Anxiety Animal studies

Musty et al. (1985) found CBD increased licking for water in the lick suppression test in a dose related fashion (mg/kg). Equivalent effects were found with the classic anxiolytic drug diazepam. In an effort to find more potent effects, they tested two analogs, 2-pinyl-5-dimethylheptyl resorcinol (PR-DMH) and Mono-methyl canna-bidiol (ME-CBD-2). ME-CBD-2 had anxiolytic activity, but was less potent than CBD, while PR-DMH had no anxiolytic properities. Of the two active compounds, both were less potent than diazepam.

In another series of experiments, Musty (1984) found that CBD inhibited the development of stress-induced ulcers in rats as compared with diazepam, which produced equivalent reduction in the number of stress-induced ulcers. Guimaraes et al. (1990) tested rats in the elevated plus maze. In the first test, rats are placed in a plus shaped maze which is elevated off the floor. Two of the maze arms are enclosed with walls and two are not. Time spent in the enclosed arms is taken as

Table 2.2 Human studies on the analgesic effects of cannabis and cannabinoids

Reference

Subjects

Drug and dose

Type of study

Results

Noyes et al. (I975a) Noyes et al. (I975b) Raft et al. (I977)

Lindstrom et al. (1987) Cited by Consroe and

Sandyk (1992) Maurer et al. (1990)

Grinspoon and Bakalar (I993)

10 patients with cancer pain

36 patients with cancer pain

10 patients undergoing extraction of impacted molar teeth

2 patients with painful muscle spasms (1 spinal cord injury, 1 MS) 56 patients with postoperative pain

10 patients with chronic neuropathic pain

1 patient with spinal cord injury

3 patients with various severe acute/chronic pain not controlled with opiates. 1 patient with migraine

Oral THC 5, 10, 15, 20 mg in random order

Oral THC 10 and 20 mg, oral codeine 60 and 120 mg

IV THC 0.22 mg/kg and 0.44 mg/kv, IV diazepam 0.157 mg/kg

Cannabis

IM levonantradol 1.5-3 mg

Oral cannabidiol 450 mg/day in divided doses

Oral THC 5 mg, oral codeine 50 mg, each given 18 times over 5 months

Smoking cannabis

Double blind, placebo controlled

Double blind, placebo controlled

Double blind, placebo controlled

Open clinical report

Double blind, placebo controlled

Double blind, placebo controlled

Anecdotal reports

Significant pain relief with 15 and 20 mg THC compared to placebo. Drowsiness and mental clouding common THC 20 mg and codeine 120 mg gave equivalent and significant pain relief compared with placebo. THC caused sedation and mental clouding No analgesic effects of THC detected. Higher dose of THC was rated as least effective, diazepam most effective. 6 subjects preferred placebo to THC, 4 preferred low dose THC to placebo

Relief from pain and muscle spasms

Significant pain relief with both doses of levonantradol compared with placebo Drowsiness common with levonantradol No analgesic effect of cannabidiol compared to placebo. Sedation with cannabidol in 7 patients

THC and codeine alleviated pain to a similar degree: THC also relieved spasticity

Pain relief reported in all cases allowing reduction in other analgesics; no "high" reported

British Medical Association (1997) © Overseas Publishers Association N.V., with permission from Gordon and Breach Publishers.

© 2002 Taylor & Francis a measure of anxiety or fear. Both CBD and diazepam decreased the amount of time spent in the enclosed arms. Since these studies were conducted, Petitet et al. (1998) reported CBD is an antagonist of the CBX receptor in the micromolar range suggesting that CBD may have pharmacological effects as an antagonist of the CBj receptor.

Since the discovery of the synthetic, highly potent CBX receptor antagonist, SR 141716, by Rinaldi-Carmona, Barth, Heaulme et al., several other studies seem to support the hypothesis that CBX receptor antagonists have anxiolytic properties. Onaivi et al. (1998) used two tests of anxiety in mice, the elevated plus maze (as discussed above) and the two compartment black and white box test. When administered SR141716, in the elevated plus maze, mice spent more time in the open arms indicating a reduction of anxiety. In the second test, mice are allowed to choose to spend time in a two compartment box, one which is white and brightly lit, the other is black and dimly lit. Time spent in the dark compartment is taken as an index of anxiety. When administered SR141716A, mice spent more time in the white, brightly lit compartment indicating a reduction in anxiety. Taken together, these studies suggest that CBX receptor antagonists have anxiolytic properties.

How To Win Your War Against Anxiety Disorders

How To Win Your War Against Anxiety Disorders

Tips And Tricks For Relieving Anxiety... Fast Everyone feels anxious sometimes. Whether work is getting to us or we're simply having hard time managing all that we have to do, we can feel overwhelmed and worried that we might not be able to manage it all. When these feelings hit, we don't have to suffer. By taking some simple steps, you can begin to create a calmer attitude, one that not only helps you feel better, but one that allows you the chance to make better decisions about what you need to do next.

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