For 50 years the smoking of marijuana has been a major issue in our country. The idea that marijuana should be considered a medication is a fairly recent addition to the debate. It is a clever addition, however, because “medicines” are good and should be available to those who need them. The citizens of Massachusetts have voted that marijuana is a medicine.

If marijuana is a medicine then we all take on roles. Consumers become patients, doctors become certified agents of the government and sellers become dispensaries. Now we all have to decide what to do. Should you request a prescription; should I, as a family doctor, provide prescriptions, and how should we on Martha’s Vineyard regulate the sale and distribution of marijuana?

I had hoped that when medical marijuana was approved in Massachusetts the provisions of the law would have allowed only limited prescribing of the drug. Unfortunately the Massachusetts law, after naming the serious diseases such as advanced cancer and multiple sclerosis in which a marijuana prescription could be considered, then says that it may also be prescribed for “other conditions as determined in writing by a qualified patient’s physician.”

Marijuana is a drug that many people use for relaxation and enjoyment. Although psychological dependence of marijuana occurs, for the great majority of users it is safe. Marijuana is safer than alcohol and alcohol is legal. Unfortunately marijuana is not legal, and at present those who use, buy and sell more than one ounce of marijuana risk arrest and being charged with a felony.

If other states that have legalized medical marijuana are examples, then the majority of prescriptions for marijuana will not be for patients who have grave medical diseases but for those with diagnoses such as anxiety, chronic insomnia and chronic pain. These patients will for the most part be requesting prescriptions because using marijuana makes them feel better.

Prescribing medications is complicated. To do it as safely as possible doctors must know effective doses and duration of effect so that they can determine the correct initial dose and frequency of use with the original prescription and then can adjust in a logical fashion if the dose requires adjustment. Prescribed marijuana has no reliable dosage. In states with legal medical marijuana, patients are generally advised to adjust the amount of marijuana they purchase to obtain the desired result and to repeat the dose as needed. That is no different than buying marijuana on the street and being told to stop smoking when you feel the way that you want to feel.

Paradoxically medical marijuana may put patients at increased risk of dependence, because it is being prescribed for a symptom or diagnosis that is likely to return when the effect of the marijuana wears off. An example is a patient with chronic neck pain. He feels better when he smokes marijuana. When the marijuana wears off, he feels less good. It makes sense given the indication for its use to smoke another joint. It is the continued and prolonged use that is more likely to lead to dependence as opposed to the person who gets home from work and smokes a joint to relax before supper.

I know that doctors will have differing opinions about prescribing medical marijuana. I suggest caution. Marijuana is not a usual medication. It will be difficult to decide the criteria that will result in a prescription for one patient, but not for another.

Medical marijuana is a new frontier for medicine in Massachusetts. In other states doctors (with and without financial backers) have opened up offices with the express purpose of prescribing medical marijuana. That is not encouraging.

What should we do here in Dukes County? I suggest we try to be the last county in Massachusetts to have a dispensary. See what happens elsewhere first. If Dukes County must have a dispensary it should have only one. We should discourage the establishment of any medical office whose primary purpose would be to prescribe medical marijuana. There should be an all-Island selectmen’s meeting to decide which town will have the dispensary.

Finally, the commonwealth should legalize the purchase of marijuana by adults, and thereby end a misguided medical program.

Dr. Henry Nieder is a family practitioner who has a private practice in Oak Bluffs.