Drugmaker Pfizer Inc. issued a recall Thursday for two lots of the migraine pill, Relpax, on account of potential bacteria contamination. The specific lots are 40 mg pills and are designated AR5407 and CD4565.

The bacteria in question come from the genera pseudomonas and burkholderia. Once they enter the bloodstream, they are capable of causing serious, life-threatening infections, or temporary gastrointestinal distress without infection. Pfizer notes that the risk of these effects is low for the general population is low, but patients with compromised immune systems, cystic fibrosis, and chronic granulomatous disease could potentially face severe and dangerous events.

To date, Pfizer has not received reports of adverse effects related to contaminated Relpax. The affected lots were distributed nationwide to wholesalers, retailers, hospitals, and healthcare providers in the U.S and Puerto Rico between June and July 2019.

Individuals currently taking Relpax are encouraged to consult with their healthcare providers or pharmacy to determine whether their pills are from the affected lots.

Patients with the affected lots should return them to their pharmacy or contact Stericycle Inc. at 877-225-9750 for instructions on how to return or receive reimbursement for the product.

Adverse reactions caused by this product should be reported to the FDA's MedWatch Adverse Event Reporting program either online, by regular mail, or by fax. To mail or fax, download the necessary form or call 1-800-332-1088 to request it, then complete and return to the address on the pre-addressed form, or submit by fax to 1-800-FDA-0178

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A Pfizer sign hangs on the outside of their headquarters in New York City. Photo by Mario Tama/Getty Images