Bupivakaiini

Bupivakaiini, known in English as bupivacaine, is a long-acting amide local anesthetic used to produce regional anesthesia and postoperative analgesia. It acts by reversibly blocking voltage-gated sodium channels in nerve membranes, thereby preventing depolarization and the transmission of nerve impulses.

Clinical use includes epidural, intrathecal (spinal), peripheral nerve blocks, and local infiltration. Its long duration of action makes it suitable for procedures requiring extended analgesia, such as certain surgeries and obstetric labor analgesia when used in appropriate regional techniques. The onset of anesthesia is relatively gradual compared with shorter-acting agents and depends on concentration, site, and route of administration.

Safety and adverse effects are dominated by the possibility of systemic toxicity, particularly with intravascular injection or high doses. Early signs of toxicity include circumoral numbness, dizziness, tinnitus, and blurred vision, potentially progressing to seizures, arrhythmias, and cardiac arrest. The racemic mixture carries a higher cardiotoxic risk than the single-enantiomer formulation levobupivacaine, which has a more favorable safety profile in some settings.

Pharmacokinetics-wise, bupivacaine is metabolized in the liver by hepatic enzymes and is excreted mainly via the kidneys. Dose planning should consider the site, presence of epinephrine (which can prolong duration by reducing systemic absorption), patient comorbidities, and pregnancy status when used for obstetric analgesia.

In practice, careful dosing, incremental administration, and continuous monitoring are essential to minimize toxicity while achieving effective regional anesthesia.