Feb 28, 2020: The U.S. FDA has approved an application for the first generic of Daraprim (pyrimethamine) tablets for the treatment of toxoplasmosis (an infection caused by the parasite Toxoplasma gondii) when used with a sulfonamide (a group of medicines used to treat bacterial infections).
Toxoplasmosis is an infection caused by a single-celled parasite named Toxoplasma gondii that can cause brain, eye or other organ damage if severe. A toxoplasma infection can occur, inter alia, by eating undercooked, contaminated meat or shellfish; drinking water contaminated with toxoplasma; or by accidental swallowing of the parasite through contact with toxoplasma-containing cat feces. It is considered the leading cause of death in the United States due to foodborne disease.
In pregnant women and people with weak immune systems, such as those with HIV or AIDS, those undergoing other forms of chemotherapy and those who have recently received an organ transplant, serious toxoplasmosis is more likely. However, even people with healthy immune systems can occasionally experience toxoplasmosis damage to the eyes.One focus area under the action plan is to improve the efficiency of the generic drug production, review and approval process, and to close loopholes that allow brand-name drug companies to avoid generic competition.
As part of these important efforts, the FDA maintains a list of off-patent, off-exclusivity drug products without an approved generic in order to improve transparency and support the development and submission of applications for drugs with limited competition. Pyrimethamine is incorporated on this list. The FDA also prioritizes the review of the submissions for generic drugs for which there are fewer than three approved generic versions for the reference listed drug (RLD) and for which there are no blocking patents or exclusivities on the RLD.
In addition, certain “gaming” tactics have been used at times to delay generic competition. One example is when brand-name drug manufacturers attempt to prevent potential generic applicants from obtaining samples of the certain medicines necessary to support approval of a generic drug application. To increase clarity on this subject, the FDA posted a list describing all drugs for which a prospective generic applicant has received an inquiry concerning the limited distribution of the reference drug. Daraprim appears on this chart.
The most common side effects for pyrimethamine include hypersensitivity reactions (immune responses) that can irregularly be severe, such as Stevens-Johnson syndrome and toxic epidermal necrolysis (two forms of the same life-threatening disease that causes rash, skin peeling and sores on the mucous membranes), erythema multiforme (a skin disorder with bulls-eye-shaped lesions), anaphylaxis (a severe allergic reaction that may include difficulty breathing and shock) and hyperphenylalaninemia (elevated concentration of the amino acid phenylalanine in the blood), particularly when pyrimethamine is administered at the same time as a sulfonamide.
“Pyrimethamine should not be used in patients with known hypersensitivity to pyrimethamine or with documented megaloblastic anemia because of folate (a naturally-occurring B vitamin) deficiency. Women who takes pyrimethamine should not become pregnant. Patients should keep pyrimethamine out of the reach of children.”
A small “starting” dose for toxoplasmosis is recommended in patients with convulsive disorders in order to avoid the potential nervous system toxicity of pyrimethamine. Pyrimethamine should be used with caution in patients with impaired renal (kidney) or hepatic (liver) function or in patients with possible folate deficiency, such as individuals with malabsorption syndrome, alcoholism or pregnancy, and those receiving therapy, such as phenytoin (an anti-epileptic drug), affecting folate levels.
The sponsor of the approved generic version of the Daraprim Tablets is Cerovene Inc.
The FDA, an agency within the U.S. Department of Health and Human Services, protects the public health by assuring the safety, efficiency, and security of human and veterinary drugs, vaccines and other biological products for the human use, and medical devices. In addition, agency is responsible for the safety and security of our nation’s food supply, cosmetics, dietary supplements, products that give off electronic radiation, and for regulating tobacco products.
https://www.fda.gov/news-events/press-announcements/fda-approves-first-generic-daraprim
