On July 15, 2020, FDA announced the final decision of the Commissioner of Food and Drugs, that Vasodilan containing isoxsuprine hydrochloride lacked substantial evidence, consisting of adequate and well-controlled studies, to be effective for specific indications. Vasodilan containing isoxsuprine hydrochloride was part of the Drug Efficacy Study Implementation process. FDA notified manufacturers and labelers of the products (see list below) on Aug. 9. 2021, to stop distributing their isoxsuprine hydrochloride drug products. As of Oct. 13, 2021, all the companies agreed to cease distribution of the unapproved isoxsuprine HCl drugs. 

FDA considers isoxsuprine hydrochloride drug products unapproved new drugs that cannot be distributed in interstate commerce without a new drug application approved by FDA. The distribution of any unapproved isoxsuprine hydrochloride drug products, not limited to the drug products listed below, is considered unlawful and subject to enforcement action.

Unapproved Isoxsuprine Hydrochloride Drug Products and NDCs 

	NDC	Product Name and Strength
1	42582-101	Isoxsuprine hydrochloride 10 mg tablet
2	42582-201	Isoxsuprine hydrochloride 20 mg tablet
3	51293-605	Isoxsuprine hydrochloride 20 mg tablet
4	51293-606	Isoxsuprine hydrochloride 10 mg tablet
5	66576-201	Isoxsuprine hydrochloride 20 mg tablet
6	66576-101	Isoxsuprine hydrochloride 10 mg tablet
7	61971-065	Isoxsuprine hydrochloride 20 mg tablet
8	42582-200	Isoxsuprine hydrochloride 20 mg tablet
9	42582-100	Isoxsuprine hydrochloride 10 mg tablet
10	63549-919	Isoxsuprine hydrochloride 20 mg tablet

For more information:    

• FDA’s Drug Efficacy Study Implementation