Itching for a Shot

Asthma medication may help treat itchy hives

(RxWiki News) People with allergies often have to take antihistamines to calm their allergy symptoms. For some people, antihistamines can cause unwanted side effects. Now these patients might have another treatment option.

A new study found that a monthly high-dose injection of the asthma drug omalizumab (sold as Xolair) might significantly reduce hives and severe itch for allergy patients.

Researchers treated 323 people with hives and severe rashes with three different doses of the asthma drug over a 12-week period.

The participants that received the highest doses of the medication experienced significant improvements in how many hives they developed and how severe their itch was.

"Consult your allergist if you get hives."

Marcus Maurer, MD, of the Charité-Universitätsmedizin in Berlin, Germany, and colleagues set out to study the safety and effectiveness of omalizumab in patients with chronic idiopathic urticaria, or very itchy hives.

Omalizumab was first approved in the United States in 2003 as a treatment for severe asthma.

To carry out their study, the researchers recruited 323 patients from sites in North America and Europe.

The participants were between the ages of 12 and 75 years. All had a history of very itchy hives for at least six months or eight consecutive weeks without improvement even when using the type of antihistamines that are usually prescribed to treat hives.

Participants were put into four treatment groups. Each group received three subcutaneous injections of 75, 150 or 300 milligrams of omalizumab or a fake drug (placebo).

The shots were given every four weeks for 12 weeks. Patients were then followed for 16 weeks.

During the treatment time, participants were allowed to continue taking their usual antihistamine medications. During the follow-up period, they were only allowed to take one additional antihistamine.

Rescue medication was provided when participants needed immediate relief from severely uncomfortable hives.

Study participants recorded their symptoms in a computer program. Each day, they reported how severe their itch was, the number of hives they had and the size of their largest hive.

The patients also reported how much their sleep and social lives were affected by the hives and if they had to use the rescue medication.

By week 12 of the study, the groups receiving the two highest doses of omalizumab had significant improvements in their symptoms.

The group receiving 150 mg of omalizumab reduced their average itch-severity scores by 8.1 points.

The group receiving 300 mg of omalizumab reduced their average itch-severity scores by 9.8 points.

The group receiving only 75 mg of the medication had the same score reduction as the fake medication group, meaning that they had no significant improvement.  

During the follow-up period, when the participants were no longer on the study medication, no groups reported significant reductions in their itch-severity.

The average weekly scores for hive numbers showed a similar pattern.

All three groups that received the omalizumab doses had a reduced average number of hives per week and less itching compared to the group that received the fake medication.

By week 12 of the study, 53 percent of participants in the 300 mg group were completely free of hives and 44 percent had no itching.

At the same point, 23 percent of the 150 mg group reported no hives and 22 percent reported no itching. 

Of the 75 mg group, 18 percent were hive-free and 16 percent had no itching.

In comparison, 10 percent of the fake medication group reported no hives and 5 percent had no itching.

Researchers also looked at how many of the participants needed to use the rescue medication during the study period.

The group receiving 300 mg of omalizumab took an average of 4.1 fewer rescue medication tablets at the end of the 12 weeks than they took at the beginning. The 150 mg group was taking an average of 3.7 fewer tablets.

The 75 mg group took an average of 2.3 fewer tablets than they had to take at the beginning of the study. The fake medication group took only 2.2 fewer tablets.

The researchers also looked at how safe the medication was for the patients. The proportion of patients with at least one adverse event during the study was similar for all three treatment groups. 

Adverse events included unexpected side effects, when a patient's asthma got worse or when a patient had to go to the hospital for emergency treatment, among others.

Of those receiving 300 mg of omalizumab, 65 percent had at least one adverse event. Of those in the 150 mg group, 67 percent had an adverse event. And 59 percent of the 75 mg group had at least one adverse event.

Similarly, 61 percent of those in the fake medication group had at least one adverse event.

During the entire 28 weeks of the study, there were nine reports of more serious adverse events.

Five were reported in the group receiving 300 mg of omalizumab, two in the placebo group and one each in the groups receiving 75 mg and 150 mg of omalizumab.

Most of the adverse events were reported in the 150 mg and 300 mg groups during the follow-up period, when no drug was being administered.

Over the course of the study, there were no deaths or episodes of anaphylactic shock – a strong allergic reaction that requires life-saving treatment.

“In conclusion, during the initial 12 weeks of our study, omalizumab at doses of 150 mg and 300 mg significantly improved outcomes as reported by patients with chronic idiopathic urticaria who remained symptomatic despite the use of approved doses of H1-antihistamines,” the authors wrote.

“The number of patients who were treated was too small to draw any definitive safety conclusions, but serious adverse events were more common in the group treated with the highest dose of omalizumab,” they wrote.

As a result, the researchers recommended further study to ensure the use of this drug for treatment of severe hives.

The study was published online on February 24 in the New England Journal of Medicine.

The research was funded by the companies Genentech and Novartis Pharma.

Many of the authors are employees of pharmaceutical companies, own stock in pharmaceutical companies and/or serve on their advisory boards. For more information please refer to the complete study.

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Review Date: 
March 5, 2013