Biomedical Engineering Reference
In-Depth Information
Fig. 1
Structures of the main opiates
R
1
O
O
N
CH
3
H
O
R
2
R
1
R
2
-H
-H
Morphine
-CH
3
-H
Codeine
-H
-COCH
3
6-MAM
-COCH
3
-COCH
3
DAM
3.3
Heroin
Heroin is a diester of morphine (3,6-diacetil morphine or DAM) obtained from the
acetylation of both hydroxylic groups. It is a white, crystalline powder, with a bitter
taste. It is unstable in air and light and typically produces an odor of acetic acid.
Heroin, similarly to morphine, can be combined with acids producing water soluble
salts, such as heroin hydrochloride. Similarly to morphine, it possesses narcotic and
analgesic activity, but heroin causes strong addiction and intoxication. It is admin-
istered through inhalation, parenteral, subcutaneous, and above all intravenous.
3.3.1
Pharmacodynamics
The effects of heroin on the CNS are related to 6-monoacetylmorphine (6-MAM)
and mainly morphine. The heroin crosses the blood-brain barrier due to the acetylic
groups in position 3 and 6, that increase its lipophilicity. The morphinic compounds
interact with the opioid receptors, mainly the m receptors, acting as an antagonist by
mimicking the endorphin effects [
9
]. Usually the first event occurs 30 s after its
administration with a typical rush followed by a succession of euphoric sensations;
after a few minutes the user becomes calm, satisfied, and indifferent to his surround-
ings; after 2-4 h typical restlessness accompanied with pain and an incessant
demand for heroin sets in the craving.
The main symptoms of heroin use are miotic pupils, respiratory depression,
decreased blood pressure, reduced body temperature, and decreased reflexes, as
well as photophobia.
