Pills, Patches and Creams

History:

Oral tablets or capsules are the most widely used forms of hormone replacement therapy (HRT). The biggest selling product is Premarin followed by Prempro (a combination of Premarin and medroxyprogesterone).  The first alternative to oral tablets was in the form of a transdermal (through the skin) estrogen patch that was used twice a week; but to prevent uterine cancer many women still had to take an oral progesterone compound along with the patch.  Currently patches are available containing both estrogen and a synthetic progesterone compound referred to as a progestin.  Some of these can be used just once a week.

There was a significant problem with the acceptance of the earlier patches.  Many women developed sensitivity to the adhesive and complained of pink marks that remained on the skin for days after the patch was removed.  Others found that the patches fell off prematurely. Fortunately, many of the newer patches don't have these problems.  Some of the patches are now the size of a quarter, and most use a new "matrix" design that eliminates much of the adhesive sensitivity problem.

Creams and Gels: Compounding pharmacies formulate various hormone creams and gels.  At first, these transdermal formulations were considered as alternatives for women who could not tolerate the adhesive on the patches.  More importantly, they later became useful because the primary care provider could easily alter the amount of the hormone to the patient’s individual needs.  These creams or gels do not seem to be patentable, so it is unlikely that any drug company will go to the expense of conducting studies on their effectiveness.  Also, because of the variable absorption depending on the base of the cream or gel, there is no standardization from pharmacy to pharmacy.

Most primary care providers like to refer to the same pharmacy or to use the same base for transdermal hormones.  Probably the most state-of-the-art base is that of a transorgano gel (also called PLO gel).

This water-based product has lipids added to it to increase skin penetration and to assist in drug delivery.  Studies have shown its effectiveness in the transdermal delivery of a variety of drugs.  This gel does not contain mineral oil that can reduce the absorption of some drugs.

Absorption:

The use of patches offers a convenience over taking a tablet every day. Creams/gels offer the primary care provider and the patient a way to adjust the dose to the patient’s individual needs. But there is another reason for choosing oral or transdermal therapy--how the drug is utilized by the body.

When a drug is taken orally, if it is absorbed in the digestive system, it then goes to the liver before it goes into the bloodstream.  The liver may act to change the drug into other compounds that may or may not act the same as the original drug. This is known as "first bypass" effect.  Using a transdermal form of hormone circumvents the first bypass effect, and in order to understand whether this circumvention is beneficial, it is necessary to look at the various hormones:

Estrogen

Estrogen goes through significant changes in the "first bypass" effect of the liver. For this reason, transdermal estrogen is better than oral estrogen for women who have:

 

Liver disease

Gallbladder disease

High blood pressure

History of blood clots

High triglycerides

 

Transdermal estrogen patches may be a better choice for women who suffer from frequent migraine headaches.  Some headache specialists feel that migraines may be induced by fluctuating hormone levels.  Because the patches deliver estrogen at a constant rate, fluctuating levels are avoided.

Progesterone

Oral micronized progesterone in oil, as the brand Prometrium or a compounded formulation, is the most absorbed type of progesterone. It is the only type of progesterone clinically proven to prevent the endometrial disease that may be caused by estrogen.

Transdermal progesterone may be useful for women to treat hot flashes.  The dose can be easily altered to treat the symptoms.  Due to their higher potency, the prescription strength progesterone gels are probably more effective for this purpose.  They are actually more economical than those purchased over-the-counter.

Testosterone

Testosterone has poor oral absorption.  It can be improved, much like progesterone, by using capsules of micronized testosterone in an oil suspension.  However, even this oral form is not as well absorbed as transdermal forms.  The synthetic methyltestosterone is well absorbed orally.  It would be a good choice for women who do not wish any estrogen effect because, unlike testosterone, it is not converted in the body to estrogen.

Transdermal testosterone is the most widely used form of testosterone.  It is well absorbed through the skin, particularly when a transorgano gel is used as a base.