Key takeaways:
- BiDil (isosorbide dinitrate/hydralazine) is the first FDA-approved medication for a single racial group — Black people with heart failure. But unlike isosorbide dinitrate and hydralazine, the two medications it’s made up of, there’s no generic version, so it can be expensive.
- When taken with other medications for heart failure, BiDil has been shown to help Black people stay out of the hospital and live longer with the condition.
- BiDil’s approval started a conversation about whether race should be considered when determining treatment.
In June 2005, the pharmaceutical company NitroMed made history when the FDA approved BiDil — the first medication marketed specifically for Black people. The approval came after initial studies showed no benefit, but a closer look found positive effects in Black Americans. Some saw this as a step toward personalized medicine, while others viewed it as a way for companies to market medications based on race.
Compared to other populations, Black people are disproportionately affected by heart failure, having higher prevalence and worse outcomes with the condition. And while finding a medication that can provide a significant benefit is important in lessening some of the health disparities between races, there are still a lot of unanswered questions as to why BiDil worked so much better in one population compared to others.
Here we’ll cover what you should know about BiDil and why it was specifically approved for use in Black people, even though providers may decide to prescribe it for people of any race.
What is BiDil?
BiDil is an oral medication that is a combination of two generic drugs — isosorbide dinitrate and hydralazine. They are both vasodilators, meaning that they work by relaxing your blood vessels.
Isosorbide dinitrate acts on both your arteries and veins by causing your body to release nitric oxide, which is key for relaxing your blood vessels. Hydralazine primarily works on your arteries but also helps keep nitric oxide around in your body longer.
BiDil is currently only available in one strength: a combination of isosorbide dinitrate 20 mg and hydralazine 37.5 mg. The two medications in BiDil have been used separately for many years to treat high blood pressure and chest pain. But they had never been in the same medication together for heart failure until BiDil was approved.
How does it treat heart failure?
When your heart is working normally, it pumps blood that is full of oxygen to your cells throughout your body. But when you have heart failure, it isn’t pumping as strongly as it should — causing you to feel tired or short of breath since your cells aren’t getting the oxygen they need.
When the medications in BiDil relax your blood vessels, your heart doesn’t have to work as hard, making it easier for blood and oxygen to get to your organs.
How do you take it?
The starting dose of BiDil is 1 tablet by mouth 3 times daily. Your provider will work with you to adjust your dose up to 2 tablets by mouth 3 times daily. For some people, this may happen more quickly — over the course of 3 to 5 days. But if you are experiencing side effects, you may need to have your dose adjusted more slowly.
It’s important to note that you won’t be taking BiDil alone for heart failure — your provider will have you take it in combination with a first-choice heart failure medication, like an ACE inhibitor, beta blocker, or diuretic (water pill).
What are the side effects?
When you start taking BiDil, you may get a headache or feel dizzy, especially as your provider adjusts your dose. This will generally lessen or go away after a few days. But if it doesn’t, your provider may lower your dose to help with the side effects.
The common side effects of BiDil include:
- Headache
- Dizziness
- Nausea
- Lightheadedness
- Feeling weak
Since BiDil causes your blood vessels to relax, this can sometimes cause your blood pressure to drop too low. Contact your provider immediately if your vision becomes blurry or if you feel like you are going to pass out. If you start experiencing chest pain, seek medical attention right away since this could be a sign of something more serious, like a heart attack.
Also, hydralazine, one of the ingredients in BiDil, can affect vitamin B6 (pyridoxine) levels in your body, causing numbness or tingling in your hands or feet. If this happens, your provider may recommend that you take a B6 supplement to help with this effect.
Why is BiDil specifically for Black people?
When BiDil was first studied, it didn’t show a significant benefit across the study population, which was over 70% white. In fact, the FDA didn’t approve the manufacturer’s new drug application (NDA) — the step needed for FDA approval — for this reason. But when researchers looked at how the medication worked in Black people specifically, it showed a positive effect on survival rate.
This resulted in another study called the African-American Heart Failure Trial (A-HeFT) that only included self-identified Black people with heart failure. The results showed that BiDil, when taken with other heart failure medications, could lower death by 43%. Hospitalizations for heart failure were also significantly less in the BiDil group. This was compared to a placebo group that did not receive the medication.
This is why the medication was ultimately FDA-approved — but only for self-identified Black people with heart failure. It’s also important to acknowledge that the study authors received support from NitroMed, the manufacturer of BiDil.
Is there any evidence that BiDil works better in Black people than in non-Black people?
As discussed above, the A-HeFT results showed a significant benefit for fixed doses of the medications as provided by BiDil in Black people when previous studies in a broader population did not. However, there were many critics of the FDA’s decision to approve a medication for a specific racial group — especially since there is no biological basis for race and there is incredible genetic diversity among people who identify as Black.
For example, some people may have more difficulty making and using nitric oxide, the key molecule involved in isosorbide dinitrate’s ability to relax blood vessels, as well as less active blood pressure regulation processes. And while this may not be universal across all Black people, studies suggest that it may be more common, on average, in people who self-identify as Black compared to people who identify as white.
In this case, people with less nitric oxide would possibly respond better to BiDil. However, some researchers think that the manufacturer used race as an easy way to identify those people.
That said, multiple factors can influence how someone responds to therapy — from genetics to environmental factors. But it’s important to keep in mind that genetics alone don’t tell the whole story. For example, we don’t see the same chronic disease trends in people of African descent in different areas of the world where racial discrimination is less prevalent.
Using race alone to make treatment decisions may cause some providers to overlook other reasons why someone may not be getting the most benefit from their medication. However, it is important to consider race as a factor in overall health as research has shown that racism and discrimination has an impact on how long and healthy our lives are.
But the FDA still says that the positive effects of BiDil in self-identified Black people are too great to be ignored, and that the medication does not appear to help other people in the same way. However, it is important to recognize that the same effects could be achieved by prescribing the two less expensive medications separately.
Has BiDil been shown to be more effective than similar medications in Black people?
During one study, BiDil was compared to enalapril — a first-choice medication for heart failure. Enalapril, an ACE inhibitor, also works by relaxing your blood vessels, but it does not affect nitric oxide like BiDil does.
Study participants were taking other heart failure medications and followed for 2 years. At the end of the study, more people in the BiDil group died than those in the enalapril group.
However, researchers later reviewed the data again and found that some Black people seemed to respond better to BiDil than enalapril. This ultimately led to the A-HeFT study that tested BiDil’s effects in Black participants, resulting in the medication’s approval.
How much does BiDil cost?
BiDil is only available as a brand-name medication, so there is no lower-cost generic version. This means it’ll be a little more expensive. But if you don’t have insurance, or if the medication isn’t covered, you can find ways to save on BiDil through GoodRx. The current price of BiDil is around $338 for 90 tablets with a free GoodRx discount. The same amount of the two medications, isosorbide dinitrate and hydralazine, prescribed separately would likely cost between $50 and $100 with GoodRx discounts.
The company that makes BiDil also offers a few ways to make your prescription more affordable. If you meet certain requirements, you may be eligible to use their copay assistance program. There are rules about who can use the program and dollar limits to the benefits, so make sure to read the fine print. But if you don’t qualify for the program, you can access lower prices by filling your prescription at specific pharmacies. Search for a participating pharmacy here.
What else should I know before taking BiDil?
BiDil doesn’t have many major drug interactions, but there’s one in particular that you need to know to avoid serious problems. One of BiDil’s ingredients, isosorbide dinitrate, is considered to be a “nitrate” medication. This type of medication should not be taken with commonly prescribed erectile dysfunction medications such as Viagra (sildenafil) or Cialis (tadalafil). Taking these medications together could cause your blood pressure to drop dangerously low — causing fainting, chest pain, or a heart attack.
It’s best to talk to your provider or pharmacist before starting any prescription or over-the-counter medications or supplements to make sure they’re safe to take with BiDil.
The bottom line
Studies show that the fixed doses of isosorbide dinitrate and hydralazine provided in BiDil are effective for Black people with heart failure, but the decision comes down to what is right for you as an individual. It’s an expensive medication, but the convenience of the combination offered by BiDil may be the right choice for a person who is not responding to first-choice medications alone.
Ultimately, the goal for people with heart failure is to stay out of the hospital and to keep your heart from getting any weaker. BiDil could be a lifesaving drug for you, but it’s important, as always, to discuss all of your options with your trusted healthcare team.
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