Transfer of Mexiletine into Breast Milk: A Case Report.

Background: Mexiletine is a class 1B antiarrhythmic agent, used to treat ventricular arrhythmias, and noncardiac-related problems such as myotonia. Limited safety data are available on the transfer of this drug into breast milk. Case Report: We report the case of a woman diagnosed with myotonia congenita who breastfed two children after two consecutive pregnancies. During the breastfeeding of the first and the second infant, she collected, respectively, five and seven samples at 0, 2, 4, 6, and 8 hours and 0, 1, 2, 3, 4, 6, and 8 hours after taking 200 mg of mexiletine thrice daily for seven doses. One week after the collection, samples were analyzed with a validated liquid chromatography tandem mass spectrometry method. No side effect was observed in either child according to the mother. Results: Using the mean milk concentrations, it is estimated that an exclusively breastfed infant would receive a maximum of 5.14% of the initial pediatric mexiletine dosage. We calculated a maximum of 2.67% for the first infant in our case, considering a nonexclusive breastfeeding. Maximal concentrations were observed 1-2 hours after the dose of mexiletine. Results seem to be in accordance with the two cases previously published. Conclusions: Mexiletine transfers into breast milk in low levels. However, results are obtained from only one woman. Therefore, caution should be used when mexiletine is prescribed to breastfeeding women. More cases are needed to evaluate the interindividual variability and to guide women regarding breastfeeding with mexiletine.

Shear wave elastography potential to characterize spastic muscles in stroke survivors: Literature review.

BACKGROUND: Post-stroke spasticity contributes to impairments, disabilities and decline in quality of life. Quantitative measurements of spasticity are needed in order to assess the impact of specific treatments and to choose the more accurate technique for each patient. The aim of this review is to examine the use of shear wave ultrasound elastography as a quantitative tool for monitoring biomechanical muscle properties such as stiffness and to determine whether it is a reliable method to assess spastic muscle in stroke survivors. METHODS: Studies were sought from Academic Search Complete, CINAHL, PubMed/Medline, Scopus and SportDiscus with the following keywords: shear wave elastography, spasticity, stiffness, elasticity, hardness, stroke, cerebrovascular accident, cerebral vascular event and transient ischaemic attack. Titles and abstracts were screened, and relevant full-text articles were retrieved for further review. FINDINGS: Of the 76 screened studies, nine captured elastography data of the spastic biceps brachii (n = 6) or the plantar flexors (n = 3) with stroke victims. All consulted studies had a different way of utilizing this technology which was expected considering no guidelines had been developed. Shear wave speed values obtained are compared and discussed with clinical measures. Reliability of the devices is also discussed. INTERPRETATION: Shear wave ultrasound elastography can provide useful quantitative information on the mechanical properties of the spastic muscles in post-stroke patients. Nevertheless, new studies using common terminology and parameters are needed to develop reliable methods that could help in assessing treatment efficiency.

A Delphi-Based Consensus Statement on the Management of Anticoagulated Patients With Botulinum Toxin for Limb Spasticity.

OBJECTIVE: To create a consensus statement on the considerations for treatment of anticoagulated patients with botulinum toxin A (BoNTA) intramuscular injections for limb spasticity. DESIGN: We used the Delphi method. SETTING: A multiquestion electronic survey. PARTICIPANTS: Canadian physicians (N=39) who use BoNTA injections for spasticity management in their practice. INTERVENTIONS: After the survey was sent, there were e-mail discussions to facilitate an understanding of the issues underlying the responses. Consensus for each question was reached when agreement level was ≥75%. MAIN OUTCOME MEASURES: Not applicable. RESULTS: When injecting BoNTA in anticoagulated patients: (1) BoNTA injections should not be withheld regardless of muscles injected; (2) a 25G or smaller size needle should be used when injecting into the deep leg compartment muscles; (3) international normalized ratio (INR) level should be ≤3.5 when injecting the deep leg compartment muscles; (4) if there are clinical concerns such as history of a fluctuating INR, recent bleeding, excessive or new bruising, then an INR value on the day of injection with point-of-care testing or within the preceding 2-3 days should be taken into consideration when injecting deep compartment muscles; (5) the concern regarding bleeding when using direct oral anticoagulants (DOACs) should be the same as with warfarin (when INR is in the therapeutic range); (6) the dose and scheduling of DOACs should not be altered for the purpose of minimizing the risk of bleeding prior to BoNTA injections. CONCLUSIONS: These consensus statements provide a framework for physicians to consider when injecting BoNTA for spasticity in anticoagulated patients. These consensus statements are not strict guidelines or decision-making steps, but rather an effort to generate common understanding in the absence of evidence in the literature.