Citat:
Acute doses of cannabis and THC exert a definitive bronchodilator effect on the small airways of the lungs. The mechanism of this effect is not known, but it appears to be different from that of other drugs used at present as bronchodilators for asthma.
However, there have been very few studies on the bronchodilator effects of cannabinoids in asthmatic patients. All of these were studies carried out in the 1970s. Tashkin et al. studied 14 asthmatic volunteers and compared smoked cannabis (2%THC), oral THC (15mg) and the drug isoprenaline (0.5%). They found that smoked cannabis and oral THC produced significant bronchodilatation of at least two hours duration. The effect of smoked cannabis was nearly equivalent to the clinical dose of isoprenaline.
Smoked cannabis was also capable of reversing experimentally induced bronchospasm in three asthmatic subjects. Williams et al. compared a THC aerosol containing 0.2 mg THC with a salbutamol aerosol (0.1 mg) in 10 asthmatic subjects. Both drugs significantly improved respiratory function. The onset of effect was more rapid with salbutamol, but the effects of both drugs were equivalent at one hour. Tashkin et al. compared several doses of THC aerosol (5-20mg) with a standard dose of isoprenaline in 11 normal volunteers and five asthmatic subjects. In the normal subjects and three of the asthmatics, the bronchodilator effect of THC was less than that of isoprenaline after five minutes, but significantly greater after one to three hours.
(Please note: This text has been taken from a scientific article. Some sentences have been changed to improve understandability.) British Medical Association: Therapeutic Uses of Cannabis. Amsterdam: Harwood Academic Publishers, 1997
Det er nogen ret små studier der nævnes, og ved ikke om der senere er blevet forsket i det i større skala. Jeg tror tobakken er en værre faktor, så at vaporize eller ryge urten rent er nok det optimale.