Bupivacaine is a pharmacological agent that belongs to the category of anesthetics. The drug bupivacaine represents a local anesthetic and thereby belongs to the so-called amide type. The active ingredient is used, among other things, as a racemate. Bupivacaine is characterized by a comparatively slow onset of action. In addition, the effect of the drug lasts relatively long with a duration of up to twelve hours.
What is bupivacaine?
The drug bupivacaine is primarily used in the context of local anesthesia as well as anesthesia of complete body areas. In this context, it is used in conduction anesthesia and infiltration anesthesia. In conduction anesthesia, nerve cords are anesthetized, while in infiltration anesthesia, the active ingredient bupivacaine is injected into the tissue to locally relieve pain. The drug bupivacaine is also used in pain therapy. In addition, the active substance is used to switch off the sympathetic nerve, as pain associated with this nerve can thus be reduced. Unlike the active ingredients mepivacaine and lidocaine, the drug bupivacaine is lipophilic. If it enters the blood, 96 percent of the active ingredient binds to certain plasma proteins. In principle, the drug takes relatively long to take effect. The average plasma half-life is around five and a half hours. For this reason, bupivacaine is able to act for up to twelve hours. Subsequently, the active substance is excreted by the kidneys.
Pharmacologic action
The drug bupivacaine has a characteristic mode of action in the human organism. First, the drug induces a change in the permeability of cell membranes. This change is especially relevant for sodium ions. As a consequence, these ions are no longer able to flow into the cell, which is why no action potential can be formed. Consequently, pain can no longer be felt in the corresponding area. First and foremost, the active ingredient bupivacaine is a drug for local anesthesia. The substance blocks nerve fibers in the autonomic nervous system over a longer period of time, whereby the blockade is not permanent but reversible. In addition, the active ingredient is able to temporarily switch off specific sensory nerves and those controlling movements. Even those nerve fibers that control the activity of the heart, the drug bupivacaine can numb. The action of the drug bupivacaine is believed to be achieved by blocking the channels for sodium ions within the nerve cell walls. This is because the influx of these ions plays an important role in the electrical reversal of polarity in the nerves, which is what makes conduction of stimuli possible in the first place. Dense sodium channels do not allow corresponding ions into the nerve cell, so that no build-up of electrical voltage can take place. In the majority of cases, the active ingredient bupivacaine occurs in the form of bupivacaine hydrochloride, a salt. In this state, the drug first reaches the nerve cell and exerts its effect there. If the environment is very acidic, as is the case with inflamed areas, there is no cleavage of bupivacaine hydrochloride into its two basic components. For this reason, no analgesic effect is possible in such a case.
Medical application and use
The drug bupivacaine is primarily used in the context of anesthesia. In this context, it is used primarily for those anesthetic procedures that are located near the spinal cord. These include, for example, peridural or spinal anesthesia. Due to its relatively long-lasting effect, the drug bupivacaine is a very frequently used local anesthetic. In contrast, it tends to be used less frequently in dentistry. Here it is used primarily for very long treatments. Bupivacaine is also used in conduction and infiltration anesthesia. In principle, the active ingredient is suitable for the temporary elimination of severe to very severe pain in various areas of the body.
Risks and side effects
The drug bupivacaine has undesirable side effects that should be considered before using the agent. Basically, it should be noted that bupivacaine is a very toxic local anesthetic.This toxicity becomes particularly problematic with uncontrolled intravenous injection. Possible side effects and complaints of the drug bupivacaine include, for example, dizziness as well as hypotension or hypertension. In some circumstances, affected patients may suffer from nausea and vomiting. More serious side effects include cardiac arrhythmias or bradycardia. Palpitations are also possible while taking the drug. In some cases, patients experience convulsions. In addition, disturbances of hearing and vision as well as speech disorders are possible. Hypersensitivity reactions to bupivacaine are also sometimes seen, manifested for example in diarrhea or asthma attacks. In certain cases, administration of the active substance bupivacaine is contraindicated. This includes, for example, an existing hypersensitivity to so-called acid amides. If possible, the drug should also not be used in cases of low blood pressure (hypotension) or decompensated heart failure. Other contraindications include, for example, blood clotting disorders, hypovolemia, and increased intracranial pressure during peridural anesthesia.
