Patient groups and the Ministry of Food and Drug Safety are running parallel over the safety and efficacy of generic drugs for Parkinson's.
Industry insiders are watching how the dispute continues amid mounting patient dissatisfaction with generic drugs.
The bickering began in December 2021 when global pharmaceutical giant Roche suspended the domestic supply of its original Parkinson's disease drug, Madopar Tab (benserazide hydrochloride-levodopa), citing deteriorating profitability and lowered drug prices.
In July 2021, Merck (MSD) decided to withdraw another Parkinson's drug, Sinemet (carbidopa-levodopa), from the country.
The decisions to withdraw these drugs, prescribed to patients for a long time, were met with voices of concern from clinical fields.
There have been complaints from patients who experienced adverse reactions, unlike the original drug. Demands are still high for the resupply of Madopar tablets.
The ministry and Roche Korea have discussed resupplying the drug until recently, but the talks fell through.
The frustration of patients who have to take drugs consistently is growing. Earlier this year, a petition was posted to resume the supply of Madopar. More recently, a claim was posted on Petition24, pointing out that some generic drugs for Parkinson's disease need to be re-verified for safety.
"I am a 20-year Parkinson's patient taking the same medication for 20 years without skipping a day. I have been prescribed relatively cheap generic versions of the drug since the patent expired a few years ago,” the petitioner said. “I accepted the reality gladly and have taken relatively cheaper generic drugs. All of them have passed the bioequivalence test."
After taking medicines for a long time, one can feel it if the effect is slightly different. The petitioner said that some of the generics have side effects that are not present in the original drug, and some of the generics have different effects that call into question the mechanism of action. Among the Parkinson's generics, he added that drugs like PK Merz have the same effect as the original drug despite being generic.
"I start to doubt the validity of the bioequivalence test, and my conclusion was that even if the drug has passed the bioequivalence test, the effectiveness and side effects of the generic drug may be different," the petitioner said. “I am urging the creation of a bioequivalence test validation team of experts to see if there are additional criteria for generic drugs besides the bioequivalence test if new criteria are needed, and the creation of an international standard for generic drugs recognized worldwide."
Besides, there are complaints about Myung In Pharmaceutical's generic drug Myungdopar, a generic version of Madopar, on the online cafe “Parkinson's Disease,” where Parkinson's patients and their families are members.
"It is no longer a problem of supply of Madopar and Myungdopar, but a problem of Myung In Pharmaceutical making copycat drugs," one poster said. "I have been taking Requip and Mirapex, and I have been taking Sinemet and Madopar for a little over 10 years. It was only when I started taking Perkin three or four years ago that my health rapidly declined."
The patient said that he had no problems when, aside from Madopar, he took GSK's Requip (ropinirole hydrochloride), Boehringer-Ingelheim's Mirapex (pramipexole hydrochloride monohydrate), and MSD's Sinemet, but started experiencing new adverse reactions after taking Perkin, a generic version of Sinemet from Myung In Pharm.
However, the ministry expresses perplexion by the demand to recertify the safety and efficacy of generic drugs. The agency believes there is no need to revalidate drugs that have passed the bioequivalence test.
"It is necessary for generic drugs to undergo bioequivalence with the original drug (control drug) to receive approval. When bioequivalence is demonstrated, the safety and efficacy are equivalent to the original drug," said an official from the National Institute for Food and Drug Safety in a recent meeting with journalists covering the ministry.
When asked if the ministry plans to change the bioequivalence test criteria, an official from the Pharmaceutical Policy Division also drew the line at such a possibility.
"Currently, the bioequivalence test is operated appropriately according to the relevant regulations, and no further action is deemed necessary," the official replied.