Cannabis administration

In contrast, animal research is devoid of many of the above critiques and results are thus not confounded by, for example, polydrug use, low sample sizes, pretreatment differences, etc. Consequently, the main focus of this chapter rests on such animal models and the effects of acute and chronic cannabis administration on learning, memory, and related brain physiology. 

Methods for Clinical Research Involving Cannabis Administration... 

Monitoring of subjects during cannabis administration should include heart rate, blood pressure, and mental status. Subjects should not be discharged from research participation until reevaluation has shown that they have returned to baseline status. 

Subjects should not be discharged from a cannabis-administration research study until they have been evaluated for any unresolved or residual adverse effects from study participation. Adverse physical and psychological effects from acute cannabis administration, such as tachycardia, orthostatic hypotension, impaired motor coordination, and drowsiness, usually resolve completely within hours. Thus, subjects can usually be safely discharged a few hours to a... 

There are no known delayed adverse effects of cannabis administration. Assuming that the above precautions have been taken, there is little need for further follow-up of research subjects after their discharge from a cannabis-administration study. 

Periodic monitoring of heart rate and blood pressure during cannabis administration is recommended because of the expected effects of tachycardia and... 

Psychomotor performance refers to motor (movement) skills, eye-hand coordination, and speed of response to visual or auditory stimuH (often referred to as reaction time). Acute cannabis administration typically impairs psychomotor performance, with higher doses producing greater impairment (for reviews, see refs. 26-28). Numerous standardized tests measure various aspects of psychomotor performance (see Note 10). Impaired performance is observed within 30-45 min after smoking cannabis and persists for several hours. Some studies have documented performance decrements 12-24 h after smoking cannabis (29). 

Acute cardiovascular effects of cannabis administration include tachycardia, slightly increased blood pressure when supine, orthostatic hypotension, increased cardiac output, and decreased left ventricular ejection fraction (32,33). These effects increase myocardial oxygen demand at the same time... 

Acute cannabis administration is rarely associated with clinically significant ECG changes (32). Changes associated with tachycardia may be seen during monitoring, such as nonspecific, transient S-T segment or T-wave changes. 

Acute neurological effects of cannabis administration include headache, tremor, impaired balance, and impaired gross and fine motor coordination (37,38,40). The latter, especially in conjunction with drowsiness, increases the risk of motor vehicle accidents, falls, and other unintended injuries (41). Physical activity by subjects under the influence of caimabis should be limited and performed only in a protected environment that minimizes the risk of injury. Subjects should be advised not to drive, operate machinery, or engage in other potentially hazardous activities until it is clear that their coordination (and mental alertness) has returned to normal. 

Acute cannabis administration may cause pupil constriction, conjunctival injection ( red eye ), and dry mouth. These effects are mild and self-limiting... 

Acute psychomotor effects of cannabis administration include decreased postural balance (48,49), increased body sway (due to impaired equilibrium) (50), and increased tremor. Effects on simple and complex reaction time tasks are mixed, with some studies reporting impaired performance (51,52) and others showing no effect (50,53). Acute cannabis administration can also impair performance on the digit symbol substitution test (DSST) (9,13,49),... 

Cannabis administration acutely disrupts performance of complex tasks requiring continuous monitoring and the ability to shift attention rapidly between various stimuli (54,55). These same attentional abilities are required when operating a motor vehicle. Cannabis administration impairs performance on laboratory tests that model various components of driving (56) and increas-... 

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