"Jean-Francois Coindet a doctor in Geneva, introduced iodine into the treatment of goitre in the year 1820. This was eight years after the discovery of iodine in the year 1813."
This short factual sentence epitomises an important advance in medicine.
It seemed to be of some interest to try to unravel how this
breakthrough was conceptualised, prepared and implemented, and to review
some of its early consequences. Iodine had only been discovered seven
or eight years earlier, its role in thyroid physiology was completely
unknown, and the cause of goitre was still conjectural, so it took
imagination, intellectual courage and determination to
complete such a study.
Coindet guessed that iodine was the substance in burned sponge that had been found to be effective in the treatment of goiter for at least seven centuries.
Coindet first communicated the results of his iodine treatment for
goitre to the Société Helvétique des Sciences Naturelles in Geneva on
July 21, 1820. His work became widely known from the three articles
(1820-1821) he published in his Bibliothèque Universelle (Geneva). The
first and the second articles also appeared in the Annales de Chimie et
de Physique (Paris), the journal in which the discovery and the
characteristics of iodine had previously been published, and they were
widely translated.
Coindet used three different preparations, a solution of potassium
iodide, an iodide-iodine solution somewhat different from the one that
Lugol later defined, and an alcoholic (tincture) solution that Coindet
later was to recommend as the safest and easiest to use. Twenty drops of
these solutions contained approximately 50 mg (one “French grain”) of
iodine. Coindet routinely prescribed 10 drops three times a day for the
first week, and then 15 drops thrice a day for the second week and 20
drops three times a day subsequently. He only rarely prescribed higher
doses. The recommended duration of treatment was 8-10 weeks. Results of
the treatment were spectacular: softening and shrinking of goitres
occurred after 8 days, and disappearance or a significant improvement in
disfiguring or uncomfortable goitres occurred later in many cases. In
addition, he observed iodine had a general stimulating effect on the
appetite, the uterus (?), acted as an aphrodisiac, and he concluded
that, used with competence, iodine would become one of the most potent
medication brought to medicine by modern chemistry !
Following Coindet's enthusiastic report on the efficacy of iodine, a
craze for taking iodine rapidly developed in Geneva and elsewhere. The
general public and more than a few physicians regarded it as a nostrum,
and rapidly, ill-effects from taking iodine were observed.
In February 1821, J-F Coindet published an article concerning
precautions and justification of iodine treatments. He reported
that he himself had treated 150 patients, in robust health, and had not
observed serious complications in any of them. Because of the public
uproar about the ill-effects seen with iodine, in January of 1821 he
requested the physicians, surgeons and pharmacists in Geneva to convene
at City Hall to officially confirm that in these patients no serious
ill-effects of iodine had been observed. Impressed by the aggressive effect of iodine on goitres, and
recognising its potential danger, Coindet insisted that the dose of
iodine be closely controlled, that patients be followed weekly and that
the treatment be short-term. He also would not give iodine to subjects
who were frail or nervous. Indeed, most of the complications which
raised the iodine controversy – and discredited its use – had not
occurred in Coindet’s patients, although his description of one of his
own patients resembled what we would now consider a typical case of
relapsing iodine-induced thyroiditis. Coindet noted that in several patients who had been given iodine by
others and who had developed iodine-induced hyperthyroidism — his
description being so classical that M. Greer suggested Jod-Basedow
should be renamed Jod-Coindet – the symptoms improved rapidly after he
treated them essentially by withdrawing iodine.
In contrast to the controversy that lingered in Geneva, Coindet received
wide recognition for his work abroad. A thoughtful review in the
Edinburgh Medical and Surgical Journal in 1824 stated : “…The physicians
and surgeons of France, of Italy, of Germany, and of England have,
since the publication of Dr. Coindet’s memoirs in 1820 and 1821, been
zealously occupied, in hospital or in private practice, in ascertaining
the powers of iodine, and observing its effects; and though, perhaps, in
some respects, it has been misapplied, and in others its virtues have
been overrated, it cannot be doubted that it possesses strong claims to
the attention of the bold and judicious practitioner”. In 1831,
J-F Coindet was awarded a major prize by the Paris Academy of Sciences.
Who truly discovered iodine?
Marine sponges and other marine species had been used since antiquity to
treat goitre. In 1815 – a time when Jean-Charles Coindet was an active
member – Andrew Fyfe reported to the Royal Society of Edinburgh that
sponge contained iodine. However, Fyfe did not publish his findings in
the Edinburgh Philosophical Journal until 1819. Coindet very
carefully pointed out that he had an intuition that iodine could be the
active anti-goitre substance contained in the ashes of marine sponge and
seaweeds 6 months before the publication of Fyfe’s findings. However,
it is not unlikely that his son Jean Charles had already told his father
about Fyfe's findings in 1815.
Iodine was discovered in Paris in 1811 by B. Courtois, the son of a
saltpeter manufacturer from Dijon. During the extraction of sodium and
potassium from the ashes of seaweed, in the presence of an excess of
concentrated sulphuric acid, he noticed the release of a violet vapour
which condensed on cold surfaces to form brilliant crystalline plates
(12). With the chemist C.B. Désormes, Courtois reported the discovery in
1813. In 1813, H. Davy, who had been admitted to France with a special
passport from Napoléon (despite the Continental Blockade) was given some
iodine crystal by Gay-Lussac. Davy, perhaps unsportingly, competed with
Gay-Lussac to be the first to report that iodine was a new element.
Later during the same visit to the Continent, Davy spent 3 months in
Geneva in 1814, where the discovery of iodine was widely discussed.
(The above history was in part extracted from the published details of History of modern thyroidology by the European thyroid association. Thanks to the authors of the article in making this information public and in detail.)
