However, another study found no difference between racemic ketamine and esketamine on the patients level of vigilance. Interpretation of this finding is complicated by the fact that racemic ketamine is 50% esketamine. Pharmacokinetics
Esketamine is eliminated from the human body more quickly than arketamine (R(–)-ketamine) or racemic ketamine, although arketamine slows the elimination of esketamine. History
Esketamine was introduced for medical use as an anesthetic in Germany in 1997, and was subsequently marketed in other countries. In addition to its anesthetic effects, the medication showed properties of being a rapid-acting antidepressant, and was subsequently investigated for use as such. Esketamine received a breakthrough designation from the FDA for treatment-resistant depression (TRD) in 2013 and major depressive disorder (MDD) with accompanying suicidal ideation in 2016. In November 2017, it completed phase III clinical trials for treatment-resistant depression in the United States. Johnson & Johnson filed a Food and Drug Administration (FDA) New Drug Application (NDA) for approval on 4 September 2018; the application was endorsed by an FDA advisory panel on 12 February 2019, and on 5 March 2019, the FDA approved esketamine, in conjunction with an oral antidepressant, for the treatment of depression in adults. In August 2020, it was approved by the U.S. Food and Drug Administration (FDA) with the added indication for the short-term treatment of suicidal thoughts.Since the 1980s, closely associated ketamine has been used as a club drug also known as "Special K" for its trip-inducing side effects.
Flumazenil (also known as flumazepil, code name Ro 15-1788) is a selective GABAA receptor antagonist administered via injection, otic insertion, or intranasally. Therapeutically, it acts as both an antagonist and antidote to benzodiazepines (particularly in cases of overdose), through competitive inhibition. It was first characterized in 1981, and was first marketed in 1987 by Hoffmann-La Roche under the trade name Anexate. However, it did not receive FDA approval until December 20, 1991. The developer lost its exclusive patent rights in 2008; so at present, generic formulations of this drug are available. Intravenous flumazenil is primarily used to treat benzodiazepine overdoses and to help reverse anesthesia. Administration of flumazenil by sublingual lozenge and topical cream has also been tested. Medical uses
Flumazenil benefits patients who become excessively drowsy after use of benzodiazepines for either diagnostic or therapeutic procedures.The drug has been used as an antidote in the treatment of benzodiazepine overdoses. It reverses the effects of benzodiazepines by competitive inhibition at the benzodiazepine (BZ) recognition site on the GABA/benzodiazepine receptor complex. There are many complications that must be taken into consideration when used in the acute care setting. These include lowered seizure threshold, agitation, and anxiousness. Flumazenils short half-life requires multiple doses. Because of the potential risks of withdrawal symptoms and the drugs short half-life, patients must be carefully monitorered to prevent recurrence of overdose symptoms or adverse side effects. Flumazenil is also sometimes used after surgery to reverse the sedative effects of benzodiazepines.