Leland Guthrie
04/12/01
Psychopharmacology
Scopolamine
Scopolamine is in a family of anticholinergic hallucinogens along
with hyocyamine, and atropine. Although they can be synthesized in a
laboratory from various precursors, they are found naturally occurring
in four genuses of the Solanaceae (potato) family: Atropa, Datura,
Mandragora, and Hyoscyamus. People around the world have utilized the
effects of Scopolamine in manifold ways. Using extracts from Atropa
Belladonna which means beautiful woman, ancient Egyptian and Roman
women are supposed to have put the juice on their eyes leading to
larger pupils which was considered more beautiful. In more recent
times, the prolonged dilation of the pupils known as mydriosis, has
been effectively employed during opthamallogical procedures. Hamlet's
father in Shakespear's play was killed by "hebone" which is now
understood to have been Henbane, a Scopolamine containing plant in the
genus hyoscyamus. The witches of medieval times are thought to have
used ointments made of Atropa and rubbed on a broomstick to induce
feelings of flight and visions of travels to the Witches Sabbath.
Plants from the datura family were used by bands of thieves in India to
drug their victims into a stupor. It has also more recently come to
light that datura is a key ingredient in a paste used in Haiti to
maintain a lack of free will in people who had been resurrected from
their graves as Zombies to be enslaved for manual labor. The Oracle at
Delphi may have used datura to prophecy, while the the dung of beetles
fed datura was used to execute unfaithful lovers.
Scopolamine (C17H21NO4) is a heterocyclic compound with a single
chiral at its center bonded to a MeOH group. The Carbon makes up
67.31% of the composition while Hydrogen is 6.98%, Nitrogen 4.62% and
Oxygen 21.10%. Scopolamine is known by a few different scientific names
such as Benzenacetic acid, Hydroxymeythylscopolamine, scopine tropate,
tropic acid ester with scopine, L-scopolamine, and 6, 7-epoxytropene
tropate. Commercially it has been given names such as Buscopan,
Hyospasmol, Lotanal, Oportunin, Scop, Scopoderm, and Spasmofen.
Scopolamine has a molecular weight of 303.06 g/mol. It is very
unstable chemically, breaking down upon exposure to heat or light. For
this reason it is often kept in hydrated forms or as salts with HCL or
HBr. Products that contain Scopolamine such as the Transderm Scop,
often utilized the greater stability of the salt or hydrated forms in
their products. It is often taken for granted that Scopolamine and
Hyocine are the same substance. But, while the biological activity of
both is similar, Scopolamine is actually the enantiomer of hyocine.
Upon ingestion of Scopolamine through the Gastrointestinal tract,
or through mucous membranes, it travels through the blood and into the
parasympathetic nervous system. Here it blocks the transmission of
nerve impulses by acetylcholine and subsequently causes symptoms of
parasympathetic system depression. These symptoms include: dilated
pupils, rapid heartbeat, dry skin and mouth, and a blocking of the
mucous in the nose and throat. These anticholinergic affects also
inhibit the vestibular input to the CNS which directly inhibits the
vomiting reflex. This is the reason that Scopolamine can be found in
so many different motionsickness drugs. Because it depresses the
Central Nervous System, Scopolamine was used as a sedative anaesthetic
during surgery until the physicians were accused of sorcery due to the
bizarre nature of their patients dreams. For the same reason it is
also used as an antispasmodic to treat restlessness and agitation that
arises in disorders such as Parkinsonism, and delirium tremens.
Scopolamine also has an amnesiac effect, which is why it was used in
conjunction with the analgesic effects of morphine to ease the trauma
of birth. The combined effect, which was termed "Twilight Sleep," left
the mother semi-conscious during the birth, but eliminated all memory
of the painful process afterward. Towards the 1950's there was
growing concern about the fact that "Twilight Sleep" completely
separated the woman from the childbearing experience often remembering
nothing at all of the process afterwards. Another problem with the
procedure was that Scopolamine is readily transferred through the
placenta and into the blood of the fetus where it caused depressed
respiration and cardiac function. If not brought into the babies
bloodstream through the placenta, there was also a possibility of the
transfer of Scopolamine from the mother to newborn through breast milk.
The amnesiac effect has been more recently put to use in Colombia by
prostitutes and thieves. There, scopolamine has been isolated from a
Solanaceaeous tree known as Culera Borrachero (Methysticodendron
amesianum). Placed in food or drink, blown in the face, or placed in
chewing gum, it will render the victim disoriented and powerless to
resist orders. Often the victim will wake up days later, with no
recollection of what happened, only to find that their wallet and keys
are gone as well as all of money from their bank accounts. Because the
victims of Scopolamine overdose lose all memory of what happened, it is
difficult to assess the psychological effects of the drug although it
seems to lead one to become extremely passive and vulnerable to
suggestion.
The physical side effects of the drug can be more easily
measured. The wide range of unpleasurable side effects makes
Scopolamine and its plant sources low risk abuse substances. The most
common side effects, due in part to the depression of the Central
Nervous System, include but are not limited to hypotention, a widening
of the QRS complex, arrhythmias, muscle paralysis, delirium, delusions,
stupor, restlessness, giddyness, disorientation, persistent memory
disturbances leading to complete amnesia, hallucinations, constipation,
and confusion. In studies done on the effects of Datura, the
peripheral anticholinergic effects include sinus tachycardia,
hyperpyrexia, mydriasis, tachypnea, urinary retention, thirst, and dry
mucous membranes. Hyperpyrexia is much less commmon, occurring in 18%
of cases in one study. Seizures are rare, occurring in only one of 73
case series. The single most common central antichonlinergic effect is
hallucinations, coupled with bizzare and combative behavior. Patients
are observed flailing and picking at clothing or imaginary objects. The
discontinutation of use after a long period of time will induce certain
withdrawal symptoms including dizziness, nausea, vomiting, headache and
disturbances of equilibrium.
Glen Calvin
Psychopharmacology
Professor Morgan
4/12/2001
Scopolamine, a naturally occurring tertiary amine antimuscarinic,
constitutes the primary antimuscarinic component of the belladonna
alkaloids (AHFS 2001). Although it may be synthetically produced,
scopolamine is more typically extracted from the various members of the
Solanacea genus of the plants including Datura matel (datura herb), D.
stramonium (Jimson weed), Duboisia myoporoides, Hyoscyamus niger
(henbane), and Scopolia carniolica (AHFS 2001). Scopolamine is
considered to be the single most effective drug for the prevention of
nausea and/or vomiting induced by motion and also may be used during
recovery from anesthesia and surgery, but its usefulness in long term
therapy is limited by its adverse effects, particularly upon the
central nervous system (CNS) (AHFS 2001). AHFS also notes that
"Scopolamine has been used in the symptomatic treatment of parkinsonian
syndrome, including postencephalitic parkinsonian syndrome, and other
spastic states and as an anticholinergic CNS depressant (AHFS 2001)."
Scopolamine blocks acetycholine (ACh) synapses (Kalat 1995).
Acetycholine falls under the Biogenic amines (contains NH2 group)
category of neurotransmitters and is primarily associated with skeletal
muscles (Kalat 1995). People under the influence of scopolamine
exhibit obvious deficiencies on a variety of memory tasks and reflect a
general pattern of performance similar to that of senile people (they
showed the greatest impairment on the same memory tasks which posed the
greatest trouble for senile people (Kalat 1995). Scopolamine is one of
three anticholinergic hallucinogens (hyoscyamine and atropine are the
other two) whose effects are the result of blocking the muscarinic
cholinergic receptors in the brain (Palfai and Jankiewicz 1997).
Scopolamine hallucinations are a result of the antagonism of ACh
receptors (Palfai and Jankiewicz 1997). Scopolamine research has
played a recent and active role in attempts to understand and alleviate
the symptoms of Alzheimer's disease (AD). The role of the cholinergic
system in memory was discovered through studies in which scopolamine (a
cholinergic agonist) produced amnesia in health individuals, although
the exact specifications of the mechanism are not yet known. (Martin
1998). "Scopolaime was normally administered with analgesia during
surgery; women in labor would report not being able to recall events
during the delivery when they were given scopolamine (Martin 1998).
Experiments found that scopolamine impairs non verbal IQ in healthy
individuals, but not verbal IQ (Martin 1998). "Scopolamine testing may
serve as an index of the status of central cholinergic functional
integrity, and may ultimately prove useful as a diagnostic or staging
test in the evaluation of the cholinergic system in dementia
(Sunderland 1985). Understanding of the effects of scopolamine on both
neurochemistry and cognitive functioning led to the development of
pharmacological treatments which attempt to prolong the action of
acetycholine and perhaps enhance memory and/or cognitive performance
(Martin 1998). Limited success was met. Because scopolamine can cause
deficits in short-term memory in humans and deficits in animal memory
tests, it is believed that the cholinergic pathways and their
connections may allow the formation and consolidation of new memories
(Martin 1999).
Scopolamine is capable of blocking acetycholine at the receptor
sites of the actual target organs (smooth muscles and glands) of the
parasympathetic nervous system (Hamilton and Timmons 1990). More
simply put, the "command system" of the autonomic nervous system
continues to function while the final response is blocked (Hamilton and
Timmons 1990). Scopolamine has both central and peripheral blocking
affects which poses a problem for its usage. Adding a fourth radical
biochemically changes scopolamine to a new compound called methyl
scopolamine which is unable to cross the blood-brain barrier (Hamilton
and Timmons 1990). This is an extremely useful property because the
effects of scopolamine can then be isolated to the peripheral
parasympathetic systems, leaving brain acetycholine systems unaffected
(Hamilton and Timmons 1990). Experimental studies have shown that
"standard scopolamine reduces the response to punishment, nonreward,
and conflict, whereas methyl scopolamine (which has the same or even
more potent peripheral effects) has no effect on these behaviors
(Hamilton and Timmons 1990).
Scopolamine is an anticholinergic drug believed to have a
neurochemical profile different from the benzodiazepines. A
recent double-blind study designed to examine the memory-impairing
effects of scopolamine showed that it "produced dose-related reductions
in both true and false recognition rates, and induced a more
conservative response bias relative to placebo for recollection-based
'remember' responses to studied words" (Mintzer, Griffiths 2001).
Another double-blind study designed to test attention, recognition
memory, lexical decision, auditory oddball reaction time, and event
related potentials (ERPs) found a significant reduction in verbal
recognition memory performance specifically relating to the encoding of
verbal material (Potter, Pickles, Roberts, Rugg 2000). Additionally,
auditory P3 waves recorded from frontal central and parietal areas
showed only limited evidence of either latency increase or amplitude
reduction and two potentially confounding drug-related ERP modulations
were observed prior to or during the latency of the P3, the first being
a widespread increase of N2 amplitude and latency preceding the P3, and
the second was that the ERPs became relatively more negative at frontal
and central sites in the 200-450 msec latency range in both target and
non-target conditions (Potter, Pickles, Roberts, Rugg 2000). Other
double blind studies have yielded various scopolamine related findings.
One electro encephalagram (EEG) study showed that scopolamine increased
relative power in both the theta and beta frequency bands (Knott, Harr,
Ilivitsky 1997). Another scopolamine study partially supports the idea
of an interactive role of cholinergic and serotonergic systems in
cerebral mechanisms (Meador, Loring, Hendrix, Nichols, 1995). In
monkeys, scopolamine has also been found to cause behavioral deficit in
recency memory tasks while leaving neurons in the anterior-ventral
inferior temporal (IFT) cortex (a region having an important role in
visual memory and neuronal properties consistent with that role)
relatively unaffected (Miller, Desimone 1993).
References
AHFS Drug Information 2001
Hamilton, Leonard W. and Timmons, Robin C. Principles of Behavioral
Pharmacology, Prentice Hall, Engelwood Cliffs, 1990.
Kalat, Jame W. Biological Psycholoy, Brook/Cole Publishing Company,
1995.
Knott, Harr, Ilivitsky, 1997. EEG correlates of acute nicotenic and
muscarinic cholinergic blockade, Separate and combined administration
of mecamylamine and scopolamine in normal human subjects. Human
Psychopharmacology Clinical and Experimental, Nov Dec, Vol. 12(6) 573
582. Abstract
Martin, Neil G. Human Neuropsychology Prentice Hall, London. 1999.
Meador, Loring, Hendrix, Nichols, 1995. Synergistic anticholinergic
and antiserotonergic effects in humans. Journal of Clinical and
Experimental Neuropsychology, Aug. Vol 17(4) 611 621. Abstract
Miller, Desimone, 1993. Scopolamine affects short-term memory but not
inferior temporal neurons. Neuroreport an International journal for
the Rapid Comunication of Research in Neuroscience, Jan. Vol 4(1) 81
84. Abstract
Mintzer, Griffiths, 2001. Acute dose effects of scopolamine on false
recognition. Psychopharmacology, Feb. Vol 153(4) 425 433. Abstract
Palfai,T.and Jankiewicz,H. Drugs and Human Behavior, McGraw Hill Co.,
1997.
Potter, Pickles, Roberts, Rugg, 2000. The effect of cholinergic
receptor blockade by scopolamine on memory and performance and the
auditory P3. Journal of Psychophysiology, Vol 14(1) 11 23. Abstract
Sunderland, et al, 1985. Scopolamine challenges in Alzheimers disease.
Psychopharmacology, Oct. Vol 87(2) 247 249. Abstract
Works Cited
Ardila A; Moreno C
Scopolamine intoxication as a model of transient global amnesia. Brain
Cogn. 1991 Mar; 15(2): 236-45
Binotto, J.; Chahal, S.; Khan, S.; Li, B.; Rispler, A.(n.d.). A
General Review of the Chemistry and Utility of Scopolamine.
(2001, April 01).
Bradley, & Fink(1968). Progress in Brain Research: Vol. 28.
Anticholinergic Drugs and Brain Functions in Animals and Man.
Amsterdam: Elsevier Publishing Company.
Donovan, J.W. (2000). Datura Species—Natural Hallucinogens. Journal of
Toxicology: Clinical Toxicology, March v38(i2), 204.
Palfai, T & Jankiewicz, H. (1997). Drugs and Human Behavior (2nd ed.).
New York: McGraw Hill Companies
Richter, Conrad. Drug Derived from Herb Used to Rob or Rape Victims.
(2000, September 7).
Sopchak, C.A.; Stork, C.M.; Cantor, R.M.; Ohara, P.E. (1998). Central
anticholinergic syndrome due to Jimson weed physostigmine: therapy
revisited? Journal of Toxicology: Clinical Toxicology, Jan-March
(v36), 43.
Unknown (2001). Scopolamine. In The Columbia Encyclopedia, Sixth
Edition. Columbia University Press.
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