1. SUBJECT : PHARMACY PROFESSIONAL ETHICS, CLNP321
Dr. Mohammad Almermesh
Lecturer
Pharmacology Department
& Clinical Pharmacy Dep.
College of Pharmacy
University of Hail
LECTURE : 8

2.  Will be able to evaluate and select medications for therapeutic
interchange that are most appropriate for the needs of the
population from the perspectives of safety, effectiveness, and
cost.
 Will be familiar with therapeutic interchange that has the
potential to ensure quality of care and improve outcomes for
long-term care.
 Importance to assist with determining response to selected
therapy.
 Will be aware with the potential drug interactions that may
occur among therapeutic drug outcome.

3.  Therapeutic equivalents are drug products with different
chemical structures that are of the same therapeutic or
pharmacological class, and usually can be expected to have similar
outcomes and adverse reaction profiles when administered in
therapeutically equivalent doses.
 Therapeutic interchange is an authorized exchange of therapeutic
equivalents in accordance with previously established and
approved written guidelines or protocols.
 Therapeutic substitution is also known as therapeutic
interchange or therapeutic alternative.
 A therapeutic interchange program is a dynamic process that is
administered by an interdisciplinary committee that includes
physicians, pharmacists, and other health care professionals.

4.  Essential medicines :Essential medicines are those that
satisfy the priority health care needs of the population.
 According to the American Medical Association-AMA,
“therapeutic substitution means a drug product with a
different chemical structure but which is of the same
pharmacological and/or therapeutic class, and usually can be
expected to have similar therapeutic effects and adverse
reaction profiles when administered to patients in
therapeutically equivalent doses.”

5.  Therapeutic substitution is different from generic
substitution because generic substitution is limited to the
substitution of products that contain the same active
ingredient and are chemically identical.
 Therapeutic substitution policies permit the pharmacist the
authority to interchange one drug to another without the
prior consent from a prescriber according to the formulary
which is followed by the specific guidelines.

6.  A carefully selected essential medicines leads to better health
care, better drug management, and lower costs.
 Selection criteria: Like essential medicines are selected with
due regard to disease prevalence, evidence on efficacy and
safety, and comparative cost-effectiveness.
 Purpose: Essential medicines are intended to be available
within the context of functioning health systems at all times, in
adequate amounts, in the appropriate dosage forms, with
assured quality, and at a price the individual and the
community can afford.

7.  Before selecting an antibacterial the clinician must first
consider two factors—the patient and the known or likely
causative organism.
 Factors related to the patient which must be considered include
history of allergy, renal and hepatic function, susceptibility to
infection (i.e. whether immunocompromised).
 Patient ability to tolerate drugs by mouth, severity of illness,
ethnic origin, age, whether taking other medication and, if
female, whether pregnant, breast-feeding or taking an oral
contraceptive.

8.  An example of a rational approach to the selection of an
antibacterial is treatment of a urinary-tract infection in a
patient complaining of nausea and symptoms of a urinary-
tract infection in early pregnancy.
 The organism is reported as being resistant to ampicillin but
sensitive to nitrofurantoin (can cause nausea), gentamicin
(can be given only by injection and best avoided in
pregnancy), tetracycline (causes dental discoloration) and
trimethoprim (folate antagonist therefore theoretical
teratogenic risk), and cefalexin.
 The safest antibiotics in pregnancy are the penicillins and
cephalosporin; therefore, cefalexin would be indicated for
this patient.

9. The American College of Clinical Pharmacy (ACCP) supports
the therapeutic interchange when pharmacists and physicians
collaborate to develop the policies to provide patients with the
best possible care at the best overall price. The ACCP’s current
guidelines of therapeutic substitution are as follows:
 Therapeutic interchange is appropriate in institutional and
ambulatory settings that have a functioning formulary system
and Pharmacy and Therapeutic Committee or equivalent
advisory committee.
 A continuous drug use evaluation process must be in place for
regular review of endorsed therapeutic interchange policies
and procedures.

10.  Therapeutic interchange, as defined herein, may be executed
by pharmacist if the authorized prescriber is notified either
verbally or in writing within a reasonable time frame, and if
the pharmacists have access to medical records and
appropriate laboratory or other test results as required by the
therapeutic interchange policy. Exceptions to this procedure
must be stated clearly in the policy.
 The Pharmacy and Therapeutics Committee or its equivalent
should ensure that professional staffs are educated regarding
the rationale, policies, and procedures for therapeutic
interchange.
 The therapeutic interchange policies should define a
mechanism that enables authorized prescribers to disallow
therapeutic interchange.

11. In March 1999, The American Medical Association proposed
an act which they would like to see the modern law in each
state should follow as below.
 A pharmacist may not substitute a generically equivalent or
therapeutically alternative drug for a brand name drug
without prior authorization from or consultation with the
prescriber.
 If authorization is given by the prescriber, the pharmacist
shall substitute prescribed brand name drugs only with
those generically equivalent or therapeutically alternative
drugs meeting the definitions set forth in Section 3 of this
Act.

12.  When a pharmacist substitutes a generically equivalent or
therapeutically alternative drug, he or she must indicate the
status of the drug on the prescription label.
 A prescriber may expressly prohibit substitution of a
generically equivalent or therapeutically alternative drug by
writing “DISPENSE AS WRITTEN” or “NO SUBSTITUION” or
“BRAND NAME NECESSARY” or an equivalent statement
clearly indicating that substitution is not medically
appropriate and is not allowed.

13.  If the prohibition is communicated by the prescriber via
telephone, the pharmacist must indicate the prohibition on
the prescription.
 A prescriber may expressly permit substitution of a
generically equivalent or therapeutically alternative drug
by writing “GENERIC SUBSTITUION PERMITTED” or
“SUBSITUION WITH THERAPEUTIC ALTERNATIVE
PERMITTED.”
 If the prescriber has expressly prohibited substitution, the
pharmacist shall dispense the prescription exactly as
written or as communicated on the telephone to the
pharmacist by the prescriber.

14.  Cost savings: therapeutic substitution allows health
professional to replace one prescribed drug with another
qualitative drug that is therapeutically equivalent, in a cost-
effective manner.
 This results in the same clinical outcome for the patient and
cost-saving due to the price differential. However, the
therapeutic substitution is not always about lower drug
costs.
 Therapeutic substitution often occurs when “overall” health
care saving can be achieved.

15.  It can be to replace one drug with or more expensive one
where it may result in fewer treatment failures, better
patient adherence to treatment plan, and less side effects.
 With applying appropriate therapeutic substitution, health
professional may keep the cost down, improves the
patient’s access to more affordable health care, and
enhances the patient’s quality of life.
 Patient convenience: Therapeutic substitution allows
pharmacist to substitute another drug that is covered by
insurance without the prior consent of physician.
 It is convenience for patients because the process does not
block or delay prescriptions at the pharmacy counter

16.  In addition, the replacement drug may be more convenient
for the patient to take.
 For example, a patient is more likely to take a drug that
needs to be taken only two times a day rather than four
times per day, while they are therapeutically equivalent.
 Or a product that causes fewer side effects replaces the one
causing many side effects.
 Providers’ efficiency: once the therapeutic substitution is
approved, it eliminates a lot of hassles for pharmacists
because they do not need to contact the physician about the
prescription.

17. Several issues that pharmacists should be aware while
doing the therapeutic substitution :
High risk patients : such as diabetes patients, patients with
multiple diseases, or patients taking multiple drugs should
be recognized before restricting the patients to the
therapeutic substitution.
 The clinical problems may happen in these patients; while
healthier patients would not experience this.
 Drugs with narrow therapeutic windows such as digoxin,
warfarin sodium and theophylline are the higher risk
categories drugs.

18.  Department of Essential Drugs and Medicines Policy World Health
Organization, September 2003.
 American College of Clinical Pharmacy, Guidelines for Therapeutic
Interchange,1992.
 American Medical Association, Policy on Drug Formularies and
Therapeutic Interchange in Inpatient and Ambulatory Patient Care
Settings, Am J Hosp Pharm. 1994; 51:1808-10.
 British National Formulary., BNF-58.