About an unusual case: GC-MS detection of lidocaine

Local anesthetics (LAs) are drugs that induce a temporary loss of sensation in a limited body area, preventing pain. Cocaine was the first local anesthetic discovered in the late 19th century. Cocaine is a benzoic acid ester obtained from the leaves of coca shrubs and was often used for its psychotropic effects. Cocaine was first isolated in 1860 by Albert Niemann. Sigmund Freud studied the physiological actions of cocaine. Carl Koller later introduced it into clinical practice in 1884 as a...

Local anesthetics (LAs) block sensory and motor impulses by inhibiting the sodium channels on the nerve cell membranes. This induces temporary loss of sensation, relieving pain in a specific body area.
Local anesthetics are amphiphilic molecules consisting of a hydrophobic aromatic part linked to a hydrophilic group by an ester or amide linkage. They are weak bases and are usually available as salts, which increases their solubility and stability. Once administered, LAs exist in the body either...

Depolarizing blockers are administered through intravenous injection. Succinylcholine is the most common choice of depolarizing blockers in emergency clinical practices. Although they have a rapid onset, they readily diffuse away from the motor end plate into the extracellular fluid. They are metabolized by enzymes such as liver butyrylcholinesterase and plasma pseudocholinesterases. This produces a short duration of action, typically 5-10 minutes long, unlike nondepolarizing blockers, which...

Local anesthetics (LAs) block the sodium channels of nerve trunks, sensory nerve endings, and neuromuscular junctions. Although LAs can block all kinds of nerves, the sensitivity of nerve fibers differs according to nerve types and structures. LAs are known to block myelinated fibers faster than unmyelinated ones. Also, they block pain or sensory neurons at low concentrations without affecting the motor neurons involved in muscle contractions. This helps relieve labor pain without affecting the...

Different methods, such as visual observance of metal-ion indicators, spectroscopic techniques, and potentiometric methods, can determine the endpoint of an EDTA titration.
In the visual method, metal-ion indicators (metallochromic dyes), which have distinct colors in their free and complex forms, are added to the mixture to signal the titration's end point. They form stable complexes with metal ions, but these complexes are weaker than the corresponding metal–EDTA complexes. As a result, EDTA...

Depending on the target organ, local anesthetics (LAs) can be administered via various routes. In surface anesthesia, LAs are applied directly to the surface of the skin or mucous membranes. It is widely used for topical skin numbing before venipuncture or minor surgical procedures. Commonly used surface local anesthetics are lidocaine or benzocaine sprays or creams. Surface anesthesia occurs within 5 minutes and lasts for about 60 minutes. One of the main disadvantages of topical anesthesia is...