Tobacco cannabis

Brody, S. and R. Preut. Cannabis, tobacco, and caffeine use modify the blood pressure reactivity protection of ascorbic acid. Pharmacol Biochem Behav 2002 72(4) 811-816. 

Vandrey, R. G., Budney, A. J., Hughes, J. R., and Liguori, A. (2008). A within-subject comparison of withdrawal symptoms during abstinence from cannabis, tobacco, and both substances. Drug Alcohol Depend. 92, 48-54. 

Although their results were encouraging, these studies demonstrated how difficult it is to treat cannabis dependence. Experience with treating tobacco dependence has revealed that a combination of various psychotherapeutic techniques and pharmacotherapies is more effective than either approach alone in producing and maintaining cessation. Thus, the use of medication during the cessation period may significantly improve quit rates and maintenance of abstinence. 

There is no conclusive evidence that moderate, long-term use of cannabis causes lasting damage to physical or mental health. However, it is probable that frequent inhalation of cannabis smoke over a period of years will contribute towards bronchitis and other respiratory disorders and possible cancers of the lung and parts of the digestive system. Risks are greater if cannabis is smoked with tobacco. 

Inhalation (IH) The administration of volatile gases and vapours, followed by drug absorption in the lungs or nasal mucosa. Examples include general anaesthetics like nitrous oxide, nicotine from the tar droplets in tobacco smoke, cannabinoids from cannabis leaf smoke and various opiates from burning opium resin. 

The pleasure derived from using tobacco is linked to the stimulation of dopamine-dependent neurotransmitter pathways in the brain, particularly in the meso-limbic system. The precise nature of this link remains controversial, but many of the neurophysiological processes underlying nicotine addiction are common to other addictive drugs with diverse pharmacological actions such as opiates, cannabis, alcohol and cocaine. 

One of the major toxicity issues in cannabis consumption relates to the fact that it is most often smoked. Cannabis and tobacco smoke, apart from having different psychoactive constituents, are actually very similar in their composition (Hoffman et ai. 1975). Cannabis smoke is mutagenic, which gives it carcinogenic potential (Nahas and Latour 1992). Although no specific reports of lung cancer or emphysema from cannabis smoke exist, it is at least as harmful as tobacco smoke, containing three times as much tar and five times as much carbon monoxide (Wu et al. 1988). Cannabis smoke inflames the airways and reduces respiratory capacity. Airway obstruction and squamous metaplasias may also occur. 

Comorbid dysthymia and substance disorder. A total of 642 patients were assessed. Thirty-nine had substance-related disorder and dysthymia (SRD-dysthymia) and 308 had SRD only. Data on past use were collected by a research associate using a questionnaire. The patients with SRD-dysthymia and SRD did not differ with regard to use of alcohol, tobacco, and benzodiazepines. The patients with SRD-dysthymia started caffeine use at an earlier age, had shorter use careers of cocaine, amphetamines, and opiates, and had fewer days of cocaine and cannabis use in the last year. They also had a lower rate of cannabis... 

Digital necrosis. An 18-year-old woman, with a history of severe anorexia nervosa of 5 years duration, who acknowledged regular use of tobacco and cannabis, was hospitalized for necrosis of the left index and thumb that had occurred shortly after left radial artery puncture for blood gas analysis. Acrocyanosis of the four limbs had been present since the onset of anorexia nervosa. Arteriography of the upper limbs showed major spasm of the left radial and cubital arteries and thromboses in the left interdigital arteries of the left index and thumb. The distal portions of the arteries were then on the left and on the right. The necrotic lesions healed after intravenous administration of ilomedine and interruption of tobacco and cannabis. Acrocyanosis of the four limbs persisted . 

---