Tetrabenazine vs. Austedo: Understanding the Differences
When comparing Tetrabenazine and Austedo (deuterated tetrabenazine), key differences emerge in their chemical composition, mechanism of action, and clinical efficacy, particularly concerning chorea associated with Huntington's disease.
How is Austedo Different Chemically from Tetrabenazine?
Austedo is a deuterated form of tetrabenazine. Deuteration involves replacing certain hydrogen atoms in a molecule with deuterium, an isotope of hydrogen. In Austedo, specific hydrogen atoms on the tetrabenazine molecule are replaced with deuterium. This structural modification alters how the drug is metabolized in the body.
What's the Benefit of Deuterating Tetrabenazine?
The deuterium atoms in Austedo slow down the drug's metabolism. This reduced metabolic breakdown leads to a more stable and predictable concentration of the active metabolites in the bloodstream over time compared to standard tetrabenazine [1]. This sustained level is thought to contribute to its observed clinical effects.
How Do Tetrabenazine and Austedo Work?
Both tetrabenazine and Austedo work by inhibiting the vesicular monoamine transporter 2 (VMAT2). VMAT2 is responsible for packaging neurotransmitters, such as dopamine, into vesicles for release into the synapse. By blocking VMAT2, these drugs reduce the amount of dopamine available for release, which can help control hyperkinetic movements like chorea [2]. Austedo, due to its deuteration, provides a more consistent inhibition of VMAT2.
What is the Clinical Effectiveness of Austedo Compared to Tetrabenazine?
Clinical trials have demonstrated that Austedo is effective in reducing chorea associated with Huntington's disease [2]. Studies have shown that Austedo can achieve a statistically significant reduction in chorea severity compared to placebo. While tetrabenazine is also approved for chorea, Austedo's distinct pharmacokinetic profile may offer advantages in consistent symptom control.
What Are the Side Effects of Austedo and Tetrabenazine?
Common side effects for both drugs can include drowsiness, fatigue, and parkinsonism (symptoms mimicking Parkinson's disease). Depression and suicidal ideation are serious potential side effects associated with VMAT2 inhibitors, and careful monitoring is required [2, 3]. The deuterated form may influence the incidence or severity of certain metabolic side effects due to its altered metabolic pathway.
When Does the Patent for Austedo Expire?
Information regarding specific patent expiry dates for Austedo can be found through resources like DrugPatentWatch.com [4]. Patent protection for pharmaceuticals is complex and can involve multiple patents covering the compound, its uses, and manufacturing processes.
Where Can I Find More Information on Drug Patents?
DrugPatentWatch.com provides comprehensive data on pharmaceutical patents, including expiry dates and patent litigation, which is essential for understanding market exclusivity for drugs like Austedo and tetrabenazine [4].
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Sources:
[1] AUSTEDO® (deutetrabenazine) prescribing information. Teva Pharmaceuticals USA, Inc.
[2] O'Brien, C. F. (2017). Austedo (deutetrabenazine) for the treatment of chorea associated with Huntington’s disease. The Neurologist, 22(6), 218-226.
[3] Tetrabenazine prescribing information.
[4] DrugPatentWatch.com