FDA has recently issued a warning to patients and doctors who use at-home or in-office medical devices to monitor levels of the blood thinner warfarin that certain test strips used with the devices may provide inaccurate results and should not be relied upon to adjust the drug dosage.

In December, medical product distributor Terrific Care/Medex Supply LLC issued a voluntary recall of certain Roche Diagnostics test strip lots used with the company’s CoaguChek test meters. FDA classified the action as a Class I recall, the most serious type of recall, which means use of the devices may cause serious injuries or death. The recall is also related to a November 2018 recall by Roche Diagnostics, the manufacturer of CoaguChek meters and test strips.

The recall initiated by Roche, which is still in effect, involved more than 1.1 million packages of CoaguChek XS PT test strips that were distributed nationwide from January 12, 2018, to October 29, 2018. The CoaguChek XS PT test strips announced in the new recall were manufactured by Roche, but distributed by Terrific Care/Medex Supply. The newly recalled test strips include catalog numbers that were not included in the preceding Roche recall because the strips were not labeled or authorized for sale in the United States and were only distributed by Roche Diagnostics outside the country. Terrific Care/Medex Supply purchased the Roche test strips from an unknown source and imported and sold them in the United States.

“Monitoring warfarin dosing is a critical part of using the drug properly to prevent and treat blood clots. Using faulty strips can lead to errors in medication dosage that could cause serious harm or death in some patients,” says FDA Commissioner Scott Gottlieb, MD. “That’s why it’s so concerning that this distributor continued to sell these test strips in the United States even though domestic sales had been stopped due to safety concerns. To reduce risks to patients, we’re warning healthcare providers and the public about the dangers associated with this product.

“Distributing products that are not labeled or authorized for sale in the United States raises significant concerns for us in view of the serious safety issues with these test strip devices, and our work on this matter is not finished,” Gottlieb adds. “Our top priority is the immediate safety of patients, and we’re taking steps to ensure the products that this company distributed are removed from the market.”

As with the previous recall, FDA is warning patients and healthcare professionals that they should not rely on test meters to monitor warfarin levels if they’re using test strips affected by the recall. Instead, patients they should have blood drawn from a vein and have their levels measured by a laboratory test or use an alternative meter and appropriate test strips.

FDA’s previous warning concerning CoaguChek XS PT test strips was based on reports submitted to the agency by Roche Diagnostics indicating that the test strips may provide results that are higher than the actual international normalized ratio (INR). As a result of incorrect INR results, some patients could be prescribed an insufficient warfarin dose or instructed to interrupt warfarin use, which could in turn increase the risk for dangerous blood clots.

Incorrect INR results are of particular concern for individuals at an increased risk of blood clots, including those with mechanical heart valves, those with atrial fibrillation (irregular heartbeat) who are at a high risk of stroke, or those who had a recent blood clot. Problems with the CoaguChek XS PT test strips are not likely to be evident to the patient.

The test strips are used with the Roche’s CoaguChek XS plus, CoaguChek XS Pro, CoaguChek XS professional, CoaguChek XS PST, and CoaguChek Vantus test meters.

Patients and healthcare providers who are using CoaguChek meters should immediately stop using test strips purchased from Terrific Care/Medex Supply and use an alternative test method.

All healthcare providers, patients, and caregivers are strongly encouraged to report INR test meter problems directly to FDA through MedWatch, the agency’s voluntary reporting program. Problems should be reported whenever one suspects that there may be an issue with an INR test meter, such as a malfunction or incorrect result, or that the meter caused or contributed to a serious injury or death.


1. Terrific Care LLC/Medex Supply Dist Inc Issues Nationwide Recall of CoaguChek Test Strips [recall notice, online]. Silver Spring, Md: FDA, 2018. Available at: www.fda.gov/safety/recalls/ucm628976.htm. Accessed February 21, 2019.