Many of us routinely use generic versions of brand name medications. These can include antibiotics, topical creams, antidepressants, birth control pills (BCPs), and many cardiovascular drugs. Generic drugs are supposed to be equivalent to the brand name version.
Yet I have had women swear that they had a different side effect profile or problems with breakthrough bleeding when they were switched to a generic version of a BCP. Here, in the WebMD Women’s Health Community we have had over a year of comments from women who were switched from the brand name birth control pill ®, to the generic version called ®. Some of the most frequent complaints have included: acne, headaches, worsened moods and increasing weight gain. A series of questions came into my mind about the use of generic birth control pills. The purpose of this blog is to share with you the answers I found.
What is a generic BCP?
According to the U.S. Food and Drug Administration (FDA), generics are “copies of brand name drugs that have exactly the same dose, intended use, side effects, route of administration, risks, safety, and strength as the original drug.” However, a generic version may have different colors, or inactive ingredients. The FDA estimates that 50% of generic drug production occurs in the same plants used to manufacture the brand name drugs (Office of Generic Drugs, FDA, 2009).
After a patent expires on a brand BCP, a drug company wanting to market a generic version must submit an abbreviated new drug application to the FDA. This process is streamlined so that the basic animal and then human studies do not need to be repeated since those studies were done when the brand name’s ingredients/doses were being approved (FDA, 2010). However, absorption of the generic compared to the brand name drug is studied. After reviewing 2,070 of these comparisons, it was found that the average difference in absorption was only 3.5%. When considering individual drugs, almost 98% of generics had absorptions (“area under the curve”) which were less than 10% off from the brand name (Davit, 2009). It is important to remember that there can also be similar variability between batches of the more expensive brand name drugs (FDA, 2009).
The American College of Obstetricians and Gynecologists published an opinion statement (number 375), “Brand versus generic oral contraceptives.” It supports patient or clinician preference in choice of BCPs as brand and generic are considered medically equal (ACOG, 2007).
Have there been known mistakes among generic BCPs?
Yes, according to Contraceptive Technology Update (April 1987), a packaging error placed white placebo pills in place of the active pills in generic versions of OrthoNovum 1/35® and Modicon®.. Fortunately, most of the defective packages were never shipped out from warehouses. Those few that were never reached consumers.
Forty-four companies that manufactured generic birth control pills and shots in lower income countries were assessed. Fourteen were studies in depth. The evaluation included a site visit to the factory to check on the facility, staff training, quality control and other manufacturing concerns. Of those 44 companies from 15 countries, less than 30% could meet the manufacturing standards developed by the World Health Organization (Hall, 2007).
Yet, it is worthwhile to note that even brand name medications, produced in first world countries, can have problems with production. In 1995 the original Today® birth control sponge was taken off the market due to manufacturing issues. In the fall of 2002 pre-filled syringes of Lunelle®, birth control shot, containing both synthetic estrogen and progesterone (like an injectable BCP), were recalled. The manufacturer found that some of the syringes lacked the potency reported on their labels. Thus generics produced in countries with strict manufacturing regulations may not have a higher risk for production problems than brand name products.
All of these examples pertain to problems on the part of the manufacturer. There may also be a margin of error among women using BCPs when the appearance (color of pills, packaging) of the product differs from the appearance of the medication the woman is accustomed to using. This might contribute to a new generic user’s mistakes in appropriate pill taking.
Why use a generic BCP?
While most would reply that reduced cost is the main reason to use a generic drug, one study found that compliance in taking medications was higher among those using a generic. Birth control pills were one of six types of medications analyzed among 7532 new prescriptions. After one year, those using generic drugs had a 12% higher rate of taking their medications regularly. Surprisingly, overall correct use of a daily BCP was only 54.8% over the year studied (Shrank, 2006). This would suggest that anything to increase compliance would be helpful.
What about differences in side effects between generic and brand name BCPs?
Generic drugs, by law, are required to look differently than their brand name counterparts — despite having the same medicinal effects. This has to do with trademark protection. Often a generic BCP will have different colors and/or different inactive ingredients (i.e., fillers) than the brand name version. One common filler is lactose/milk sugar. If one was lactose intolerant and changing BCPs from a non-lactose to lactose BCP filler perhaps there could be some gut upset. But honestly, I could not find a single published citation in the medical literature about a direct reaction to any filler product.
While the FDA requires all generics to have the same quality and performance as brand name products (FDA, 2009), there may be some individual differences between women in the way they metabolize a drug. It has been estimated that between 20-95% of differences in drug metabolism are influenced by genetics (Evans, 2003). For example the pathways in the liver which metabolize the estrogen in BCPs have been well documented to vary between persons. But one would assume that the ethinyl estradiol in both a brand name, and generic pill, would be handled similarly.
Let’s look at the concerns about purported differences in side effects between Yaz® and Gianvi®. Again the most frequent complaints have included: acne, headaches, worsened moods and increasing weight gain. The manufacturer of the generic Gianvi® is Teva Pharmaceuticals, a large, modern plant which produces many generics marketed in the USA. Thus it is unlikely that poor manufacturing standards are the culprit. Both Yaz® and Gianvi® contain the same hormones (esthinyl estradiol and drospirenone) in the same doses. However, in a lawsuit concluded in June 2010, Teva admitted to false advertising. Teva erroneously claimed that the ethinyl estradiol in Gianvi® had the same protection from oxidation as the brand name Yaz®. This patented use of another molecule to “protect” the estrogen was designed to extend the shelf life of Yaz®.
Many other BCP brands do not have this “protective” molecule with their estrogen. So it has apparently not been essential for pregnancy prevention. Would it be involved in a different set of side effects between Yaz® and Gianvi®? If a package of Gianvi® was quite old there MIGHT be a difference in estrogen effects. Yet it seems unlikely that the absence of this “protective” molecule would engender a totally new set of side effects.
It is important to remember that side effects can be a common issue for BCP users. In a group of 1657 women who were either new BCP starts, or switching birth control methods, 46% of those who discontinued BCPs cited side effects as the cause (Rosenberg, 1998). Thus, even without a change from a brand to generic version, BCP side effects may arise over time.
Is it true that low dose BCPs, as a generic, might increase my risk for pregnancy?
There are sources on the Internet which suggest that low dose BCPs containing 20 micrograms of ethinyl estradiol might not be as effective as their brand name counterparts. One writer argued that a 20 mcg pill could have reduced amounts of hormone absorbed since the FDA would allow a variation below the stated standard.
This argument contains two fallacies. As noted above, most every generic tested had absorptions which were within 10% of the brand name (i.e., that 20 mcg pill would become a 18 mcg pill). Second, pregnancy protection can exist at even the 10 microgram level, as evinced by the October, 2010 FDA approval of a 10 microgram BCP with 26 estrogen-containing pills (Lo Loestrin®). The successful use of the progestin only mini-pills is another example of how even BCPs without ANY estrogen can be effective contraception if more active pills are taken.
What should you do if it seems that a generic BCP is causing problems?
Ask to be switched back, or even switched to another generic version of the same formula. Many BCPs have more than one generic version. Remember that some generics are actually made by the brand name manufacturer. If the problems persist, be open to widening the search for the cause. Symptoms like breakthrough bleeding, mood swings, and weight gain can have other contributing factors.
Given that the average generic drug costs the consumer 80-85% less money (FDA, 2009) it may be worth our while to try a generic version. We have so many options from which to choose. I can count at least 70 BCPs available in the USA — and that does not include the progestin only minipills! After reviewing the published data on generic medications I feel very comfortable prescribing a generic BCP.