Reglan & Tardive Dyskinesia
Those who have suffered from a condition known as gastroparesis (a partial paralysis of the stomach), which prevents food from moving through the digestive tract, may have been treated with a drug called metoclopramide. This drug has been available in generic form since 1982 and is sold in the U.S. under the brand names Maxolon and Reglan (among others).
This drug has also been used to treat heartburn and acid reflux as well as nausea and vomiting (including those associated with cancer treatments). Some women have been prescribed the drug to stimulate lactation or to treat migraine headaches. Regardless of the reason why some people have been prescribed Reglan, those who are currently taking or have stopped taking the drug may be at risk of developing tardive dyskinesia (TD).
Brief History of Reglan
Metoclopramide was first developed in Europe in the mid-1960s as a dopamine antagonist. The medication can cause tardive dyskinesia and operates on the specific dopamine receptor identified as D2, which controls specific muscle functions as well as certain feedback mechanisms.
Prior to 2000, patients suffering from acid reflux disease and gastroparesis were treated with a drug known as Cisapride. Like several other drugs implicated in tardive dyskinesia and other movement disorders, Cisapride was the invention of the Belgian pharmaceutical company Janssen Pharmaceutica (a division of Johnson & Johnson), which marketed it in the U.S. under the trade name Propulsid.
Since 1982, the drug has been available in generic form. In January 2000, the FDA issued warnings that Cisapride was found to cause cardiac arrhythmia in certain patients and the drug was withdrawn from the U.S. market six months later. It is still used by veterinarians for the treatment of hairballs in house cats, however.
Among human patients, metoclopramide, an older medication that was considered "safer" than Cisapride, made a comeback after several years of taking a backseat to the latter.
Metoclopramide and Dyskinesia
In 2004, a research team that included medical scientists from the FDA and the Veteran's Administration published their study that came up with the following conclusion:
"Well-described TD risk factors were common in metoclopramide - associated TD reports. Given the Cisapride market withdrawal and associated increased metoclopramide utilization, the incidence of TD may increase accordingly. TD risk factors relative to the intended benefit and duration of use should be considered in metoclopramide prescribing."
The study found that older women who had been on the drug for an extended period of time had the greatest risk for developing symptoms of tardive dyskinesia. Additional risk factors included:
- "Organic" brain dysfunction/atrophy
- Substance abuse
- Genetic predisposition
It was not until 2009 that warnings were widely circulated.
Currently, 23 drug companies continue to manufacture and market metoclopramide and approximately two million Americans are still prescribed the drug for various digestive disorders. The FDA has since ordered manufacturers to include a "black box" warning with the medication's packaging when selling the product.
- Associated Press. "FDA Slaps Warning on Heartburn Drug Tied to Spasms" Baltimore Sun, 26 February 2009.
- Collins, Irene. "Metachlopromide Causes Tardive Dyskinesia." Science/Health News, 1 March 2009.
- Shaffer, Douglas et. al. "Tardive Dyskinesia and Metoclopramide Use: Effects of Cisapride Market Withdrawal." Journal of the American Pharmacists Association vol. 44 no. 6 (2004).