這篇文章 Iodine made easy 發表於 2011年五月.
Why is iodine safer today?
Iodophors were developed in the 1950s to overcome the side
effects associated with elemental iodine. These were found to be
safer and less painful, but just as effective as elemental iodine,
allowing widespread use.
Bonding iodine with another molecule makes it less toxic and
instead of high concentrations of iodine being released in a
single application, the iodine is slowly released from the reservoir
carrier molecule over a sustained period of time.
Iodophors are preparations that bind iodine to a solubilising
agent or carrier. The water-soluble complex allows the slow
release of a low concentration of free iodine when the carrier
comes into contact with wound exudate. This controlled release
of low concentrations of iodine helps to minimise the negative
side effects of using free elemental iodine.
When is iodine
indicated?
An international consensus document
on managing wound infection27,
recommends the use of antiseptic
dressings as being part of an overall
management plan in the following
circumstances:
n to prevent wound infection or
recurrence of infection in
patients at greatly increased risk of
infection
n to treat localised infection
n to treat spreading infection when
healing is delayed
Slow release iodine dressings have
been used to treat a range of wound
types where infection is present or
suspected.
These include pressure ulcers, venous leg
ulcers, diabetic foot ulcers, minor burns
and superficial skin-loss injuries24,28.
When are iodine dressings contraindicated?
Iodine dressings must be used under medical supervision in patients with
thyroid diseases, known or suspected iodine sensitivity, in pregnant or
breastfeeding women or in newborn babies and up to the age of six months8 .
Long-term use of PVP-I has been loosely associated with mild hyperthyroidism29
and long-term use is not recommended for patients with impaired thyroid
function. However, a number of studies have monitored thyroid function during
PVP-I clinical trials and have reported that it remains unchanged30–32. To
avoid toxicity or the hypothetical risk of thyroid-related complications,
iodine products should be used with caution in children, in those with large
burn areas, and where prolonged treatment of large open wounds is required. The
use of iodine dressings should also be avoided
before and after the use of radio-iodine
diagnostic tests (until permanent healing).
Reports of systemic effects following
short-term PVP-I treatment are extremely
rare. Iodine absorption has been found to
be dependent on the size of the wound
and the duration of treatment33. Hunt
et al31 also discovered a relationship
between wound area and iodine levels in
serum and urine following the treatment
of burn wounds with PVP-I, but it was
proposed that renal function was a
factor in the determination of this. Iodine
should, therefore be avoided in patients
with significant renal disease.
Summary
Although it has been speculated that iodine delays healing and is cytotoxic, there is
substantial evidence to suggest that the commonly-used low concentration, slow release
iodophors improve healing rates and are effective as highly potent antimicrobials with
a broad spectrum of activity, including antibiotic-resistant strains such as MRSA. It is
unfortunate that the concerns about iodine are based on studies that are so varied in
method and design that it is difficult to draw reliable comparisons and conclusions. The
reputation of iodine wound products, used as antimicrobials, suffered as a result of these
studies but it is now widely accepted that slow-releasing iodophor antimicrobials are safe
and have minimal detrimental impact on wound healing
