The S.C. House passed a bill Wednesday that would provide a narrow exception for a type of medical marijuana extract that offers hope for those with severe forms of epilepsy.

The bill, H. 4803, sponsored by Rep. Jenny Horne, R-Summerville, passed 90-24 in a chamber normally dominated by conservative measures and rhetoric. It is similar to a measure that passed the S.C. Senate with one notable exception: it allows for patients who qualify to possess cannabidiol oil (CBD), a marijuana extract that many have found helps with epilepsy and other conditions.

The Senate bill calls for clinical trials at Medical University of South Carolina and other hospitals that treat severe forms of epilepsy. But state police had raised concerns with any broader measures.

Horne said that even though state law enforcement objects, CBD oil offers hope to those who need the medicine. "It can be a miracle drug," she said.

Jill Swing, the mother of 6-year-old Mary Louise Swing, who has severe epilepsy, said the House bill has the potential to help her daughter. But she worries that if her daughter were one of the lucky few to be accepted into a clinical trial, she could receive a placebo instead of the drug.

Thousands more need the oil than clinical trials could treat, she said.

"I'm far more optimistic than I was a year ago," Swing said of the measure. House and Senate leaders will have to agree on the bills' differences for the measure to move forward.

Federal law bans all forms of medical marijuana. While federal law enforcement has decided largely not to prosecute recreational and medical uses of marijuana, it can create a difficult conundrum for a parent. If Horne's bill passes, purchasing it would still be illegal under federal law.

Horne said she hopes Congress resolves the issue.

"To be determined," Swing said of whether she would seek to access the drug if Horne's bill passes.

Reach Jeremy Borden at 708-5837.