Premarin: A Medication for Menopause
What is Premarin?
Premarin is a medication that contains a combination of estrogen hormones derived from the urine of pregnant mares. The name "Premarin" is derived from "PREgnant MAres' urINe." It is primarily used in hormone replacement therapy (HRT) for menopausal women to relieve symptoms associated with menopause. It’s also used in individuals who do not make enough estrogen for other reasons, such as having had one or both ovaries removed.
Premarin contains a mixture of different estrogens, including estrone, equilin, and equilenin, which are similar to the estrogens produced by a woman's ovaries before menopause. These estrogens help alleviate menopausal symptoms such as hot flashes, vaginal dryness, night sweats, and mood swings.
Premarin comes in two forms:
- Premarin oral tablet: systemic symptoms (moderate/severe hot flashes)
- Premarin vaginal/intravaginal cream: vaginal symptoms (moderate/severe vaginal dryness, pain during intercourse, and/or thinning/inflammation of the vagina)
It is important to note that Premarin must be used alongside some form of progesterone. When using Premarin, there is an increased risk of overgrowth of the uterine lining. Estrogen alone can stimulate the growth of the endometrium, which may lead to a condition called endometrial hyperplasia. Endometrial hyperplasia can increase the risk of endometrial cancer.
By combining progesterone with estrogen therapy, the progestin component counteracts the estrogen's effect on the uterine lining. Progesterone helps regulate the growth of the endometrium, preventing excessive thickening and reducing the risk of endometrial hyperplasia and cancer. This is why progesterone or progestin is typically prescribed along with Premarin or other estrogen therapies in women who have a uterus.
How Premarin Works
During menopause, a significant decrease in estrogen production occurs in the body. Estrogen plays a crucial role in maintaining the health of the uterus, ovaries, vagina, and various bodily functions such as bone and heart health. When estrogen levels decline, it leads to disruptions in these processes, resulting in symptoms like hot flashes and vaginal dryness.
Premarin is designed to replace the diminished estrogen in the body. It can be administered either locally as a cream specifically for the vagina or systemically as a tablet. While the cream is commonly prescribed to alleviate vaginal symptoms, it is important to note that it also gets absorbed into the body, potentially producing some systemic effects.
How to Take Premarin
Premarin is available in two formulations, and the recommended dosage and usage instructions may vary. It is generally advised to use the lowest effective dose for the shortest duration necessary.
For the cream formulation, the recommended starting dose is 0.5g, which can be inserted intravaginally or applied topically twice a week. If needed, a higher dosage may be prescribed in a cyclical manner, similar to a menstrual cycle. In this case, the cream is used for 21 consecutive days, followed by a 7-day break between cycles. During this regimen, the daily application may range from 0.5g to 2g, as directed by your healthcare provider.
The tablet formulation is slightly different. It can be taken continuously every day or in a cyclic manner, with 25 days of use followed by a 5-day break between cycles. It is important to note that women who have an intact uterus must also take progesterone for a minimum of 10 days per cycle to protect the lining of the uterus.
Who Can't Take These Medications
Yaz and Yasmin are generally safe for most individuals, but there are some considerations and contraindications to be aware of.
Do NOT use Yaz or Yasmin if you:
- Are pregnant
- Have breast cancer
- Experience undiagnosed vaginal bleeding
- Are within 6 weeks of delivery
- Smoke and are older than 35 years
- Have uncontrolled high blood pressure or diabetes
- Have heart diseaset
- Have a history of blood clot
- Experience migraines with aura
- Have active liver disease
The side effects of Premarin can vary slightly between the tablet and cream formulations. The tablet version may have similarities to birth control medications, while the cream formulation tends to produce more localized side effects.
Side effects that are typically experienced by more than 5% of individuals taking Premarin tablets include:
- Abdominal pain
- Mood changes
- Breast pain
- Overgrowth of the uterine lining*
- Increased vaginal discharge
- Irregular bleeding (spotting)**
*The use of progesterone often helps mitigate this side effect.
**If you experience any bleeding while using Premarin, it is important to consult your healthcare provider to rule out any underlying abnormalities and ensure that it is solely a side effect of the medication.
The vaginal cream formulation of Premarin has slightly different side effects. Since the cream is applied topically, the side effects are generally milder compared to the oral medication. However, they may be slightly more pronounced when the cream is used in a cyclical dosage regimen.
The most common side effects of the cream, experienced by more than 5% of individuals, include:
- Pelvic pain
- Breast pain
- Increased susceptibility to vaginal infections
It is important to note that you may not experience all or any of the mentioned side effects, but it is crucial to be aware of the potential risks associated with the medication. If you have any concerns or questions about the side effects, it is recommended to consult your healthcare provider for further guidance.
Who Should Not Take Premarin?
There are certain individuals who should avoid taking Premarin due to an increased risk of adverse effects related to the estrogen content in the medication. If you have been advised against taking estrogen-containing birth control in the past, it is likely that you will also be recommended to avoid Premarin and other menopause symptom-relief medications that contain estrogen.
The following individuals are typically advised to avoid using Premarin:
- Those experiencing vaginal bleeding of unknown cause
- Individuals with a history of breast cancer
- Individuals with a history of any estrogen- or progesterone-dependent cancer
- Those with a history of blood clots
- Individuals with severe liver disease
- Those who are known or suspected to be pregnant
If you still think Premarin might help you and your symptoms, it is important to speak with a healthcare provider about your health to see if the medication might be right for you.
- PREMARIN (conjugated estrogens) Vaginal Cream – Access data FDA-Approved Drugs [Internet]. [Revised 11/2017; accessed 5/2023].
- PREMARIN® (conjugated estrogens tablets, CSD) – Drug and Health Product Register Canada [Internet]. [Revised 06/2007; accessed 5/2023].
- Conjugated estrogens tablets consumer medicine information. Medsafe: New Zealand Medicines and Medical Devices Safety Authority. (n.d.). Retrieved May 18, 2023, from https://www.medsafe.govt.nz/consumers/cmi/p/premarin.pdf