The drug Maria Sharapova tested positive for is intended for short-term use

The ITF announced on Monday that Maria Sharapova failed a drug test at the Australian Open for use of meldonium, a product that was put on the World Anti-Doping Agency's list of banned substances beginning Jan. 1, 2016. Now the maker of the drug is suggesting Sharapova's usage of their product was atypical.

Grindeks, the Latvian company which manufactures meldonium told the Associated Press that a common course of the drug is 4-6 weeks. In her press conference Monday, Sharapova said she had been taking the drug since 2006. Grindeks added that it's not uncommon for patients to take several treatment courses, but that a physician needs to monitor a patient to determine whether a longer course is needed, or safe.

The Latvian company initially said its drug can increase work capacity in healthy people, but backed away from those statements Tuesday by telling the AP that they did not believe meldonium would enhance an athlete's performance. On the contrary, Grindeks said their product would likely hinder an athlete's ability by slowing the body's ability to break down fatty acids.

An over-the-counter drug in several Eastern European countries, meldonium has not been approved by the FDA for sale in the United States. It was recently added to the World Anti-Doping Agency's list of banned substances, and notification of its addition was sent to athletes in September of 2015. Sharapova claims she saw an email announcing meldonium's status as a banned substance in December, but did not read it. Grindeks declined to comment on whether Sharapova's claimed medical reasons for taking the drug are consistent with complications it was designed to treat.

Sharapova's announcement rocked the tennis world on Monday and immediately companies sought to distance themselves from the former women's No. 1. Sponsors Nike, TAG Heuer and Porsche have all either ended or suspended advertising campaigns with Sharapova, which helped contribute to her $30 million in total earnings in 2015.

A combination of injuries and the drug controversy leave Sharapova's career up in the air. The 28-year-old is fast approaching the age at which tennis players typically retire, but she joked about that possibility in her press conference on Monday. She is likely facing a ban for the positive test in Australia, which could impact this possibility. These bans vary in length from several months to as many as four years, depending on determining factors the ITF takes into account, such as intent to cheat.