|
Minoxidil (Rogaine)
An oral medication
called minoxidil (Loniten)
has been available
for a number of
years for the
treatment of high
blood pressure, but
because of its
serious side effects
on the heart and
general circulation,
it is only indicated
when the patient has
been unsuccessfully
treated with the
maximum doses of a
combination of a
water pill plus two
other hypertensive
drugs. In addition,
because of the
serious side
effects, such as
fluid retention and
heart failure,
minoxidil is only to
be used when the
high blood pressure
causes actual
symptoms or causes
damage to the
patient's internal
organs such as the
kidneys.
It was noted that
these patients who
were taking
minoxidil began
growing hair in
unusual areas of the
body, like the
forehead and the
backs of the hands.
It was thought that
applying minoxidil
directly to a bald
scalp might cause
hair growth in this
area as well. If
this hair growth
occurred without the
other side effects
of the medication,
it might be useful
in healthy balding
men. It was then
shown that when a
topical solution of
minoxidil was
applied to bald
scalps, some men did
indeed regrow some
hair in the area
where it was
applied.
Rogaine is the brand
name for the
topically applied
minoxidil solution
originally
trademarked by
Upjohn. It can now
be purchased
over-the-counter
without a
prescription in
either 2% or 5%
concentrations. It
appears that the 5%
is approximately 50%
more effective than
2% solution. The
greatest benefit
from the medication
is seen from 5
months to 2 years,
with gradual
decrease in
effectiveness after
that.
Although the
mechanism by which
minoxidil stimulates
hair growth is not
known, it probably
works by prolonging
the hair follicle
growth cycle
(increases the
length of anagen).
The effect of the
medication is to
increases the
quality of the hair
by increasing the
diameter and length
of miniaturized
(fine) hair. It does
not grow hair in
areas that are bald.
The controlled
studies on minoxidil
showed that it grows
hair in the vertex
(back part) of a
man's scalp, and it
probably works to a
small degree in
other parts of the
scalp as well,
although only in
areas that still
have some hair. In
addition, it was not
shown to regrow hair
in the front part of
a bald scalp (where
the effects of
balding are most
obvious).
It appears that
minoxidil's effects
may only be
temporary. Since
testosterone is
always present in
the blood stream,
the hormone
eventually overcomes
the effects of the
minoxidil so that
with time, men using
minoxidil continue
to bald, although at
a somewhat slower
rate. The
concomitant use of
minoxidil and
Propecia (see next
section) may
partially circumvent
this problem and
there is evidence
that in some cases
these drugs may act
synergistically.
Prior to trying
minoxidil, you
should know that
even if it is going
to work for you, it
may take 6-12 months
before you see any
results. In
addition, unless the
medication is used
consistently twice a
day, it will not be
of any benefit. For
most men, minoxidil
does not grow any
significant amount
of new hair. The
action of minoxidil
is to thicken
already existing
hair that is
miniaturized
(thinned from
genetic balding) and
most patients who do
grow hair, grow only
short, thin fuzz.
The majority of
patients who see an
effect from
minoxidil, see only
a delay or decrease
in the rate of hair
loss. This is the
most difficult
effect to measure
scientifically. For
many men, the
effects are first
noticed when they
stop using the
medication. Once the
drug is stopped, the
previous pattern of
hair loss resumes,
and any effects are
lost within two to
three months, even
if the medication
had been used for
many years. This
same limitation
applies to other
drugs used for hair
loss.
Many patients are
attracted to
minoxidil because of
its seeming lower
cost compared to
other methods of
hair replacement.
But, because the
effects of minoxidil
are temporary, the
lifetime cost of
using minoxidil can
be more expensive
than the cost of
hairpieces or
surgical treatments
for hair loss. Some
doctors recommend
minoxidil before and
after hair
transplantation to
decrease or prevent
the temporary loss
of hair that
sometimes occurs
with newly placed
grafts, but this
theory has not been
proven.
Minoxidil has been
prescribed in
conjunction with
other medications
such as topical
retinoic acid (Retin-A)
to increase its
topical penetration.
These medications
can greatly increase
the systemic
absorption of
minoxidil and may
increase the risk of
potential side
effects including
severe scalp
irritation. The
prescribing
information of
Upjohn specifically
states "Rogaine
should not be used
in conjunction with
other topical agents
including topical
corticosteroids,
retinoids, and
petrolatum or agents
that are known to
enhance cutaneous
drug absorption." In
addition, Retin-A
often causes
significant skin
irritation when used
alone and in
conjunction with
minoxidil. The
prescribing
instructions clearly
state "because
absorption of
minoxidil may be
increased and the
risk of side effects
may become
greater…you should
not use Rogaine if
your scalp becomes
irritated or is
sunburned."
A problem unique to
patients using the
combined mixture of
minoxidil/Retin-A
occurs when scalp
irritation begins
and the patient is
afraid to stop the
Retin-A since this
would also mean
discontinuation of
the minoxidil (and
the risk of
subsequent hair
loss). These
patients often
continue the mixture
in spite of the
development of
severe scalp
irritation. This can
result in infection,
scarring and
permanent hair loss.
Although it seems
that the topical
preparation of
minoxidil is
innocuous, the
long-term safety is
not known. As with
many medications,
the clinical trials
with minoxidil were
performed over a
very limited time
frame. Since the
medication must be
continued for years,
there may be
potential long-term
problems that we are
presently unaware
of.
Rogaine Use in Women
The early studies
with minoxidil were
on balding men, but
it appears that
minoxidil may
actually be more
effective in women.
This is probably
because women
usually exhibit a
more diffuse type of
hair loss so that
areas thin rather
than become totally
bald. Thus, there is
still hair present
for minoxidil to
"work on". As with
men, minoxidil is
only modestly
effective in
restoring one's hair
and it does not seem
to work in older,
post-menopausal
women.
Although the 5%
solution seems to be
more effective, it
is also stickier due
to it's higher
propylene glycol
content (the 2%
solution contains
more alcohol). This
makes it impractical
for many women to
use during the day.
As a compromise, it
is advised that
women use the 2%
alcohol based
solution in the AM
and the stronger 5%
propylene based
solution in the PM.
Side effects from
minoxidil are also
slightly different
in women than in
men. Women seem to
be a little more
sensitive to the
medication and have
an increased risk of
developing contact
dermatitis. A more
significant local
reaction is the
development of
facial hirsuitism.
The development of
facial hair slowly
resolves when the
medication is
discontinued but can
be a real nuisance
when it occurs.
Carefully trying to
avoid the medication
dripping down onto
the temples and
forehead seems to
reduce but not
totally prevent this
problem from
occurring.
Some women appear to
get light-headed or
hypotensive (develop
low blood pressure)
when using the
medication, but the
exact incidence and
significance of this
is unclear. |
