Flecainide is a potent anti-arrhythmia agent, effective in a wide range of ventricular and atrial arrhythmias and tachycardias. Flecainide has local anesthetic activity and belongs to the membrane stabilizing (Class 1) group of antiarrhythmic agents; it has electrophysiologic effects characteristic of the IC class of antiarrhythmics. Flecainide acts on sodium channels on the neuronal cell membrane, limiting the spread of seizure activity and reducing seizure propagation. The antiarrhythmic actions are mediated through effects on sodium channels in Purkinje fibers. Flecainide is a sodium channel blocker, binding to voltage gated sodium channels. It stabilizes the neuronal membrane by inhibiting the ionic fluxes required for the initiation and conduction of impulses. Ventricular excitability is depressed and the stimulation threshold of the ventricle is increased during diastole. Flecainide is sold under the trade name Tambocor (manufactured by 3M pharmaceuticals). Flecainide went off-patent on February 10, 2004. In addition to being marketed as Tambocor, it is also available in generic version and under the trade names Almarytm, Apocard, Ecrinal, and Flécaine.

Bupivacaine is a widely used local anesthetic agent. Bupivacaine is often administered by spinal injection prior to total hip arthroplasty. It is also commonly injected into surgical wound sites to reduce pain for up to 20 hours after surgery. In comparison to other local anesthetics it has a long duration of action. It is also the most toxic to the heart when administered in large doses. Bupivacaine blocks the generation and the conduction of nerve impulses, presumably by increasing the threshold for electrical excitation in the nerve, by slowing the propagation of the nerve impulse, and by reducing the rate of rise of the action potential. Bupivacaine binds to the intracellular portion of sodium channels and blocks sodium influx into nerve cells, which prevents depolarization. In general, the progression of anesthesia is related to the diameter, myelination and conduction velocity of affected nerve fibers. The analgesic effects of bupivicaine are thought to potentially be due to its binding to the prostaglandin E2 receptors, subtype EP1 (PGE2EP1), which inhibits the production of prostaglandins, thereby reducing fever, inflammation, and hyperalgesia. Bupivacaine sometimes used in combination with epinephrine to prevent systemic absorption and extend the duration of action.

Lidocaine is a local anesthetic and cardiac depressant used to numb tissue in a specific area and for management of cardiac arrhythmias, particularly those of ventricular origins, such as occur with acute myocardial infarction. Lidocaine alters signal conduction in neurons by blocking the fast voltage-gated Na+ channels in the neuronal cell membrane responsible for signal propagation. With sufficient blockage, the membrane of the postsynaptic neuron will not depolarize and will thus fail to transmit an action potential. This creates the anesthetic effect by not merely preventing pain signals from propagating to the brain, but by stopping them before they begin. Careful titration allows for a high degree of selectivity in the blockage of sensory neurons, whereas higher concentrations also affect other modalities of neuron signaling. Lidocaine exerts an antiarrhythmic effect by increasing the electrical stimulation threshold of the ventricle during diastole. In usual therapeutic doses, lidocaine hydrochloride produces no change in myocardial contractility, in systemic arterial pressure, or an absolute refractory period. The efficacy profile of lidocaine as a local anesthetic is characterized by a rapid onset of action and intermediate duration of efficacy. Therefore, lidocaine is suitable for infiltration, block, and surface anesthesia. Longer-acting substances such as bupivacaine are sometimes given preference for spinal and epidural anesthesias; lidocaine, though, has the advantage of a rapid onset of action. Lidocaine is also the most important class-1b antiarrhythmic drug; it is used intravenously for the treatment of ventricular arrhythmias (for acute myocardial infarction, digoxin poisoning, cardioversion, or cardiac catheterization) if amiodarone is not available or contraindicated. Lidocaine should be given for this indication after defibrillation, CPR, and vasopressors have been initiated. A routine preventative dose is no longer recommended after a myocardial infarction as the overall benefit is not convincing. Inhaled lidocaine can be used as a cough suppressor acting peripherally to reduce the cough reflex. This application can be implemented as a safety and comfort measure for patients who have to be intubated, as it reduces the incidence of coughing and any tracheal damage it might cause when emerging from anesthesia. Adverse drug reactions (ADRs) are rare when lidocaine is used as a local anesthetic and is administered correctly. Most ADRs associated with lidocaine for anesthesia relate to administration technique (resulting in systemic exposure) or pharmacological effects of anesthesia, and allergic reactions only rarely occur. Systemic exposure to excessive quantities of lidocaine mainly result in a central nervous system (CNS) and cardiovascular effects – CNS effects usually occur at lower blood plasma concentrations and additional cardiovascular effects present at higher concentrations, though cardiovascular collapse may also occur with low concentrations.

(+)-SKF-10,047 is a sigma-opioid receptor agonist. (+)-SKF-10,047 is distinct from its (-)-enantiomer in binding pattern and associated behavioural effects. (+)-SKF-10,047 stress-induced motor suppression, while its (-)-optical isomer was inactive. Besides activation of sigma-1 receptor, (+)-SKF-10,047 is inhibitor of Na(V)1.2 and Na(V)1.4 channels.

CO-102862, also known as V102862, is a potent, broad-spectrum state-dependent blocker of mammalian voltage-gated sodium channels. A key feature of the mechanism of inhibition is that V102862 has up to 80-fold higher affinity for inactivated Na channels as compared to channels in resting states. V102862 is an orally active anticonvulsant with robust activity in a variety of rodent models of epilepsy.

Veratridine (VTD), an alkaloid derived from the Liliaceae plant shows anti-tumor effects. Veratridine is also an agent that opens voltage dependent Na+ channels, blocks Na+ channel activation, and induces Ca2+ influx. The compound has been observed to be an alkaloid neurotoxin used to amplify sodium permeability. Studies report that Veratridine can trigger exocytosis and induce Ca2+ oscillations. Furthermore, Veratridine has been shown to effect the mitochondrial respiratory chain complexes, induce release of noradrenaline, and increase superoxide anion production. Veratridine competes with BTX binding in a mutually exclusive manner. However, the pharmacological effects of veratridine on Na+ channels are quite different from those of BTX. First, veratridine reduces the single Na+ channel conductance drastically whereas BTX does not. Veratridine therefore is regarded as a partial agonist and BTX as a full agonist of Na+ channels. Second, under voltage clamp conditions BTX binds practically irreversibly to Na+ channels whereas veratridine readily dissociates from its binding site. Both of these drugs, however, bind preferentially to the open state of Na+ channels. The BTX resistant Na+ channels in Phyllobates frogs remain sensitive to veratridine. The ceveratrum alkaloids, including Veratridine, have a characteristic hypotensive effect not directly involving the CNS. They slow the heart and lower arterial blood pressure by reflexly stimulating medullary vasomotor centers without decreasing cardiac output (Bezold–Jarisch effect). These agents were introduced in the 1950s as antihypertensive agents; however, they were found to have a narrow therapeutic index and their use was discontinued.

Levobupivacaine (CHIROCAINE®) is a (S)-enantiomer of bupivacaine and it is related chemically and pharmacologically to the amino amide class of local anesthetics. Local anesthetics block the generation and the conduction of nerve impulses by increasing the threshold for electrical excitation in the nerve, by slowing propagation of the nerve impulse, and by reducing the rate of rise of the action potential. In general, the progression of anesthesia is related to the diameter, myelination, and conduction velocity of affected nerve fibers. Clinically, the order of loss of nerve function is as follows: 1) pain, 2) temperature, 3) touch, 4) proprioception and 5) skeletal muscle tone. Levobupivacaine (CHIROCAINE®) is a safer alternative for regional anesthesia than bupivacaine. It demonstrated less affinity and strength of depressant effects onto myocardial and central nervous vital centers in pharmacodynamic studies, and a superior pharmacokinetic profile.

Alfaxalone is a rapidly acting hydrophobic synthetic neurosteroid. It is indicated for the induction and maintenance of anesthesia and for induction of anesthesia followed by maintenance with an inhalant anesthetic, in cats and dogs. Alfaxalone induces anaesthesia through activity at the gamma amino butyric acid sub-type A receptor (GABAA) present on cells in the Central Nervous System (CNS). Alfaxalone enhances the effects of GABA at the GABAA receptors resulting in opening of channels into the cells and an influx of chloride ions. This causes hyperpolarisation of the cells and inhibition of neural impulse transmission. Alfaxalone can be safely combined with premedicants (xylazine, (dex)medetomidine, acepromazine, midazolam), opioids (morphine, methadone, hydromorphone, butorphanol, nalbuphine, buprenorphine, fentanyl), and NSAIDs. Alfaxalone’s adverse reactions are: hypotension, tachycardia, apnea, hypertension, bradypnea and others.

Flecainide is a potent anti-arrhythmia agent, effective in a wide range of ventricular and atrial arrhythmias and tachycardias. Flecainide has local anesthetic activity and belongs to the membrane stabilizing (Class 1) group of antiarrhythmic agents; it has electrophysiologic effects characteristic of the IC class of antiarrhythmics. Flecainide acts on sodium channels on the neuronal cell membrane, limiting the spread of seizure activity and reducing seizure propagation. The antiarrhythmic actions are mediated through effects on sodium channels in Purkinje fibers. Flecainide is a sodium channel blocker, binding to voltage gated sodium channels. It stabilizes the neuronal membrane by inhibiting the ionic fluxes required for the initiation and conduction of impulses. Ventricular excitability is depressed and the stimulation threshold of the ventricle is increased during diastole. Flecainide is sold under the trade name Tambocor (manufactured by 3M pharmaceuticals). Flecainide went off-patent on February 10, 2004. In addition to being marketed as Tambocor, it is also available in generic version and under the trade names Almarytm, Apocard, Ecrinal, and Flécaine.

Bupivacaine is a widely used local anesthetic agent. Bupivacaine is often administered by spinal injection prior to total hip arthroplasty. It is also commonly injected into surgical wound sites to reduce pain for up to 20 hours after surgery. In comparison to other local anesthetics it has a long duration of action. It is also the most toxic to the heart when administered in large doses. Bupivacaine blocks the generation and the conduction of nerve impulses, presumably by increasing the threshold for electrical excitation in the nerve, by slowing the propagation of the nerve impulse, and by reducing the rate of rise of the action potential. Bupivacaine binds to the intracellular portion of sodium channels and blocks sodium influx into nerve cells, which prevents depolarization. In general, the progression of anesthesia is related to the diameter, myelination and conduction velocity of affected nerve fibers. The analgesic effects of bupivicaine are thought to potentially be due to its binding to the prostaglandin E2 receptors, subtype EP1 (PGE2EP1), which inhibits the production of prostaglandins, thereby reducing fever, inflammation, and hyperalgesia. Bupivacaine sometimes used in combination with epinephrine to prevent systemic absorption and extend the duration of action.