Hi everyone. A few years ago I published a video about fertility
problems caused by having high levels of the hormone prolactin. Since then,
I have received many questions asking about the best medications used to treat high prolactin
levels. In today’s episode I will discuss the medications used to help your fertility.
Before we talk about the medications to treat high prolactin levels,
I want to briefly review who should be treated. The first step is to have a blood test to measure
your prolactin levels. Unfortunately, there are two systems of measurement which can be really
confusing. Here in the United States, we use Conventional Units. For the hormone prolactin,
you will most commonly see the measurement ng/ mL. In other areas of the world,
you may see measurement using SI units. This is also known as Le Système international
d'unités. An SI measurement for prolactin is given as micrograms per liter (μg/L) or milli
international units per liter (mIU/L). The actual number will not change. For example
25 ng/mL equals 25 mIU/L. However, if for some reason your lab gives you a measurement of nmol/L,
then you will need to convert it using this equation. There are also many websites that
can convert it for you. For the rest of this video, we will use conventional units
High prolactin levels are the ones that we are interested in treating. What is
a normal prolactin level? Normal levels can vary from one laboratory to another
because there are differences in how hormones like prolactin can be measured. For example,
a large laboratory in the USA called Labcorp has a normal range from 4.8 to 23.3. Quest
diagnostics has a normal range between 3 and 30. A level of 28 would be high at Labcorp
but normal at Quest. Be sure you and your doctor know the normal ranges of the lab you are using.
How and when you measure prolactin can influence your levels. Levels
should be measured in the morning after an overnight fast after an overnight fast soon
after your period has started but before ovulation. You should also make sure to
not stimulate your nipples. For example, don’t wear a tight bra before testing.
If your prolactin levels come back high, have a second test to look specifically
at your monomeric prolactin levels. There are several types of prolactin but only monomeric
prolactin levels are important. I talk more about that in my previous prolactin video.
Finally, before starting treatment, make sure you rule out other causes for high prolactin
levels such as medications you might be taking or problems with your thyroid.
OK. Finally, you have accurately tested your prolactin levels, have high levels and have
ruled out other causes. You are ready to start treatment. Based on where you live,
there may be different medications that are available to treat high prolactin
levels. Here in the United States, there are two medications which are
used most commonly. The first is called bromocriptine. It is sold under the brand
name Paroldel. These are some of the other brands of bromocriptine around the world.
Bromocriptine is an oral pill which is taken every day. Its most common side effects are nausea and
dizziness. To help alleviate those side effects, it is best to take bromocriptine at bedtime with
food. For some people, side effects can be reduced by placing the pill vaginally instead
of orally. Your doctor will likely start on the lowest dose possible, even half a tablet, and
then recheck your prolactin levels. If they come back still high, then the dose can be increased.
Cabergoline is another oral medication but is only taken once or twice a week. The brand sold in the
US is Dostinex. These are some of the other brands of cabergoline around the world. Cabergoline has
become more popular since the side effects of nausea and dizziness are less common and less
severe than with bromocriptine. People also like the fact that you don’t have to take it every day.
Which treatment is the best? There was one study which compiled a number of studies comparing
bromocriptine and cabergoline. They concluded that with a high degree of certainty that cabergoline
was better for people who stopped having their periods because of high prolactin levels. As
far as pregnancy rates, they also concluded that cabergoline was better but because the
quality of the studies they reviewed was not as good, that conclusion was less certain.
One thing to keep in mind is that cabergoline is a more expensive
medication than bromocriptine. For that reason, many physicians may opt to start
with bromocriptine and then switch to cabergoline if the patient was having
persistent side effects or if they were unable to lower the prolactin levels into the normal range.
For most people who start medication to control their prolactin levels,
they will see normal levels within about two to three weeks but some may take longer.
Our Infertility TV Bottom line is this. Both bromocriptine and cabergoline can be used to
treat high prolactin levels. If all you are trying to do is get your periods back, cabergoline may be
better for you. If you are trying to conceive, the choice is less certain. Bromocriptine is
less expensive than cabergoline but as to be taken more often and may have more side effects