BROWNSVILLE – A couple caught smuggling a dangerous drug through the border are facing federal charges.

Maria Esperanza Garcia and Hector Fuentes-Gutierrez were arrested after entering the country with undeclared prescription medicine.

The amount they were carrying exceeded personal use.

It happened August 18 as they re-entered the country from Mexico via the Gateway International Bridge.

According to the criminal complaint, when they reached inspection they declined bringing back any medication.

Nervousness in Garcia's responses led officers to refer the couple to secondary inspection where 201 bottles of Tramadol were discovered – a total of 20,100 pills.

Pharmacist and owner of Cantu Pharmacy Nario Cantu explained the drug is a pain reliever but can be dangerous.

"You can end up in the hospital, and there's a potential, as I mentioned, if it's mixed with other medications that cause respiratory depression there could be an opportunity or chance of death," he says.

To report any possible interactions, the Poison Control Hotline is 1-800-222-1222.

Tramadol was classified as a Schedule IV controlled substance by the Drug Enforcement Administration, because it can be highly addictive and there's a high risk for dependency.

Court documents state the couple admitted they planned to sell the drugs for profit.

They were released on bond, but are facing federal criminal charges for possessing with the intention to distribute a controlled substance.

Arraignment is scheduled September 12.