Similar, generic and reference medicines: do you know the difference between them?

Do you know the difference between a similar, generic and reference medicine? When purchasing a medicine at the pharmacy, the nomenclature of the different types can be a source of confusion — especially regarding the drug substitution rules prescribed by doctors.

According to a survey carried out by Ibope commissioned by Merck, 58% of Brazilians are unaware of the difference between generic, similar and reference drugs. The majority (69%) also do not have knowledge about the rules of interchangeability of drugs. The survey was carried out in September 2020 and heard 2,000 people from various regions of Brazil, all over 16 years old.

Understanding the differences between medications is extremely relevant, both in the medical consultation and when purchasing the medication. With that in mind, MinhaVida talked to general practitioner Rodrigo Correa to clarify the main doubts about generic, similar and reference medicines.

Reference drugs

The reference medicine, also known as “brand name”, for having a well-known trademark, is the one in which the efficacy, safety and quality have been proven by scientific studies. They are usually innovative products, registered with the National Health Surveillance Agency (Anvisa).

They are sold exclusively until the laboratory’s patent term expires, generally 10 to 20 years. After that time, other laboratories can use the same active principle and make copies of the reference drug, according to Rodrigo. To identify it, just observe if the box has a commercial name and, usually, a specific logo.

generic drugs

The generic drug contains the same IFA (active pharmaceutical ingredient, or simply active principle) of the reference drugs — as well as the same concentration, pharmaceutical form, route of administration and number of times to be used per day.

Learn more: 7 most common questions about generic drugs

The big difference between it and the reference is in the market valuesince this type of remedy must be at least 35% cheaper than the reference ones. This happens because, by following the same characteristics of the original drug, the generic manufacturer does not need to carry out all the research again.

Even so, every generic medicine is submitted to pharmaceutical equivalence tests carried out by laboratories accredited by Anvisa, in order to prove its safety and efficacy.

In the packaging of generics there is a yellow label containing the letter G and the inscription “Generic drug”🇧🇷 Since it has no brand, unlike the similar and the reference, what the consumer reads on the package is the active ingredient of the medicine.

Similar medicines

The similar drug is identified by brand or trade name and has the same active ingredient as a reference drug. The difference between them is related to factors such as expiry date, packaging, labeling and product size and shape.

In practice, the only difference between the similar and the generic drug is that this drug has a brand by which it is marketed.

It is important to note that a similar drug can only replace its respective reference drug after undergoing laboratory tests that prove its equivalence — just like generics.

This type of medicine must inform in the leaflet that they are substitutes for the originals. Anvisa has a list in which it informs which are the similar ones recognized as interchangeable, that is, equivalent to the respective reference medicines.

What are the rules for drug interchangeability?

The interchangeability indicates the possibility of replacing a drug prescribed by the health professional for a generic or similar medicine — as long as it appears on the Anvisa list as an interchangeable similar.

Current legislation provides for the interchangeability of medicines as follows: between generic medicine and its respective reference medicine; and between the similar drug and its respective reference drug.

A drug is only recognized as interchangeable if there is a pharmaceutical equivalence study between the parties to prove its effectiveness and safety. The study is always carried out between the reference drug and the study drug (generic or similar). Therefore, no similar medicine can be interchanged with a similar one, nor with generics.

It should be noted that not all drugs are interchangeable. For some categories, such as herbal, biological and specific drugs (such as vitamins, folic acid, minerals, quercetin, amino acids, among others), interchangeability may not happen. In this scenario, the patient must follow the treatment with the medicine prescribed by the doctor.