The first drug to be approved by the Food and Drug Administration (FDA) to treat marijuana-induced colitis in adults was approved on Tuesday.

In a move that could pave the way for the use of marijuana-derived oils for the treatment of other chronic diseases, the FDA approved the product as a “tumour-killing” agent.

The agency says the oil, which contains THC (the active ingredient in marijuana) but also contains cannabidiol (CBD), the active ingredient of the marijuana plant, is an “unusually effective” and “safe” treatment for chronic pain.

While there is no evidence that THC alone can cure or reverse colitis, its combination with CBD could offer a promising new treatment option.

According to the FDA, the drug is safe for use in adults aged 18 and older.

The FDA did not specify when the approval would take effect.

The oil can be used to treat colitis by either inhaling or sublingually, and is the only drug approved by Congress to treat the condition.

While it does not cure colitis outright, the product can be given to patients who have suffered from chronic pain for a prolonged period of time.

This is because the FDA said it is more likely that the oil would help a person with colitis than would other therapies.

However, the agency did note that some patients may not respond to the drug.

“We also note that patients who respond to cannabinoids do not experience significant improvement over placebo,” the agency wrote.

“Therefore, in this instance, the decision was made to reject the application for approval.”

The FDA said its decision is “not based on the scientific evidence” and that it will wait for further clinical studies before making a decision.

The drug is expected to become available to the public in July.