Topical Steroids Interaction With Birth Control Pills

Juli asked

Hello, I was wondering if putting .025% Triamcinolone Acetonide ointment or 2% Hydrocortisone cream for over 2 weeks on the cheeks of the face after a chemical burn would affect the efficacy of the Nexplanon implant (progestin-only birth control)? I read on PubMed that these topical steroid creams can have systemic effects if applied on broken skin, and Epocrates states that corticosteroids like dexamethasone and prednisone can induce hepatic metabolism of the etonogestrel contraceptive. Thank you in advance for your help!

Answer

You certainly are correct that there are potential interactions between corticosteroids (like prednisone and dexamethasone) and the hormones contained in birth control pills. However, the effect of topical steroids is less well known.

Interaction Between Corticosteroids And Birth Control Pills

There are a few interactions that can occur between the hormones in birth control pills (namely estrogen) and corticosteroids:

• Estrogens can increase the levels of circulating corticosteroids in the body, potentially increasing the risk of side effects such as infection, anxiety, and insomnia.
• Certain steroids, like dexamethasone, can induce (i.e. increase the activity) of the CYP3A4 metabolizing enzyme. This can potentially decrease estrogen levels, theoretically decreasing the effectiveness and increase the risk of side effects, such as breakthrough bleeding.

Estrogens increasing levels of corticosteroids in the body (the first bullet point) during co-administration has been well documented. There is no evidence, however, that corticosteroids will decrease the effectiveness of your birth control pills.

The concept of enzyme induction, when it comes to effects on birth control pills, has been studied extensively.

Certain drugs, like rifampin, are well known to cause decreases in hormone concentrations and precautions need to be taken if you a prescribed a drug known to be a strong enzyme inducer. Corticosteroids, however, are generally not thought to be strong enzyme inducers and have not been linked to decreases in birth control effectiveness.

Having said all of the above, as there is the potential for lower hormone concentrations due to the effects that some corticosteroids have on liver metabolism, there are a few sources (and 'drug-interaction checkers') that will recommend using back-up birth control in individuals on them.

There are many factors that can influence your risk for certain drug interactions and precautions that need to be taken. It would be prudent to discuss your unique medical situation with your doctor.

Are Topical Steroids Absorbed?

Topical steroids, such as the ones you mentioned in your question, can be absorbed systemically, and the extent of absorption is dependent on a few factors, including:

• Type of preparation (e.g. cream, ointment, emulsion, etc...)
• The integrity of the skin barrier (e.g is the skin broken?)
• Duration of therapy
• Presence of inflammation
• Application area

Topical preparations are in most cases, metabolized primarily in the skin, but a small amount may be absorbed systemically. Absorption may be increased in your situation, as the application site is on the face, on inflamed and broken skin. How this relates to potential drug interactions is unknown, unfortunately.

Final Words

There is clear evidence that there are interactions between the hormones in birth control pills and corticosteroids (such as dexamethasone).

However, results from studies indicate that the concern lies with increased levels of corticosteroids causing adverse reactions, not in a decrease in birth control effectiveness. There is no evidence that your birth control pills will be less effective.

When it comes to topical steroids, the extent of absorption depends on many factors and therefore, the risk of interactions will vary depending on the individual and situation.

Nevertheless, unplanned pregnancy has significant consequences and it never hurts to be too careful. Be sure to discuss your situation with your doctor for appropriate guidance as they have your complete medical history.