Oral Zinc Supplementation to Enhance Botulinum Neurotoxin Response

Study Overview
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Brief Summary
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Botulinum neurotoxin (BoNT) is injected into muscles for treatment of dystonia. BoNTs are zinc proteases, and their enzymatic effect is reduced in the setting of low zinc. The study hypothesis is that a large enough fraction of unselected dystonia patients receiving BoNT injection have suboptimal zinc concentration in their tissues, and will experience improved response to BoNT if the injection is preceded by oral zinc supplementation (OZS). OZS consists of 50 mg of zinc acetate oral tablet each day for 7 days before injection. This is a double blind placebo controlled cross-over study, randomized order placebo and OZS, in patients at a neurology clinic on stable dose of BoNT.

Official Title
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Oral Zinc Supplementation to Enhance Effects of Botulinum Neurotoxin Injection: an n of 1 Study

Conditions
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Dystonia, Focal

Intervention / Treatment
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* Dietary Supplement: Zinc Acetate
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients of the PI Age 18-80 Male or female With an approved indication for BoNT such as dystonia or hemifacial spasm Have received either two or three BoNT injection cycles within the prior 8 months Prior two injection cycles length differed by no more than 2 weeks Prior two injection cycles used same brand of BoNT and similar dose within 15% Exclusion Criteria: Concommitant use of penicillamine or cisplatin

Ages Eligible for Study
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Minimum Age: 18 Months
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Single site randomized placebo controlled trial, cross-over
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: zinc, then placebo<br>Participants first received oral zinc acetate 50 mg tab each day for 7 days before scheduled BoNT injection. 3 months later participants received oral placebo (matching oral zinc) tablet each day for 7 days before scheduled BoNT injection. | Dietary Supplement: Zinc Acetate<br>* 50 mg tablet<br>Dietary Supplement: Placebo<br>* Zinc Acetate matched placebo tablet<br>|
| Experimental: placebo, then zinc<br>Participants first received placebo tablet (matching oral zinc) each day for 7 days before scheduled BoNT injection. 3 months later participants received oral zinc acetate 50 mg tablet each day for 7 days before scheduled BoNT injection. | Dietary Supplement: Zinc Acetate<br>* 50 mg tablet<br>Dietary Supplement: Placebo<br>* Zinc Acetate matched placebo tablet<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Patient Global Impression of Change | Patient selects one of three options: My response to BoNT injection with bottle A tablets was overall better than with bottle B tablets; My response to BoNT injection with bottle B tablets was overall better than bottle A tablets; or Neither BoNT injection with bottle A or with bottle B tablets was overall better than the other | End of study, week 48 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of participants with treatment-related adverse events | Unstructured interview soliciting side-effects in the interval since prior BoNT injection | At study visits 3 and 4, which are 3 months after the BoNT injection cycles with intervention OZS or placebo |