The definition of a counterfeit drug as per WHO
“А counterfeit medicine is one which is deliberately and fraudulently mislabeled with respect to identity and/or source. Counterfeiting can apply to both branded and generic products and counterfeit products may include products with the correct ingredients or with the wrong ingredients, without active ingredients, with insufficient active ingredients or with fake packaging.”
Although the Indian Pharmacopeia does not define a counterfeit drug , it is assumed to be COPYING of drugs that mimick the original branded drug. As such the drug may fall either in the category of misbranded or spurious drugs. However it does not fall under the adulterated drug category. Adulterated drugs are not counterfeit drugs as they are made by the original manufacturer but are of substandard quality.
Counterfeit drugs may be
- Drugs without having any active ingredients which constitute a majority
- Drugs with incorrect quantities (usually lower quantities) of active ingredients
- Drugs with high levels of impurities and contaminants
- Drugs with incorrect excipients or ingredients (to cut cost of manufacture)
- Drugs with correct quantities of active ingredients but without appropriate packaging
- Copies of the original drug (very rare )
Of these drugs only the first three varieties are mostly harmful to the health of the person as they are likely to contain poisonous excipients.
It should be noted that counterfeit drugs have a direct correlation to the price and market of the branded drug. Most of the counterfeit drugs are copies of expensive drugs. These include the expensive antibiotics and hormones. Analgesics, steroids, and antihistamines with wide markets are also counterfeited. Other class of drugs includes patented drugs which cost little to manufacture but are priced higher because of patent exclusivity.
For more information , WHO’s article is recommended.
You can also read Pharmawiki’s article for clear understanding of the terms used
References:
http://www.who.int/medicines/services/counterfeit/overview/en/
http://en.wikipedia.org/wiki/Counterfeit_medications
Image courtesy : http://www.businessweek.com/articles/2013-01-17/inside-pfizers-fight-against-counterfeit-drugs