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From: dyer@spdcc.UUCP (Steve Dyer)
Newsgroups: sci.med
Subject: Re: Quinine and Mineral Water?
Message-ID: <445@spdcc.UUCP>
Date: Mon, 27-Oct-86 11:35:17 EST
Article-I.D.: spdcc.445
Posted: Mon Oct 27 11:35:17 1986
Date-Received: Mon, 27-Oct-86 22:30:21 EST
References: <4919@brl-smoke.ARPA>
Distribution: world
Organization: S.P. Dyer Computer Consulting, Cambridge MA
Lines: 42
Keywords: quinine, mineral water, myasthenia gravis

In article <4919@brl-smoke.ARPA>, abc@brl-smoke.ARPA (Brint Cooper ) writes:
> 	I have just learned, from a 1983 publication, that sufferers
> from myasthenia gravis (MG) should avoid the medical use of quinine and
> other anti-arrythmics (sp?).  The article didn't mention if the drinking
> of tonic water was also to be avoided.
> 	We spent July in Switzerland and Italy, where you buy your
> drinking water.  It is almost always a "mineral water," and the
> ingredients are tabulated on some labels.  This was my sole source of
> drinking water for a month and I drank several litres each day.
> 	Does anyone know what the chances are that quinine was present
> in any of the commercial mineral waters sold in Europe?  I am quite
> naive in this area; I haven't the foggiest notion of what quinine is.
> All I know is that, not long after returning from our trip, I suffered
> an attack of the MG that still hasn't relented in spite of taking lots
> more medicine and doing almost nothing physical.

Among its varied effects on all sorts of physiological systems, quinine
decreases the sensitivity of the neuromuscular junction to acetylcholine,
thus exacerbating a disease like myasthenia gravis which exerts its symptoms
through a reduction in the sensitivity of the neuromuscular junction to ACh.
A therapeutic dose of quinine, such as would be administered for leg cramps
or (rarely) for malaria, can produce an alarming intensification of symptoms
in MG patients, such as respiratory distress and difficulty in swallowing.
However, these are acute effects of the drug stemming directly from its
pharmacological actions on skeletal muscle; whether there are lasting sequelae
in an MG patient, I don't know.

Quinine is extremely bitter, and small quantities are used in "quinine water"
and "tonic water" as a bitter flavoring.  I'm not sure exactly how much drug
you'd receive from a typical gin and tonic, but I suspect it's very small.
If the mineral waters you drank in Europe didn't have the distinctive bitter
taste of tonic water (and most of the waters I've had in Europe don't), I
suspect that you don't have to worry about quinine being an ingredient.
What's more, all the reports I've seen mention quinine's ACUTE effects in
MG patients.  I think it's less likely that you could be exposed to quinine,
suffer no reaction, and then have a flareup due to the exposure weeks later.
Like a lot of other auto-immune diseases, MG symptoms maddeningly wax and
wane from stress, or for no apparent reason at all.  What does your doctor say?
-- 
Steve Dyer
dyer@harvard.HARVARD.EDU
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