Meldonium, a cardiac drug that was recently banned by the World Anti-Doping Agency (WADA), can last in the body for several months, the drug's manufacturer, Grindeks, said Monday.

The fact that the drug can remain in the body months after it was initially taken can be problematic for many athletes, especially with the 2016 Rio de Janeiro Olympics coming up this summer. Grindeks, a Latvian company, recently provided more information on meldonium (Mildronate).

The company stated that even though the drug has a half-life of about four to six hours, "its terminal elimination from the body may last for several months" based on variables such as the dosage amount or length of treatment.

The drug recently gained a lot of attention after Russia's top female tennis player, Maria Sharapova, failed a drug test during the Australian Open earlier this year. The five-time Grand Slam champion, who is currently banned until the International Tennis Federation (ITF) finishes its investigation, said she has been taking meldonium for more than 10 years for multiple health issues and did not realize that it had been banned.

At least 16 Russian athletes, including an Olympic speed skater and several track and field competitors, have tested positive for the drug.

The chemist who created the drug defended its use in an interview with CNN.

"Most athletes should be on this drug," Ivar Kalvins said. "It protects the heart."

Kalvins claimed that Russia, back in the day, had conducted studies that examined the medical benefits from taking meldonium in athletes. The results from these studies, however, have never been released. Many cardiologists have argued that without this data, everything that Kalvins is claiming cannot be taken seriously.

Meldonium, which treats cardiovascular conditions such as angina, has not been approved by the U.S. Food and Drug Administration (FDA).

The WADA decided to ban the drug after finding more and more evidence that the drug can boost athletes' performance.

"Meldonium was added [to the Prohibited List] because of evidence of its use by athletes with the intention of enhancing performance," the WADA said in its statement regarding Sharapova's case.

WADA spokesperson Ben Nichols explained the process that the agency goes through when deciding whether or not a drug should be banned.

"The list is updated annually and with a full and thorough consultation period with experts and stakeholders over the course of six months," Nichols said. "A substance or method may be added to the list [if] it meets two of the following three criteria: enhances performance, detrimental to the health of the athlete [and] contrary to the spirit of sport."

Since the ban of the drug, there have been at least 100 positive drug tests related to meldonium.