Marijuana investigational

Carcinogenic activity. The dried leaf, administered intraperitoneally to rats of both sexes at a dose of 7 mg/kg/week, was active. The animals were irradiated with y radiation between 40 and 50 days of age and observed for 78 weeks. There was a greater incidence of tumors in animals given marijuana extract and y radiation than either marihuana or y radiation alone Cardiorespiratory effect. Fifty stable patients (25 males, 25 females) with methadone maintenance treatment (MMT) programs were investigated. Forty-six MMT... 

Information on the mutagenic potential of SNA Is almost completely lacking. A single abstract reported the cytogenetic effect of chronic use of the drug over 2-3 yr by one male and four females 18-26 yr old. The most frequent route of administration was Inhalation of smoke from a blend of SNA and marijuana. No chromosomal abnormalities were found In this limited investigation. 8... 

This book will focus on forensic pharmacology and drugs of abuse. Drugs of abuse, such as cocaine, heroin, marijuana, PCP, benzodiazepines, and methamphetamine, are often involved in criminal and civil matters concerning personal injury, motor vehicle accidents, drug overdose, and murder, and thus, are discussed to illustrate forensic pharmacology issues and investigations. 

The foliage of S. divinorum is prepared in various manners for use as a psychotropic agent. The dried leaves may be smoked like marijuana joints. Taking five or six rapid deep inhalations from one cigarette produces an effect similar to that of marijuana or taking the Salvia infusion. It has a duration of one to two hours (Ott 1993 Diaz 1975). The fresh leaves may be chewed and retained in the mouth. Blosser collected a strain of S. divinorum with leaves that are much less bitter than normal. His Mazatec informants made a "quid" of four to five pair of these fresh leaves and retained the juices in the mouth, which was more effective than ingesting them. This has been confirmed by other investigators, who have used the normal bitter strains. They state that the duration of such visions is from one to two hours (Siebert In press Blosser 1993 Ott 1993). 

A relatively large number of studies have investigated the effects of marijuana on focused attention, including reaction time tests and the DSST. Marijuana (1.8 and 3.6% THC) was shown to slow responding on a simple, visual reaction time task 242 however, others have not found marijuana to impair simple reaction time performance.11,40,236 Similarly, some studies have shown that marijuana impairs complex or choice reaction time tasks,11,233 whereas others have shown no effect.234 O Leary et al.243 found no effect of a 20-mg marijuana cigarette on reaction time in a dichotic listening task. 

Marijuana users will find that many employers weed out substance abusers, because they are much more likely to be absent or have on-the-job accidents. In 1996, about a third of all potential hires were screened for drug use. At major corporations, the figure was 81%, and in the top-ranked Fortune 200 companies, it rose to 98%. Standards at many federal agencies are even more stringent The Federal Bureau of Investigation (FBI) will disqualify applicants who had used marijuana within the past three years or a total of 15 times altogether. 

Chronic effects are frequent, habitual, and long-term. Investigators are also very interested in the chronic health effects of marijuana and THC and their influence on the lives of teenagers. The scientific literature discusses health effects of marijuana on bodily systems. 

Although significant advances have been made in recent years in the clinical evaluation of detrimental effects induced by developmental marijuana exposure, prospective longitudinal studies are currently underway. So far, they have preferentially investigated the cognitive effects of prenatal exposure to cannabis, with... 

Early in this century, much concern about use of marijuana was aroused in the Panama Canal area. The Army s investigative body came to the same conclusions as the 1894 Indian Hemp Commission that Cannabis is comparatively innocuous, that it s not addictive, etc. Another commission established soon after in New Orleans produced the same findings. The most famous of all these investigative bodies, the LaGuardia Commission, reported in 1943 on the use of marijuana in New York City with the same results. 

All claims about health drawbacks associated with the use of pot—aside from the effects of its being smoked—have been either refuted by other investigators or compromised when their results couldn t be replicated. Some of these reports have been received by their authors colleagues as irrelevant, highly suspect or worse. Since professional embarrassment has not deterred marijuana s critics, their alarming and widely-promulgated allegations should be confronted head-on. 

In December 1976, Psychology Today published "The War Over Marijuana, a review by Dr. Norman Zinberg of the preceding seven years of marijuana research. At a conference in San Francisco in late 1978, Zinberg, associated with the earliest "scientific investigation of marijuana and from the Harvard Medical School, described further developments regarding "Cannabis and Health" (a transcript of his remarks appears in the Journal of Psychedelic Drugs, January-June 1979) ... 

To sum up this discussion, it seems appropriate to quote again the panel from the National Academy of Sciences investigating marijuana users in the 1980s there is as yet "no conclusive evidence that marijuana causes permanent, long-term health damage in humans, is addictive, leads to use of harder drugs, affects the brain structure or causes birth defects. Fora fully detailed... 

Investigators in the Determinants of Myocardial Infarction Onset Study recently reported that smoking marijuana is a rare trigger of acute myocardial infarction (65). Interviews of 3882 patients (1258 women) were conducted on an average of 4 days after infarction. Reported use of marijuana in the hour preceding the first symptoms of myocardial infarction was compared with use in matched controls. Among the patients, 124 reported smoking marijuana in the previous year, 37 within 24 hours, and 9 within 1 hour of cardiac symptoms. The risk of myocardial infarction was increased 4.8 times over baseline in the 60 minutes after marijuana use and... 

The psychological effects of cannabis vary with personal and social factors. However, some guidance to the essential effects of the drug can be derived from investigations with THC and marijuana in non-user volunteers. Blood concentrations of THC over 75 pg/ml under these conditions are associated with euphoria, and somewhat higher concentrations with dissociation of events and memory and impairment of psychomotor tasks lasting over 24 hours (61). 

Suspected risk factors for obsessive-compulsive disorder were investigated in a prospective epidemiological study, using data from the Epidemiologic Catchment Area surveys (1980-1984) (176). Users of both cocaine and marijuana were at increased risk of obsessive-compulsive disorder compared with non-users of illicit drugs, but cocaine use alone was not associated with an increased risk, within the limited sample size. 

Chronic cocaine use, which is associated with immunosuppression, may be carcinogenic. The possible association between chronic cocaine exposure and pancreatic adenocarcinoma has been investigated (240,241). A study of hospital records in Brazil for the years 1986-1998 showed that of 198 patients with pancreatic adenocarcinoma, 13 (6.5%) were younger than 40 years of these, five had a history of chronic cocaine inhalation and one had abused marijuana. 

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