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U.S. Department of Health and Human Services


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Questions and Answers for Consumers about FDA's Action Involving Unapproved Nitroglycerin Sublingual Tablets 


What action is FDA taking regarding Sublingual Nitroglycerin Tablets, 0.3 mg, 0.4 mg, and 0.6 mg?

FDA today sent warning letters to two companies -- Glenmark Generics Inc and Konec, Inc-- ordering them to cease marketing unapproved sublingual nitroglycerin tablets, 0.3 mg, 0.4 mg, and 0.6 mg.  Sublingual nitroglycerin tablets are used to relieve chest pain once it starts, and to prevent an acute attack.  Consumers will continue to have access to  FDA-approved versions of 0.3 mg, 0.4 mg and 0.6 mg sublingual nitroglycerin tablets. The FDA does not anticipate a supply problem for these products, as another manufacturer markets FDA-approved sublingual nitroglycerin tablets in the same strengths. The firm with FDA-approved products is able to supply the entire market.  See below for the list of approved and unapproved products.

When is this action going to take effect?

Glenmark Generics Inc and Konec, Inc. have 15 days to respond to the FDA with a discontinuation plan for their products.  They have 90 days from the date of the warning letters to cease manufacturing new products and 180 days to cease further shipment of existing products.  Previously manufactured unapproved affected products may still be found on pharmacy shelves for a short period of time following these deadlines.

Are these products recalled from the pharmacy?

This is not a recall.  Previously manufactured unapproved products affected by this action may still be found on pharmacy shelves for a short period of time.

Why is FDA taking this action?

FDA is taking this action as part of its continuing effort to ensure that drugs marketed in the U.S. have the required FDA approval.  Unapproved sublingual nitroglycerin tablets are not proven safe and effective, and the labeling and quality of these products have not been reviewed by the FDA.  FDA has seen significant quality and efficacy problems with unapproved nitroglycerin products.  The unapproved products may differ from the approved products versions in some respects, such as formulation and labeling.

What effect will FDA’s action have on people who use the unapproved Nitroglycerin Tablets, 0.3 mg, 0.4 mg, and 0.6 mg? Are there alternatives?

Consumers will continue to have access to FDA-approved nitroglycerin sublingual tablets 0.3 mg, 0.4 mg, and 0.6 mg.  Consumers who are using the unapproved products should continue taking their medications and consult a healthcare professional for detailed guidance on treatment options.

How can people tell the difference between FDA-approved and unapproved products?

While the FDA works to ensure that all marketed unapproved drug products obtain approval or are removed from the market, FDA provides various resources that list approved drugs.  Healthcare practitioners and consumers can use Drugs@FDA or the National Drug Code (NDC) Directory, or the Orange Book to determine whether a drug is FDA-approved.  Drugs@FDA contains most FDA-approved drug products.  The NDC Directory is limited to prescription drugs and insulin products.  Search results from the NDC directory include a column marked "Application Number."  FDA-approved products will have an associated NDA (new drug application) or ANDA (abbreviated new drug application) number in this column. Identification of a drug product as "other" indicates that the product has not been FDA-approved (unless there is a data error or the firm did not provide the product's application number).  In the Orange Book, if the product is FDA approved, then the search results will list approved products (note the application number in the "Appl No" column) by dosage form, route, and name of applicant.  If the product is not in the FDA approved list, then the results will state, "No matching records found."

Is it safe to use the unapproved products?

The safety of unapproved drugs is unknown.  Approved sublingual nitroglycerin tablets, 0.3 mg, 0.4 mg, and 0.6 mg have labeling that has been specifically reviewed and approved by FDA, and that reflects the risks, benefits, and safe use of these drugs. This information may not be contained in the labeling of the unapproved products. 

The drug approval process enables FDA to evaluate the drug’s formulation, manufacturing process, and labeling, as well as any changes that occur after approval. 

Should I keep taking my medications?

Consumers should continue taking their medication and speak to their healthcare professionals about replacement prescriptions.

Would there be a shortage on these products?

The approved firm has communicated with FDA that it is able to meet the total market demand with its current production capacity once the unapproved product is no longer on the market.  Since the unapproved firms will be allowed to continue manufacturing for 90 days and distributing for 180 days, this will allow transition time for patients to switch to the approved product.  Before the unapproved product is off the market, hospitals/pharmacies that currently purchase the unapproved product will need to switch and transition to the approved product.  FDA's Drug Shortage Program will update its website to reflect information on the availability of the approved product and will post a  statement from the approved firm that no shortage is anticipated.

What are the approved and unapproved sublingual nitroglycerin tablets, 0.3 mg, 0.4 mg, and 0.6 mg?


List of Approved Nitroglycerin Tablets, 0.3 mg, 0.4 mg, and 0.6 mg
Drug Product Firm NDC #
Nitrostat 0.3 mg Pfizer Pharmaceuticals 65427 - *417
Nitrostat 0.4 mg Pfizer Pharmaceuticals 65427 - *418
Nitrostat 0.6 mg Pfizer Pharmaceuticals 65427 - *419
List of Unapproved Nitroglycerin Tablets, 0.3 mg, 0.4 mg, and 0.6 mg Subject to Warning Letters
Drug Product Firm NDC #
Nitroglycerin Tablets, 0.3 mg Glenmark Generics Inc. 68462-*145
Nitroglycerin Tablets, 0.4 mg Glenmark Generics Inc. 68462-*146
Nitroglycerin Tablets, 0.6 mg Glenmark Generics Inc. 68462-*147
Nitroglycerin Tablets, 0.3 mg Konec, Inc. 62515-*692
Nitroglycerin Tablets, 0.4 mg Konec, Inc. 62515-*718
Nitroglycerin Tablets, 0.6 mg Konec, Inc. 62515-*726