The FDA has issued another alert to consumers about purchasing drugs via internet websites after a number of consumers received drugs containing haloperidol, a powerful anti-psychotic.

Consumers who placed orders for specific drugs – Ambien, Xanax, Lexipro and Ativan – instead received products that contained the haloperidol, a drug used to treat schizophrenia. Reports show that several consumers suffered symptoms such as difficulty in breathing, muscle spasms and muscle stiffness after ingesting the suspect product and sought emergency medical treatment.

The FDA wants to caution consumers about the dangers of ordering prescription drugs online and states that consumers should consult the FDA website before buying medication over the Internet.

Photos of the of the tablets in question and the shipping packages can be seen here.