BOSTON — As the state Senate begins debate Wednesday on a more than $36 billion state budget, medical marijuana advocates are objecting to proposed amendments they say will impose new taxes on low-income, chronically ill patients and further delay opening of state-licensed dispensaries.

Matthew Allen, executive director of the Massachusetts Patient Advocacy Alliance, said his group is working to defeat the amendments, including proposals to subject medical marijuana and marijuana-infused brownies, cookies and other “edibles” to the state’s 6.25 percent sales tax.

“To tax sick and suffering patients is just wrong,” Allen said Tuesday. “By their very nature, medical marijuana patients tend to be lower income people because that’s the nature of serious and chronic illness.”

Some patients may have to choose between paying for medicine or paying for food or rent, he said.

Most of the proposed amendments have been filed by Sen. Brian Joyce, D-Milton. Joyce, who did not respond to requests for comment, has also filed a budget amendment assessing a 4 percent surcharge on revenues generated by dispensaries, which had been expected to open this summer to grow marijuana in large quantities and sell it to qualified patients.

He proposes using those surcharge revenues — as well as sales tax profits from medical marijuana sales — toward a new state fund to support substance abuse treatment.

In other amendments, Joyce wants to create a new, three-member state “Cannabis Commission” to license and regulate dispensaries while Senate Minority Leader Bruce Tarr, R-Gloucester, wants to require the state inspector general to investigate the state’s ongoing medical marijuana licensing process.

The state Department of Public Health is currently vetting 20 companies already awarded “provisional” dispensary licenses, but critics say the process has been arbitrary and flawed. State law allows the department to award up to 35 dispensary licenses

Joyce’s proposal to tax medical marijuana specifically states that marijuana should not be considered “medicine” for sales tax purposes. Other states have similar arrangements.

It comes as the state Department of Revenue has not determined whether medical marijuana will be exempt from the state sales tax like prescription drugs. Department spokeswoman Maryann Merigan says the department has not issued any guidance on the matter in the absence of legislation.

Matt Simon, New England Political Director for the Marijuana Policy Project, suggested if state lawmakers are serious about generating new revenue from marijuana sales, they should just legalize marijuana for recreational use by adults.

Fifteen states and Washington, D.C., have medical marijuana programs that allow for dispensaries. Of those, eleven subject medical marijuana to some form of sales or gross receipts tax, according to data from the Marijuana Policy Project. In New England, Connecticut, Rhode Island and Maine all subject medical marijuana to the state sales tax; New Hampshire does not have a sales tax and Vermont does not tax the drug.

Qualified patients in Massachusetts are currently allowed to grow small quantities of marijuana, or designate a “caregiver” to provide it for them. Massachusetts voters approved use of marijuana for treatment of cancer and other chronic ailments in 2012.