Nereus: FDA Approves New Pill to Help With Motion Sickness

Nereus (tradipitant) is a new prescription medicine approved by the FDA to help prevent nausea and vomiting caused by motion (motion sickness) in adults, such as during car rides, boat trips, or flights.

Motion sickness happens when the brain receives conflicting signals from the eyes, the inner ear (which controls balance), and the body’s sense of position. This sensory mismatch can trigger the release of a chemical called substance P, which activates neurokinin-1 (NK-1) receptors in the brain. Together, these signals can cause nausea and vomiting, leading to motion sickness.

About 1 in 4 adults in the U.S. – roughly 65 million to 78 million people – are affected by a mild form of motion sickness while travelling by cars, boats, or planes. But about 5%-15% of people have severe motion sickness that can come back often, disrupting their day-to-day life. In some cases, intense motion sickness may cause people to avoid travel or motion-related activities altogether, resulting in missed opportunities and experiences.

Nereus is an oral NK-1 receptor antagonist that works by selectively blocking this nausea-triggering pathway at its source, without interfering or impairing other receptors in the brain. Thus, Nereus may offer a new way to help reduce vomiting.

This approval matters because Nereus is the first new prescription medicine for motion sickness approved by the FDA in more than 40 years. Nereus provides an additional option along with existing treatments for motion sickness, which include over-the-counter antihistamines and other prescription medicines.

Why Was It Approved?

The FDA’s approval of Nereus was based on three key clinical studies that showed that it could significantly reduce vomiting caused by motion sickness in adults (especially on boat trips) and was safe for short-term (acute) use.

The two phase III studies and one additional supporting study were carried out in real-world conditions on boats and involved adults with a history of motion sickness. In both the studies, the participants were randomly assigned in a 1:1:1 ratio to receive either an oral single dose of Nereus (85 mg or 170 mg) or a placebo, without food, about an hour before boat travel that lasted about two to five hours. The results showed that fewer people vomited when they took Nereus, compared to those on a placebo. In one trial involving 365 people, vomiting happened in 18.3%-19.5% of those taking Nereus versus 44.3% of those on a placebo. In another study of 316 people, vomiting rates were 10.4%-18.3% with Nereus versus 37.7% with a placebo. This represents a reduction in risk of about 50%-70%.

The most common side effects were drowsiness, a headache, and feeling tired. These were more likely to happen at the higher dose.

Nereus is meant to help prevent vomiting before it starts, and it was not tested for treating symptoms after they begin.

What Do I Need to Know?

Nereus comes as capsules containing 85 mg or 170 mg of the medicine. You take it as a single dose by mouth about an hour before you expect to be in motion, such as before your car ride or boat trip. You should take it on an empty stomach, either one hour before or two hours after you eat. You should not take more than one dose in a 24-hour period.

Nereus may cause drowsiness or tiredness, especially if it is taken with other medicines that affect the brain or if it is taken with alcohol. Until you know how Nereus affects you, avoid driving or using heavy equipment. Always inform your health care provider about all the medicines that you take, including over-the-counter products, herbal remedies, and vitamin supplements.

Nereus is not recommended in people with serious kidney or liver problems, as it hasn’t been studied in these conditions. Be sure to tell your health care provider if you are pregnant or planning to become pregnant, as it is not known if the medicine affects a fetus. If you are breastfeeding, talk to your health care provider, as Nereus may pass into your breast milk and make your baby sleepy.

At present, Nereus is not intended to treat nausea caused by other medical conditions, or vomiting caused as a side effect of certain medicines. Nereus is expected to be available soon.