To help prevent pain during the final stages of childbirth, before the cutting or stitching of the perineum (skin between the vagina and anus).During general anesthesia to prevent coughing.To help prevent pain and or discomfort during dental procedures (e.g., prior to an injection).To help prevent pain associated with minor surgical procedures in the ear, nose and throat.Xynova Endo is a topical anesthetic used for the following purposes. The administered lidocaine subsequently spreads rapidly through the surrounding tissues and the anesthetic effect lasts approximately ten to twenty minutes when given intravenously and about sixty to ninety minutes after intramuscular injection. This rapid onset of action is demonstrated in about one minute following intravenous injection and fifteen minutes following intramuscular injection. As a result, about 25% of lidocaine molecules will be un-ionized and available at the physiological pH of 7.4 to translocate inside nerve cells, which means lidocaine elicits an onset of action more rapidly than other local anesthetics that have higher pKa values. Moreover, lidocaine possesses a dissociation constant (pKa) of 7.7 and is considered a weak base. Subsequently, in cardiac myocytes, lidocaine can potentially block or otherwise slow the rise of cardiac action potentials and their associated cardiac myocyte contractions, resulting in possible effects like hypotension, bradycardia, myocardial depression, cardiac arrhythmias, and perhaps cardiac arrest or circulatory collapse. In particular, such cardiac effects are likely associated with the principal effect that lidocaine elicits when it binds and blocks sodium channels, inhibiting the ionic fluxes required for the initiation and conduction of electrical action potential impulses necessary to facilitate muscle contraction. The net effect is normally a modest hypotension when the recommended dosages are not exceeded. With central neural blockade these changes may be attributable to the block of autonomic fibers, a direct depressant effect of the local anesthetic agent on various components of the cardiovascular system, and/or the beta-adrenergic receptor stimulating action of epinephrine when present. Duration of action potential and effective refractory period are also reduced.Įxcessive blood levels of lidocaine can cause changes in cardiac output, total peripheral resistance, and mean arterial pressure. In the heart, lidocaine reduces depolarisation of the ventricles during diastole and automaticity in the His-Purkinje system. It stabilises the neuronal membrane and inhibits Na ion movements, which are necessary for conduction of impulses. Xynova Endo is an amide type local anaesth.
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