The San Francisco Department of Public Health confirmed that two people fell critically ill and are still hospitalized after drinking an herbal toxic tea bought in San Francisco's Chinatown.

According to the report from USA Today, the two patients, a woman in her 50s and a man in his 30s, became weak and in need of medical assistance an hour after drinking an herbal toxic tea purchased at Sun Wing Wo Trading Company.

The two incidences occurred separately in February and March. Further investigations revealed that the cause of the tea poisoning is a plant-based toxin known as aconite. While commonly used as an Asian remedy for pains, bruises and other conditions, aconite -- also called monkshood, helmet flower, wolfsbane, chuanwu, caowu and fuzi -- can be highly toxic. However, despite the high toxicity of its raw flower, the plant can be consumed when properly processed.

"Anyone who has purchased tea from this location should not consume it and should throw it away immediately," said Dr. Tomás Aragón, health officer for the city, in a report from SF Gate. "Aconite poisoning attacks the heart and can be lethal."

So far, there is no known antidote for aconite poisoning. Both patients experienced weakness, followed-by life-threatening abnormal heart rhythms that required resuscitation. Other symptoms of aconite poisoning include numbness or tingling in the face, mouth or lips, low blood pressure, palpitations, chest pains, paralysis, diarrhea and nausea.

After making the link between the herbal tea and poisoning of two individuals, inspectors from the city health department quickly removed the herbal tea in question. The connection was made after the case was referred to the California Poison Control System and San Francsico General Hospital.

The health department is also working closely with the shop owners to identify the source of the tea contamination and prevent further spread.

Health officials warned everyone who may have bought the product to stop drinking it, despite having no reaction after drinking the tea. Additionally, anyone who experienced symptoms of aconite poisoning should immediately call 911 or go to the nearest hospital.