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Re: [escepticos] marihuana
Hola Inés, cualquier fuente puede ser acusada de sesgo político/ideológico.
El problema del estudio controlado de la marihuana es que, como tal, es
imposible estandarizar un estudio terapéutico con la droga tal y como se
consume y, cuando se intenta, no hay modo de atribuir efectos positivos
y negativos a alguna en concreto de los cientos de substancias activas
(algunas sin caracterizar) que contiene un producto "crudo" de la maría.
Por ello, los pocos estudios "serios" (médicos) que hay no se realizan
con "maría", sino con preparaciones purificadas de algunos de los
alcaloides presentes en la hierba.
De todos modos, a ver si te sirve lo que dice la OMS en resuimen, que te
pego más abajo. COmo verás, sólo se refieren a los usos terapéuticos en
el párrafo final. Si te quedas con curiosidad, en el mismo sitio de la
OMS tienes un magnífico dossier para descargarte:
http://whqlibdoc.who.int/hq/1997/WHO_MSA_PSA_97.4.pdf
Eso sí, tendrás que practicas el inglés pues no tienen esas páginas en
español (o no las encuentro)
Salud,
oswaldo
Terminology
Cannabis is a generic term used to denote the several psychoactive
preparations of the plant Cannabis sativa. The major psychoactive
consituent in cannabis is ∆-9 tetrahydrocannabinol (THC). Compounds
which are structurally similar to THC are referred to as cannabinoids.
In addition, a number of recently identified compounds that differ
structurally from cannabinoids nevertheless share many of their
pharmacological properties. The Mexican term 'marijuana' is frequently
used in referring to cannabis leaves or other crude plant material in
many countries. The unpollinated female plants are called hashish.
Cannabis oil (hashish oil) is a concentrate of cannabinoids obtained by
solvent extraction of the crude plant material or of the resin.
Epidemiology
Cannabis is by far the most widely cultivated, trafficked and abused
illicit drug. Half of all drug seizures worldwide are cannabis seizures.
The geographical spread of those seizures is also global, covering
practically every country of the world. About 147 million people, 2.5%
of the world population, consume cannabis (annual prevalence) compared
with 0.2% consuming cocaine and 0.2% consuming opiates. In the present
decade, cannabis abuse has grown more rapidly than cocaine and opiate
abuse. The most rapid growth in cannabis abuse since the 1960s has been
in developed countries in North America, Western Europe and Australia.
Cannabis has become more closely linked to youth culture and the age of
initiation is usually lower than for other drugs. An analysis of
cannabis markets shows that low prices coincide with high levels of
abuse, and vice versa. Cannabis appears to be price-inelastic in the
short term, but fairly elastic over the longer term. Though the number
of cannabis consumers is greater than opiate and cocaine consumers, the
lower prices of cannabis mean that, in economic terms, the cannabis
market is much smaller than the opiate or cocaine market.
Acute health effects of cannabis use
The acute effects of cannabis use has been recognized for many years,
and recent studies have confirmed and extended earlier findings. These
may be summarized as follows:
* Cannabis impairs cognitive development (capabilities of
learning), including associative processes; free recall of previously
learned items is often impaired when cannabi is used both during
learning and recall periods;
* Cannabis impairs psychomotor performance in a wide variety of
tasks, such as motor coordination, divided attention, and operative
tasks of many types; human performance on complex machinery can be
impaired for as long as 24 hours after smoking as little as 20 mg of THC
in cannabis; there is an increased risk of motor vehicle accidents among
persons who drive when intoxicated by cannabis.
Chronic health effects of cannabis use
* selective impairment of cognitive functioning which include the
organization and integration of complex information involving various
mechanisms of attention and memory processes;
* prolonged use may lead to greater impairment, which may not
recover with cessation of use, and which could affect daily life functions;
* development of a cannabis dependence syndrome characterized by a
loss of control over cannabis use is likely in chronic users;
* cannabis use can exacerbate schizophrenia in affected individuals;
* epithetial injury of the trachea and major bronchi is caused by
long-term cannabis smoking;
* airway injury, lung inflammation, and impaired pulmonary defence
against infection from persistent cannabis consumption over prolonged
periods;
* heavy cannabis consumption is associated with a higher prevalence
of symptoms of chronic bronchitis and a higher incidence of acute
bronchitis than in the non-smoking cohort;
* cannabis used during pregnancy is associated with impairment in
fetal development leading to a reduction in birth weight;
* cannabis use during pregnancy may lead to postnatal risk of rare
forms of cancer although more research is needed in this area.
The health consequences of cannabis use in developing countries are
largely unknown beacuse of limited and non-systematic research, but
there is no reason a priori to expect that biological effects on
individuals in these populations would be substantially different to
what has been observed in developed countries. However, other
consequences might be different given the cultural and social
differences between countries.
Therapeutic uses of cannabinoids
Several studies have demonstrated the therapeutic effects of
cannabinoids for nausea and vomiting in the advanced stages of illnesses
such as cancer and AIDS. Dronabinol (tetrahydrocannabinol) has been
available by prescription for more than a decade in the USA. Other
therapeutic uses of cannabinoids are being demonstrated by controlled
studies, including treatment of asthma and glaucoma, as an
antidepressant, appetite stimulant, anticonvulsant and anti-spasmodic,
research in this area should continue. For example, more basic research
on the central and peripheral mechanisms of the effects of cannabinoids
on gastrointestinal function may improve the ability to alleviate nausea
and emesis. More research is needed on the basic neuropharmacology of
THC and other cannabinoids so that better therapeutic agents can be found.
Inés Toledo escribió:
Por favor, quisiera tener acceso a un estudio (a ser posible, en red),
con cierta profundidad, sobre los efectos de la marihuana.
Me gustaría que el estudio no tuviera relación con ninguna compañía
farmacéutica, y que tampoco tuviera que ver con ninguna campaña
política. Algo elaborado por especialistas médicos, químicos,
bioquímicos... con objeto de que no pueda ser refutado (al margen de sus
resultados, más o menos favorables o indulgentes hacia el consumo de
maría) con los argumentos de: "Seguro que quien lo hizo pretende
enriquecerse con alguna pastilla". No es que espere convencer a nadie,
es para mi propia información.
Si es una cuestión tratada en webs conocidas, de forma fiable, os
agradecería que me remitierais a ellas.
¿Sé me ha visto el plumero? ¿Os habéis dado cuenta de que estoy un poco
harta del
rollito-guay-naturista-drogas-ecológicas-mejores-que-cualquier-pastilla?
Gracias.
P.S: Ahora, cuando como sola o tengo un tiempo muerto, en lugar de
repanchingarme a ver teleseries, leo vuestros mensajes. Esta lista es
entretenida, y me está salvando de acabar enganchada a "Los Serrano",
que también son entretenidos, pero me enriquecen pelín menos. Un beso,
gracias de nuevo.
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