Uloric and Allopurinol for Gout: A Comparison

Published on August 9, 2019 by Sandy Liebhard

Uloric and allopurinol are indicated for the treatment of gout.

While they both reduce uric acid in the blood by inhibiting the action of xanthine oxidase, only Uloric is sold with a Black Box Warning regarding a risk of heart-related death.

Uloric and Allopurinol FDA Approval History

The U.S. Food & Drug Administration (FDA) approved allopurinol in 1966. The drug is sold under the brand name Zyloprim, and several manufacturers currently market generic versions

Takeda Pharmaceuticals received FDA approval for Uloric (febuxostat) in 2009. The agency approved the first generic version of febuxostat earlier this year.

Uloric and Allopurinol Similarities

Gout is a type of arthritis caused by excess levels of uric acid in the blood. Uloric and allopurinol treat gout by blocking xanthine oxidase, an enzyme that causes uric acid levels to increase.

These drugs are taken orally, in tablet form. They are available in two doses, and a lower dose of each is required to treat patients with kidney failure.

Uloric and allopurinol can cause gout to flare up immediately after the initiation of treatment, and both can cause some patients to experience serious and potentially life-threatening skin rashes.

However, febuxostat may be more effective at treating gout, as a recent study suggested 56.9% of Uloric users achieved satisfactory depression of uric acid levels versus only 44.8% of allopurinol users

Allopurinol Side Effects

Because allopurinol has been on the market for over 50 years, its side effects are well recognized. Patients should stop using allopurinol and contact their doctor right away if they experience:

• Life-threatening skin rash.
• Flu symptoms, joint pain, or unusual bruising or bleeding.
• Painful urination or blood in the urine.
• Little or no urination.
• Numbness, tingling, or burning pain.
• Worsening gout symptoms.
• Signs of liver problems, including loss of appetite, weight loss, stomach pain(upper right side), itching, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Uloric Side Effects

Patients taking Uloric should contact their doctor right away if they experience:

• Chest pain or heavy feeling in the chest.
• Pain spreading to the arm or shoulder.
• Nausea, sweating, or a general ill feeling.
• Dizziness or faintness.
• Sudden weakness or numbness, especially on one side of the body.
• Sudden headache.
• Confusion.
• Problems with balance, vision, or speech.
• Severe nausea or stomach pain.
• Fever.
• Loss of appetite.
• Dark-colored urine or clay-colored stools.
• Yellowing of the skin or eyes.

They should also contact their doctor if any of the following Uloric side effects fail to go away or become more severe:

• Nausea
• Mild dizziness
• Joint pain, stiffness, or swelling
• Mild skin rash

Uloric Black Box Warning

When the FDA approved Uloric in 2009, it did so on the condition that Takeda conduct a post-market study focusing on cardiovascular side effects. The trial, which was published in the New England Journal of Medicine in March 2018, ultimately concluded that the risk of all-cause mortality and cardiovascular death were higher with febuxostat compared to allopurinol.

Because of these findings, the FDA ordered Takeda to add a Black Box Warning – the strongest possible safety notice – to the Uloric label in February 2019. The agency also relegated Uloric to second-line status, limiting its use to gout patients who can’t tolerate or haven’t responded well to allopurinol.

A growing number of Uloric lawsuits filed since then accuse Takeda of concealing the heart side effects potentially associated with febuxostat.