From:
Sukie Crandall
Date: 2001-06-24 21:06:00 UTC
Subject: Re: melatonin
Well, I've followed melatonin work enough for a few years to have had
to do a bit of looking-up myself, due to knowing that some of the
claims made have been hypothetical, some disproven, and that there
have been some adverse effects seen. It has its uses and its
precautions like anything else.
Not having a lot of time right now I used one trusted and reputable
resource which compiles results well: the 2001 edition of the
_Physician's Directory for Nutritional Supplements_.
First the adverse effects: remember that some of these are very rare,
in fact one has been seen in only one individual, but others are not
at all unusual, so if using it recall that these MAY occur, just as
you would recall what adverse effects might happen with standard
meds, herbal meds, other supplements, etc. Drowsiness can occur;
typically this will happen about 30 minutes after ingestion and last
at least an hour when it occurs. One person had a psychotic episode
when it was combined with fluoxetine. Some of the side effects may
remind a person of fighting an early illness or having chronic
fatigue syndrome. For some there can be stomach discomfort. Things
like a feeling of "heavy head", grogginess, depression, lethargy, and
possibly headache may occur. Disorientation and amnesia have been
seen. In a study with children they found an increased tendency for
seizures to occur in those who had a history of seizures, so for that
reason and others it is not now recommended for children. Due to
problems like drowsiness and a hypothermic effect (body temperature
lowering) it is not recommended for the elderly or after certain
procedures. It can inhibit sexual responses and fertility with
ovarian functions especially affected if progestin is given at the
same time (which may have its uses, as well), in some retinal damage
has been encountered. Another less common response is gynocomastia
(breast enlargement in males). It is to be avoided by pregnant of
nursing women to be safest. Tiredness is the most common result
seen, which an be useful or dangerous depending on circumstances,
such as combating insomnia vs. operating a vehicle.
There are known herbal and drug interactions, and may be more that
are not, yet, known. Valerian, kava kava, and other herbs with
sedating effects should be avoided when melatonin is used. Similarly
drugs or supplements with sedating effects are to be avoided,
including alcohol, and 5-hydroxytryptophan. Avoid NSAIDS,
betablockers, fluoxetine, and some others. I read that it interacts
with fluoxamine but not have details. It can interfere with
corticosteroids and diminish their effects. It may augment isoniazid
and may augment interleukin 2 (which may be useful at times).
Melatonin supplements tend to have two origins: synthetic, or those
derived from cattle pineal glands. (As with other "glandulars" this
may be a concern for making sure that the sources are not imported.)
A quote with MY emphasis: "Supplemental melatonin MAY... have
antioxidant and anti-apoptotic activity." In relation to the
antioxidant effect it points out that "this activity is found only
with very high pharmaceutical doses of this substance" and goes on to
reflect upon the suspected nature of the activity: "ability to
inhibit metal ion-catalyzed oxidation processes", and later points
out that the mechanism of action is speculative.
A single nighttime dose is cleared by morning (after advancing the
naturally produced nighttiime by about 3 hours) peak but chronic
dosing results in some lipid (fat) storage of melatonin.
It has been effectively used in insomnia studies and has helped end
dependence on benzodiazepine.
For those who do not know the history of it being studied in relation
to hormonal cancers this began when it was noted that fully blind
people appear to have lower rates of some hormonal cancers (which in
later studies do not necessarily hold across cultures or locations --
part of that puzzle possibly being unraveled by the later finding
that skin light exposure may also reduce natural melatonin
production). That isn't mentioned here but it's part of what i
recall from earlier articles on the topic. The book goes on twice to
say that there may be some promise in that regard but that there is
no proof at this point: "Claims that melatonin can be used to
prevent or treat cancer or immune system dysfunction are unsupported
by current research. There is some very preliminary research data
suggesting some beneficial effects in animal models and in vitro
studies. A small amount of clinical work has been done, and more
seems to be warranted", AND "Use of the supplement in cancer and
immune disorders is unsupported by current research; there are some
promising findings but they are very preliminary".
It further says that there "is no evidence to substantiate claims
that melatonin can delay aging, be useful in cardiovascular disease,
depression, seasonal affective disorder, or sexual dysfunction" and
says that the anti-aging claim is "without foundation" and based upon
the incorrect concept that melatonin levels decrease with age when
studies have found them to be constant, and one "seriously flawed"
mouse study.
Like anything else it has it's uses, for instance the trial uses to
see if it may help ferrets with adrenal disease, but it also carries
precautions and it does have side-effects some of which like
lethargy, sore stomach, and depression may cause confusion for a
diagnosis if a vet does not know that supplement is being taken.
Remember that the pineal gland produces melatonin (as do extra pineal
glands in amphibians and other organ (at much lower levels) in
plants) and that darkness triggers and continues this production
while light ends it. There have been rodent studies (not mentioned
in this text, but recalled from earlier readings) showing that blue
of green light is especially detrimental in this regard and that even
low light levels reduce production. Anyone can therefore increase the
melatonin available to their ferrets by increasing the degree and
length of time of total or near-total darkness, without giving
supplements, by simply increasing the ferret's ability to make more
on its own with darkness.