Table 2 Patterns of medical cannabis use and utilization of medical cannabis as a substitute for prescription medications

Aggarwal et al. 2009

When mentioned, mainly smoking.

Not reported

Not reported

From “as needed” to over 10 times daily.

From ½ to 14 g/week.

Not reported

Boehnke et al. 2016

Not reported

Not reported

Not reported

Not reported

45% of respondents reported a 64% reduction in opioid use with medical cannabis use.

Decrease in the number of medications classes used with medical cannabis use (2.38 to 1.81, P < .001).

Bonn-Miller et al. 2014

Not reported

Not reported

Not reported

Participants used 2 to 3 times/day.

They used 6–12 g/week.

Not reported

Bottorff et al. 2011

Primarily smoking.

Smoking:

• convenient

• affordable

• more effective regulation of dosing.

Smoking-related concerns:

• coughing

• breathing difficulties

• fear of lung cancer.

Not reported

Not reported

Bruce et al. 2018

60% of participants preferred smoking;

20% vaporizing;

17% ingestion;

3% topical use.

Not reported

Not reported

Not reported

medical cannabis use reported as:

• alternative to prescription (opioids, anticonvulsants, anti-inflammatories) or OTC medications;

• complementary, with prescription medications;

• a means for tapering off prescription medications.

Brunt et al. 2014

81% inhalation; 19% tea.

Not reported

Not reported

90% of participants used daily.

Mean cumulative dose: 0.65 ± 0.63 g/day [4.5 g/week].

Not reported

Coomber et al. 2003

73% smoking.

Smoking: less amount required than eating or drinking.

Not reported

48% used daily; 24% used 1–3 times/week.

24% used 1–3 joints/day.

Not reported

Corroon et al. 2017

Not reported

Not reported

Not reported

Not reported

Odds of reporting substitution 4.59 (95% CI, 3.87–5.43) times greater among self-identified medical cannabis than among non-medical cannabis users.

Most common classes of drugs substituted: narcotics/opioids (36%), anxiolytics/BZD (14%), and antidepressants (13%).

Cranford et al. 2016

91% reported smoking;

44% eating, drinking, or ingesting;

39% vaping;

11% topical use.

> 50% indicated > 1 mode for past month cannabis use.

Not reported

Not reported

74% of participants used almost daily.

From none to > 1 ounce (14.5% of participants)/month [0 to 6.5 g/week].

Not reported

Crowell 2017

Most frequent mode: 80% smoking; 7% vaporizing; 12% edibles.

Not reported

Not reported

3–4 times/day (41.6–37.9%); 1–2 times/day (38.7–27.1%).

At first visit: 50% of participants had reduced use of pain medication; at visit 2: 62.4%; at visit 3: 60%.

Erkens et al. 2005

70% as tea; 20% smoked.

Not reported

Not reported

1 to 4 times/day.

Not reported

Fanelli et al. 2017

Primarily cannabis tea (smoking cannabis not permitted in Italy).

92% used 22% THC/< 1% CBD Bedrocan.

Not reported

Not reported

From 56.7 ± 45.5 mg/day [0.4 g/week] at treatment initiation; to 67.0 ± 58.8 mg/day [0.5 g/week] at follow-up (98 ± 145 days).

Not reported

Grella et al. 2014

51% used a pipe/water pipe, 47% smoked joints or blunts; 23% used vaporizers; 16.5% edibles; 3.3% oral tincture.

Not reported

Not reported

2.5 ± 2.6 dispensary visits/month.

57% of focus group participants used several times daily.

A common theme among participants was the preference for using medical cannabis instead of prescription medications.

In the previous 30 days, 7% had non-medical use of painkillers, 4% of stimulants, and 8% of tranquillizers.

Grotenhermen & Schnelle 2003

56% inhalation; 17% oral use; 23% used both modes.

Not reported

Not reported

Average doses of natural cannabis products (109 participants): 1.3 ± 0.9 (0.02–3.5) g/day [9.1 g/week].

Not reported

Haroutounian et al. 2016

77% received cannabis cigarettes; 5% received a combination of cigarettes and drops; 10% only drops; 5% only cookies; 3% combination of cookies and drops.

Not reported

Not reported

Monthly prescribed cannabis: 43.2 ± 17.9 g/month

44% of participants on opioid therapy at baseline had discontinued (P < 0.001).

Harris et al. 2000

Mainly smoking.

Not reported

Not reported

65% daily use.

86% used ≥ 2 cigarettes/day.

1 g/day.

Not reported

Hazekamp et al. 2013

63% preferred smoking; 24% vaporizing; 8% food/tincture; 2.4% tea.

Fewer participants had experience with dronabinol 11.3%, nabilone 2.1%, nabiximols 1.1%.

Not reported

Not reported

On average

Times per day: smoking 6.0, vaporizing 5.2, tea 1.9, food/tincture 1.8.

Grams per day: smoking 3, vaporizing 3, tea 2.4, food/tincture 3.4 g.

Not reported

Hoffman et al. 2017

73% smoking; 32% ingestion; 23% vaporizing; 9% topical use.

• Most felt vaporizing healthier than smoking.

• Of those who ingested, most felt it more effective for pain relief than smoking.

Not reported

Not reported

Not reported

Lavie-Ajayi and Shvartzman 2018

Smoking and others (not reported)

Not reported

Unpleasant taste or smell of cannabis.

20–60 g/month

Reduction in side effects of prescription medication.

Medical cannabis use reported as alternative to other medication used for sleeplessness, irritability, restlessness, inability to focus, and depression.

Lintzeris et al. 2018

Inhalation (83.4%)

Not reported

Not reported

Participants used 3 times/day

Not reported

Lucas and Walsh 2017

90% had tried joints, 86% vaporizers, 76% oral/edibles, 16% topical.

Primary methods of use:

38% vaporizing, 25% smoking joints, 14% oral/edibles, 12% waterpipe/bongs, 11% pipes, 1% topicals.

Preferred method:

44% vaporization, 23% edibles.

Not reported

Not reported

88% of participants used at least daily.

Modal: 1–2 g/day [7-14 g/week], with 29% (n = 79) using a larger amount.

63% of participants reported substitution for prescription medication.

The most common form of substitution was for opioids (32%), BZD (16%), and antidepressants (12%).

Lynch et al. 2006

All participants reported smoking some of the time.

30% used both the smoking and oral routes;

7% used primarily the oral route.

Not reported

Not reported

1 to > 6 times/day.

2.5 g/day [17.5g/week].

70% decreased use of other medications that had been causing side effects (NSAIDs, opioids, and antidepressants).

Nunberg et al. 2011 & Reinarman et al. 2011

Not reported

Not reported

Not reported

Not reported

51% reported using cannabis as a substitute for prescription medications.

Ogborne et al. 2000

Mainly smoking.

Smoking:

• enjoyable

• immediate, effective

• less expensive

Eating/drinking:

• “less of a head stone…”

• longer lasting

• no smell

Smoking:

• Respiratory side effects (cough, throat irritation)

Eating/drinking:

• too slow

• less effective

• more difficult to regulate in terms of dose.

70% of participants smoked every day.

They smoked 1 to 10 joints/day.

They used 28 to 56 g/month [6.5-13 g/week].

Not reported

Piper et al. 2017

46% of participants smoked medical cannabis; 23% vaporizing; 14% edibles; 12% tincture.

Vaping: medical cannabis administered with joints was significantly more expensive than via vaporizer.

Smoking:

• not always convenient

• gross

• bad taste.

Vaporizing:

• cumbersome

• too expensive.

Edibles:

• Lack of availability.

Tincture:

• takes too long

• complex dosing.

Not reported

Decrease in prescription medications.

Reiman 2009

Not reported

Not reported

Not reported

Not reported

66% of participants reported having used cannabis as a substitute for prescription drugs.

Reiman et al. 2017

50% smoking; 30% vaporizing; 10% edibles.

Not reported

Not reported

Not reported

97% of participants decreased the amount of opioids they consume when they also use cannabis.

96% do not need to take as much of their nonopioid-based pain medication when they use cannabis.

Reinarman et al. 2011

86% smoking; 24% orally; 22% vaporizing.

Not reported

Not reported

67% daily use; 53% use 1–2 times per day.

≤3 grams (40%) to ≥7 grams (23%) per week.

50.9% of participants reported use of medical cannabis to substitute prescription medication.

Sagy et al. 2019

Smoking, oil

Not reported

Not reported

From 670 to 1000 mg/day

After 6 months of medical cannabis therapy, a substantial proportion of participants stopped or decreased the dosage of other medical therapies.

Schnelle et al. 1999

49% inhalation; 14% eating, drinking; 36% used both the oral and inhalation routes

4% used dronabinol.

Not reported

Not reported

Not reported

Not reported

Sexton et al. 2016

84% inhalation: 32% pipes, 19% bongs, 16.5% joints/blunts, 16% vaporizer; 8% oral (edibles, tinctures, capsules); 6% concentrates (oil, keif, hash); 0.6% topical; 0.5% fresh juice.

Not reported

Not reported

61% reported using 1–5 hits per smoking session, 21.3% reported 6–10 hits, 18% reported >10 hits/session.

25% reported using less than 1 once/day; 1–4 times/day (47.6%); 5–10 times/day (14.9%), and 12.2% reported using all day, every day.

Reported use (g/week):

< 1 (12.3%); 1–2 (20.3%); 3–5 (31.8%); 7 (26.1%); 28 (6%), > 28 (3.4%).

60% reported substitute medical cannabis for prescription drugs, 25% for pain medications, including opiates.

Shah et al. 2017

54% smoking; 29% tablets; 8% edibles.

Not reported

Not reported

62.5% of medical cannabis users endorsed daily use, 21% weekly use.

Cannabis use was not associated with a significantly lower morphine equivalence level for participants using prescription opioids.

Shiplo et al. 2016

53% of participants preferred vapourizing; 47% smoking a joint.

Among those reporting multiple modes: 25% eating in food, 23% drinking.

• Time to onset of effect.

• Ability to find correct dose.

• Smoking lower cost and more accessible.

• Eating/drinking had more durable effect.

• Harm from smoking.

Eating in foods:

• producing the worst high

• most stigma

• hardest to find a correct dose.

Almost every day: 77%, > once a day: 82%.

1.8 ± 1.6 g/day [12.6 g/week].

Not reported

Ste-Marie et al. 2012

Out of the 59 medical cannabis users: 80% smoked herbal cannabis; 24% used prescription cannabinoids; 3% used both.

Not reported

Not reported

72% used < 1 g/day [< 7 g/week].

Not reported

Ste-Marie et al. 2016

86% smoking; 21% vaporizing; 18% ingestion; 4% topical.

Not reported

Not reported

For the 22 patients who recorded amounts used, most reported ≤ 1.5 g/day [≤ 10.5g/week].

Not reported

Swift et al. 2005

91% smoked.

74% considered smoking the most helpful route.

Smoking:

• Instant effect.

• Ease of titration.

• Cost-effectiveness.

Edibles:

• Healthier

• Tasty when cooked in a recipe

• Less obvious

• Slow onset and long-lasting effects.

Smoking:

• Detrimental to respiratory function (and health)

Edibles:

• Availability of recipes

• Difficulties with titration

• expensive and ineffective for rapid relief.

75% used at least weekly, 59% used almost daily, 22% used “as required.”

62% of participants claimed they decreased or discontinued their use of other medicines with medical cannabis use.

Troutt & DiDonato 2015

67% inhalation: ~ 42% smoking, ~ 25% vaporizing; ~ 27% edibles; ~ 4% tincture; ~ 2% oils.

Not reported

Not reported

84% used several times per week or more, 61% used daily.

78% used < 14 g/month [3.2 g/week].

90% of chronic pain, 81% of arthritis, 94% of fibromyalgia, and 84% of osteoarthritis patients report less frequent use of other medications.

Walsh et al. 2013

57% smoking; 43% vaporizing; 28% orally.

Not reported

Not reported

53% used 2–3 times/day, 42 used ≥ 4 times/day.

45% used >14 g/week.

Ware et al. 2003

Among users for pain:

81% joint, 47% joint with tobacco, 34% pipe, 16% water pipe; 9% orally.

Not reported

Not reported

53% used ≤ 4 puffs/dosing interval, 25% smoked a whole cannabis cigarette, 12% smoked ≥ 1 joint.

22% of these participants used cannabis > 1 time/day, 16% used daily, 25% used weekly and 28% rarely used medical cannabis.

Not reported

Webb & Webb 2014

Not reported

Not reported

Not reported

Not reported

6% wrote brief notes relating how cannabis helped them to decrease or to discontinue other medications.

Zaller et al. 2015

74% smoking; 16.5% vaporizing; 7% orally.

Not reported

Not reported

60.5% used ≥ 3 times/day.

48.5% used 3–8 g/day, 34.5% used > 8 g/day [21–56 g/week].

55% indicated they had used cannabis as a substitute for prescription medications.