Understanding Generic Medicines

Module 1

The ultimate goal of this topic is to create awareness among pharmacists regarding prescribing and utilization of generic medicines

Learning outcomes

Describe "generic medicines" & "bioavailability" terms

Becoming familiar with "bioequivalence testing" concepts

Expose HCPs to conceptsof quality use of generic medicines

Module 2

Increased pharmaceutical costs have become a global challenge

Generic medicines provide savings in medicines costs due to their cheaper price

(Hassali, MA etal. 2009, WHO 2012)

Generic Product Definetions

Product marketed under the drug's non-proprietary approved name

Product marketed under a different brand name

Product from a company other than the innovator manufacturer

FDA Definition

Product which is identical or bioequivalent to the brand in terms of:

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• Dosage Form
• Safety
• Strength
• Route of administration

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• Quality
• Performance
• Intended use

WHO Defination

Pharmaceutical product intended to be interchangeable with innovator product & manufactured without a license from the innovator company and marketed AFTER the expiry date of the patent or other exclusive rights

Understanding Generic Medicines

Generic medicine approval

Generic medicine approved after doing the bioequivalence test with reference product with drug dissolution testing at various pH levels

(Gauzit R, 2012)

Generic manufacturers MUST prove that performance of generic drug is the SAME of reference product before it can be marketed

(Pearce G, 2004)

Generic medicines contain exactly the SAME active ingredient BUT sometimes DIFFERENT chemical form

Examples of erythromycin chemical forms

• Ethyl succinate
• Lactobionate
• Stearate
• Erythromycin base

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What about different formulations?

DIFFERENT formulations lead to differences in Solubility, Absorption & Bioavailability BETWEEN
Brand & Generic medicines

Differences between brand & generic medicines in terms of PHARMACOKINETICS may lead to controversy in the treatment of some chronic diseases

Generic medicines remain a valid choice of treatment IF there is NO evidence of INFERIORITY

Understanding Generic Medicines

Significant savings

Generic medicines in Malaysia cost 20-90% LESS than the price of their brand equivalents

(Shafie AA, 2008)

Generic medicines can be priced WELL BELLOW their innovator equivalents

(Crawford et al., 2006)

Generic manufacturer has ONLY to demonstrate BIOEQUIVALENCE between generic product and branded one to gain a PRODUCT LICENSE

Equal choices in the treatment of chronic illnesses

Initiation and continuation of therapy for various of chronic illnesses SHOULD involve the use of generic medicine as first line therapy BECAUSE the Gold Standards of these therapies are available NOW as generic medicines

(Sheppard A., 2012)

Start using generic medicines as a first line therapies will generate LONG-TERM SAVINGS by using safe, effective therapy & at an affordable price

(Sheppard A., 2012)

Generic prescription SHOULD be encouraged to PREVENT confusion due to different brand names & to DECREASE the commercial influence on medicine

(Chu C. et al., 2011)

Module 3

Drug Control Authority (DCA) made bioequivalence studies on generic medicines as MANDATORY requirement since 1999

Bioequivalence study reports are required as a PER-REQUISITE for registeration

Bioavailability & Bioequivalence studies play KEY ROLES in the drug development period to ensure the safety & effectiveness of generic medicines

(Chen ML. et al., 2011)

Bioavailabilty determines therapeutic efficacy BECAUSE it affects onset, intensity & duration of action

Bioequivalence Definition

Bioequivalence is absence of significant difference in the RATE & EXTENT which active ingredient or moiety in the pharmaceutical equivalents or pharmaceutical alternatives becomes available at the site of drug action when they administered in the same dose & under the same conditions in an appropriately designed study

(Meredith P., 2003; FDA)

Bioequivalence is achieved when two products generate IDENTICAL plasma concentrations in terms of active ingredient

Why bioequivalence is clinically IMPORTANT?

Because if two formulations are NOT equivalent, THEN this will lead to produce DIFFERENT clinical responses

Understanding Generic Medicines

What generic medicine must contains?

According to (Meredith P., 2003)

• Same active ingredient in identical amounts
• Same formulation
• Same administration route
• Meet standards of strength, purity, quality & identity

What things are allowed ti differ?

Generic products can differ in:

• Inactive ingredients (e.g. inert binders & fillers)
• Pill color and shape
• Specific manufacturing process

Bioequivalence is established by studies in humans (in-vivo tests) that helps to measure BIOAVAILABILITY

Exception

IF the drugs have HIGH solubility, permeability & dissolution profile, THEN they will given BIO-WAIVER status
(in-vitro bioequivalence test ONLY)

(Nightingale SL, 1987)

Pharmacovigilance plan SHOULD be established at the time of approval of generic product (EMEA, 2012)

Pharmacovigilance studies help to detect, assess, understand & prevent adverse effects after marketing (Locateli F, 2006)

In bioequivalence study, generic and innovator drug products are given to the same individual WHO acts as a control for his own ... This design helps reduce the number of subjects

(Nightingale SL, 1987)

Parameters measured in (BE) studies

Parameters

• AUC0-t
• AUC0-infinity
• Cmax
• Tmax

When bioequivalence achieved?

90% confidence interval for the ratio of Cmax, AUC0-t & AUC0-inf values of generic medication OVER those of brand LIES within the range of 80-125%

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Module 4

Brand Switching

Brand switching key points

• Consumer's decision
• Patients should know the name of active ingredient
• Affected by price promotions

Brand switching key points

• Number of available brands
• Frequency of purchase
• Affected by price promotions

Pharmacists need the knowledge and skills to provide effective and accurate patient education and consultation regarding brand switching

(ASHP, 1997)

Basic Skills

1. Welcoming

• Give patient good impression.
• Checking the prescription.
• Explain to patients about generic medicines.

2. Questioning

• Questions should be open ... NOT closed, limited or leading
• Don't interrupt UNLESS you need to seek clarification

2. Questioning

• Listen and maintain a flow
• Don't interrupt UNLESS you need to seek clarification
• Break the current chain of thoughts and focus is inappropriate

3. Listening

• Be attentive
• Maintain eye contact
• Taking notes when patient speaks is optional

4. Responsing

• Clarifying points
• Summarizing
• Show patients empathy

5. Explanaing

• Use language that the patient understands.
• Give important information first.

5. Explanaing

• Repeat important points
• Provide written information or visual aids

6. Closuring

• Issue of the prescription
• Clarify what is expected of the patient
• Make correct and adequte notes

Conclusion

HCPs should be aware of concepts involved in bioequivalence testing, and be able to display any myths about GM & provide advice to both doctors and patients on the rational use of GM