adverse effects and toxicities, Special precautions, and Comparisons similar to the information provided in the Compendium of Pharmaceuticals and Specialities (CPS).
Recommendations for additions of drugs to the Formulary may be “Uncontrolled” (for use by all), “Monitored” (for use by all but monitored), “Restricted” (for use by medical staff of a specific service/department) or “Conditional” (for use by all medical staff for a specified time). An impact statement describing the effects on quality and cost of patient care and drug therapy should accompany each request for deletion of a drug from the current formulary.
Use of Non-Formulary Drugs - Only formulary drugs are endorsed as appropriate for routine use. A process must be in place for approval of non-formulary drug usage because individual or unique patient needs can and do exist and therefore may not be satisfied by the use of the formulary drugs. The process should include the generation of information on the use of non-formulary drugs, including frequency of use, in order for the P & T Committee to be able to review trends on usage which may influence formulary additions/deletions. Details on the procedure for obtaining non-formulary drugs in a timely manner must be clear and known to those affected (i.e. Prescribers, Nurses, Pharmacy staff). The Pharmacy department must ensure that the prescribing Physician is aware that delay in initiation of therapy is unavoidable. A Non-Formulary drug will not be dispensed unless the Physician/Prescriber orders it for a specific patient via an established procedure (e.g. by using a "Request to Use a Non-Formulary Drug” form). If the process involves the use of a form it must be completed for each drug and each patient. Forms may be utilized for consideration of adding a non-formulary drug to the existing formulary.
Special Procurement Drugs
Special Procurement Drugs are Non-Formulary drugs required for a specific patient, for a specific reason and duration. The prescriber must provide information to the Pharmacist regarding the patient and the reason for use OR the patient’s family may instead buy the medication for the patient and have them use their own supply. This is documented in the patient's profile as “Patient’s Own Supply.”
Informal Therapeutic Trial Drugs
Informal Therapeutic Trial Drugs are Non-Formulary drugs that have been requested by a Physician or department for a number of patients. After the drug has been issued for a year in the hospital, the P & T Committee members will determine whether or not to include the drug in the formulary as a regular drug. A “Request to Use a Non-Formulary Drug for an Informal Therapeutic Trial” form (or a similar process established by the particular hospital) must be completed by the physician.
Prescriber “Buy-In”
Prescriber acceptance of the formulary management process is essential to ensure quality improvement. Pharmacists foster this acceptance by clarifying and supporting established goals and processes. Prescribers need to be actively involved in developing the techniques used to manage the formulary system in order to guarantee compliance.
CHECKPOINT Question ONE: Try your hand at Therapeutic Interchange at Fanshawe Hospital with an order that reads: Tagamet 300 mg IV qid. Which Formulary drug, dose and frequency would you substitute according to Hospital policy? Check your answer here. How did you do? Are you getting ready for Hospital Pharmacy practice?