Hi all. Just a quick question for you knowledgable folks. On many otc meds
there is a drug interaction warning about monoamine oxidase inhibitors. What
exactly is this. What types of medication has this. I have seen it on cough
syrup mostly, but am curious, please advise. Thankyou.
"If I didn’t have a head…………..I’d feel great"!
Parnate, Marplan and Nardil are the ones I remember but haven’t seen rxs for
them for years since the apparent success of the SSRIs. They are
antidepressants that lost favor probably also due to lots of drug and food
interactions.
Brad
"Mjup7" <mj…@aol.com> wrote in message
news:20010111162709.29049.00000997@ng-mj1.aol.com…
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> Hi all. Just a quick question for you knowledgable folks. On many otc meds
> there is a drug interaction warning about monoamine oxidase inhibitors.
What
> exactly is this. What types of medication has this. I have seen it on
cough
> syrup mostly, but am curious, please advise. Thankyou.
> "If I didn’t have a head…………..I’d feel great"!
A quick resume on MAO Inhibitors (i`ll be gladly corrected on any bits i
get wrong):
Mono-amine oxidase is an enzyme in the brain that breaks down mono-amines.
These mono-amines are some of the neurotransmitters such as noradrenaline,
serotonin and dopamine. Some of these, notably serotonin are beleived to be
reduced when people experience depression (although altered levels of these
transmitters are also implicated in an entire array of psychological and
psychiatric conditions – depending on which area of the brain is affected).
These drugs (MAO Inhibitors) reduce the amount of the enzyme (Mono-amine
oxidase) floating about, to bring about a rise in the levels of mono-amines
(setotonin, noradrenaline etc).
The catch is, these drugs also inhibit the break down of a substance called
Tyromine (spelling?) – this is a mono-amine that increases or decreases
blood pressure (well, it is one of the agents that does so). Tyromine
occurs naturally in the diet, notably, it occurs in quantity in things like
yeast extracts, blue cheese, some fish etc etc. Normally, the homeostatic
mechanism of the body deals with this intake, but if the mono-amine oxidase
is being inhibited by the drug, it won’t be able to do so, and so the blood
pressure could rocket, uncontrolled, skywards. This is bad.
Now, many drugs, notably the stimulants (which many meds contain, esp cough
meds) create a release of dopamine in the synapses of the brain cell (where
the action of the MAO Inhibitors take place). Things like amphetamine or
MDMA cause quite a rush of this drug to release, hence the experience of the
user.
Now, if the levels of these transmitters are already artificially high via
the MAO Inhibitors, i would imagine that taking a stimulant could be bad
too. (Maybe someone could correct me on this) .
The newer drugs such as the SSRI’s (prozac et al) appear to raise only the
levels of one type of neurotransmitter (serotonin) and so avoid the
Mono-amine oxidase/tyromine problem.#
Regards,
Andrew "read a book once" Austin.
On Fri, 12 Jan 2001 08:18:03 -0000, "Andrew T. Austin"
<slightlynerv…@NOSPAMbtinternet.com> wrote:
>A quick resume on MAO Inhibitors (i`ll be gladly corrected on any bits i
>get wrong):
>The catch is, these drugs also inhibit the break down of a substance called
>Tyromine (spelling?) – this is a mono-amine that increases or decreases
>blood pressure (well, it is one of the agents that does so). Tyromine
>occurs naturally in the diet, notably, it occurs in quantity in things like
>yeast extracts, blue cheese, some fish etc etc. Normally, the homeostatic
>mechanism of the body deals with this intake, but if the mono-amine oxidase
>is being inhibited by the drug, it won’t be able to do so, and so the blood
>pressure could rocket, uncontrolled, skywards. This is bad.
Actually, the problem is that normally there is lot of MAO in the gut
that metabolizes the tyramine, so an insignificant amount (some?
none?) is absorbed. So when someone on an MAOI eats something with a
lot of tyramine (old cheese, red wine), the tyramine gets into the
bloodstream, etc., etc. If the increase in BP is high enough, it can
cause blood vessels in the brain to burst -> stroke.
> Actually, the problem is that normally there is lot of MAO in the gut
> that metabolizes the tyramine, so an insignificant amount (some?
> none?) is absorbed. So when someone on an MAOI eats something with a
> lot of tyramine (old cheese, red wine), the tyramine gets into the
> bloodstream, etc., etc. If the increase in BP is high enough, it can
> cause blood vessels in the brain to burst -> stroke.
Ahhh…..i wasn`t aware of this bit. Many thanks for the correction.
Regards,
Andrew Austin.