Marinol Versus Medical Marijuana: A Comparison

Marinol versus Natural Medical Marijuana

Marinol (dronabinol) is a US FDA-approved synthetic cannabinoid. It is often marketed as a legal pharmaceutical alternative to natural cannabis. But how does it compare to natural cannabis?

Marinol is manufactured as a gelatin capsule containing synthetic delta-9-tetrahydrocannabinol (THC) in sesame oil. It is taken orally and is available in 2.5mg, 5mg, and/or 10mg dosages. Marinol may be prescribed for the treatment of cachexia (weight loss) in patients with AIDS and for the treatment of nausea and vomiting associated with cancer chemotherapy in patients who have failed to respond adequately to conventional antiemetic treatments.

Despite FDA approval, Marinol typically provides only limited relief to select patients, particularly when compared to natural cannabis and its cannabinoids. Why?

Marinol Lacks Several of the Therapeutic Compounds Available in Natural Cannabis

Natural compounds in cannabis known as cannabinoids are responsible for their numerous therapeutic benefits. The best-known of these are THC and CBD. But there are many others, all with varying degrees of clinical effect and importance. Scientists have identified 66 naturally occurring cannabinoids.

The active ingredient in Marinol, synthetic delta-9-tetrahydrocannabinol (THC), is an analog of just one such compound, THC. However, several other cannabinoids in natural cannabis, in addition to naturally occurring terpenoids (oils) and flavonoids (phenols), have been clinically demonstrated to provide therapeutic benefits. Many patients favor natural cannabis over Marinol because it includes these other therapeutically active cannabinoids, and they get better relief.

For example, cannabidiol (CBD) is a non-psychoactive cannabinoid that has been clinically demonstrated to have analgesic, antispasmodic, anxiolytic, antipsychotic, antinausea, and anti-inflammatory properties. Animal and human studies have shown CBD to possess anti-convulsant properties, particularly in the treatment of epilepsy. Natural extracts of CBD, when administered in combination with THC, significantly reduce pain, spasticity, and other symptoms in multiple sclerosis (MS) patients unresponsive to standard treatment medications. Clinical studies also demonstrate CBD to be neuroprotective against glutamate neurotoxicity (i.e., stroke), cerebral infarction (localized cell death in the brain), and ethanol-induced neurotoxicity, with CBD being more protective against glutamate neurotoxicity than either ascorbate (vitamin C) or alpha-tocopherol (vitamin E). Clinical trials have also shown CBD to possess anti-tumoral properties, inhibiting the growth of glioma (brain tumor) cells in a dose-dependent manner and selectively inducing apoptosis (programmed cell death) in malignant cells.

Additional cannabinoids possessing clinically demonstrated therapeutic properties include cannabinol (anticonvulsant, sleep health, and anti-inflammatory activity); cannabichromine (anti-inflammatory and antidepressant activity); and cannabigerol (anti-tumoral and analgesic activity). Natural cannabis’ essential oil components (terpenoids) exhibit anti-inflammatory properties and its flavonoids possess antioxidant activity. Emerging clinical evidence indicates that cannabinoids may slow disease progression in certain autoimmune and neurologic diseases, including multiple sclerosis (MS), Amyotrophic Lateral Sclerosis (Lou Gehrig’s disease), and Huntington’s Disease.

Clinical data indicate that the synergism of these compounds is more efficacious than the administration of synthetic THC alone. For example, McPartland and Russo write: “Good evidence shows that secondary compounds in cannabis may enhance beneficial effects of THC. Other cannabinoid and non-cannabinoid compounds in herbal cannabis … may reduce THC-induced anxiety, cholinergic deficits, and immunosuppression. Cannabis terpenoids and flavonoids may also increase cerebral blood flow, enhance cortical activity, kill respiratory pathogens, and provide anti-inflammatory activity.” In an in vitro model of epilepsy, natural cannabis extracts performed better than THC alone. In human trials, patients suffering from multiple sclerosis experienced greater symptomatic relief from sublingual natural cannabis extracts than from the administration of oral THC. In 2005, Health Canada approved the oral spray Sativex — which contains precise ratios of the natural cannabinoid extracts THC and CBD, among other compounds — for prescription use for MS-related symptoms.

In summary, the many natural elements present in whole-plant cannabis offer better relief for most patients with fewer side effects than isolated or synthesized THC alone.

Marinol is More Psychoactive Than Natural Cannabis

Patients prescribed Marinol frequently report that its psychoactive effects are far greater than those of natural cannabis. Marinol’s adverse effects include feeling “high,” drowsiness, dizziness, confusion, anxiety, changes in mood, muddled thinking, perceptual difficulties, coordination impairment, irritability, and depression. These psychoactive effects may last four to six hours. About one-third of patients prescribed Marinol report experiencing one or some of these adverse effects.

Marinol is More Expensive Than Natural Cannabis

Synthetic THC is a costly and difficult compound to manufacture. Much of this cost is passed on to the patient consumer, particularly if the full cost of Marinol (approximately $200 to $800 per month, depending on the dosage) is borne out of pocket. Patients, particularly those with chronic conditions, often report that Marinol’s market cost limits their use of the drug. Doctors also report that Marinol’s high cost dissuades them from prescribing it to patients. In one survey of HIV/AIDS specialists, among respondents who had never prescribed Marinol to their patients, 33 percent cited the high cost of the drug as the reason. Natural cannabis remains far less costly for patients than oral synthetic THC.

Patients Ultimately Prefer Natural Cannabis to Marinol

In the 1970s and 1980s, several states conducted patient trials of natural cannabis’ effectiveness as an anti-emetic in cancer patients unresponsive to conventional therapies. Some state protocols allowed patients to choose between inhaled cannabis and synthetic THC. In those studies that compared natural cannabis to dronabinol, inhaled cannabis was equal to or better than the oral administration of synthetic THC.

For example, researchers at the Tennessee Board of Pharmacy found a “23 percent higher success rate among those patients smoking than among those patients administered THC capsules” in the treatment of nausea and/or vomiting associated with cancer chemotherapy. Researchers in New Mexico observed similar findings. “When the routes of [drug] administration were analyzed separately, it was found that inhalation was far superior to ingestion: 90.39 percent of the patients in the group that inhaled the marijuana showed improvement while only 59.65 percent of the patients in the group that orally ingested the delta-9-THC showed improvement,” they concluded. Researchers at the California Board of Pharmacy found that inhaled cannabis and oral THC produced similar results in patients. However, physicians still rated natural cannabis as slightly more effective than oral THC as an anti-emetic. A 1988 New York State pilot study comparing inhaled cannabis to oral THC in cancer chemotherapy patients who were unresponsive to standard antiemetic agents found: “Twenty-nine percent of patients who failed oral THC responded to the cigarette form. … Our results demonstrate that inhalation of marijuana is an effective therapy for the treatment of nausea and vomiting due to cancer chemotherapy.”

Today, several patient populations use natural cannabis and its cannabinoids in large numbers despite the availability of Marinol. A 2005 British survey of more than 500 HIV/AIDS patients found that one-third of respondents use natural cannabis for symptomatic relief, with more than 90 percent of them reporting that it improves their appetite, muscle pain, and other symptoms. A previous US survey found that approximately one out of four patients with HIV had used natural cannabis medicinally in the past month.

Cannabis use is also prevalent among patients with neurologic disorders. Nearly four out of ten Dutch patients with prescriptions for “medical grade cannabis” (cannabis provided by Dutch pharmacies with a standardized THC content of 10.2 percent) use it to treat MS or spinal cord injuries, according to survey data published in 2005 in the journal Neurology. Perceived efficacy is greater among respondents who inhale cannabis versus those who ingest it orally, the study found.

A 2002 British survey of MS patients found that 43 percent of respondents used natural cannabis therapeutically, with about half admitting they used it regularly. Seventy-six percent said they would do so if cannabis were legal. A Canadian survey of MS patients found that 96 percent of respondents were “aware cannabis was potentially therapeutically useful for MS and most (72 percent) supported [its] legalization for medicinal purposes.” Sixteen percent of respondents answered that they use natural cannabis for medical purposes to treat symptoms of anxiety/depression, spasticity, and chronic pain.

A more recent Canadian survey published in Neurology reported that 14 percent of MS patients and 21 percent of respondents with epilepsy had used medical cannabis in the past year. Among epileptics, twenty-four percent of respondents said that they believed that cannabis was an effective therapy for the disease. A 2002 survey of patients with Parkinson’s Disease (PD) found that 25 percent of respondents had tried cannabis, with nearly half of those saying that it provided them symptomatic relief.

Conclusion

Oral synthetic THC, legally available by prescription as Marinol, often provides only limited relief to a select group of patients, particularly when compared to natural cannabis and its cannabinoids. Patients often experience minimal relief from Marinol and many experience unwanted side effects. In addition, many physicians are hesitant to prescribe the drug, and some patients are unable to afford it. Despite Marinol’s legality, many patient populations continue to risk arrest and criminal prosecution to use natural cannabis medically, and most report experiencing greater therapeutic relief from it.

Thankfully, patients in Virginia now have legal access to high-quality natural cannabis. By obtaining a medical certification, patients can benefit from the improved relief of these natural products. The specialized cannabis physicians at ReThink-Rx bring decades of experience and education to help you understand the principles and strategies for successful cannabis therapy.

The active ingredient in Marinol is a synthetic analog of only one of the compounds in cannabis. By prescribing products like Marinol, patients are unnecessarily burdened to use a synthetic substitute that lacks much of the therapeutic efficacy of natural whole-plant cannabis and its cannabinoids.