Quaternium-15, a preservative, is one of the most used substances and is added to several cosmetics and other industrial products. Quaternium-15 is a mixture of isomers, where the cis-form is the dominant form and where the trans-form is the minor component present as an impurity. Quaternium-15 can be found under a variety of names, most commonly those of the Dow Chemical Company: Dowicil 200 (cis isomer only), Dowicil 75 and Dowicil 100 (both a mix of cis and trans isomers). The isolated cis-compound is used primarily in cosmetic applications, with a maximum permitted concentration in the EU of 0.2%. DOWICIL 200 preservative (cis form) is used primarily as a preservative in a wide variety of personal-care and cosmetic products. It is designed to provide highly effective broad-spectrum antimicrobial activity, especially in water-based formulations. It is used in both leave-on and rinse-off application such as baby-care products, hair-care products, lotions, powders, and creams. The mixed product (cis- and trans-) is used in a wider range of formulations such as: emulsifiable metal-cutting fluids; latex and emulsion paints; liquid floor polishes and floor waxes; glues and adhesives. Recently, the cis-form has been classified as a CMR substance with the classification toxic to reproduction, category 3. This classification only concerns the cis-isomer:

Terlipressin (Glypressin) is indicated for the treatment of bleeding oesophageal varices and in some countries for the treatment of hepatorenal syndrome type 1. It is a prodrug and is converted to the lysine vasopressin in the circulation after the N-triglycyl residue is cleaved by endothelial peptidases. This results in a ‘slow release’ of the vasoactive lysine vasopressin. Terlipressin exerts its action by activating V1a, V1b and V2 vasopressin receptors. On September 14, 2022, the FDA granted approval to terlipressin (Terlivaz) for the treatment of adults hospitalized with hepatorenal syndrome with rapid reduction in kidney function (HRS-1). Prior to the approval, no approved treatment for this condition existed in the United States.

Terlipressin (Glypressin) is indicated for the treatment of bleeding oesophageal varices and in some countries for the treatment of hepatorenal syndrome type 1. It is a prodrug and is converted to the lysine vasopressin in the circulation after the N-triglycyl residue is cleaved by endothelial peptidases. This results in a ‘slow release’ of the vasoactive lysine vasopressin. Terlipressin exerts its action by activating V1a, V1b and V2 vasopressin receptors. On September 14, 2022, the FDA granted approval to terlipressin (Terlivaz) for the treatment of adults hospitalized with hepatorenal syndrome with rapid reduction in kidney function (HRS-1). Prior to the approval, no approved treatment for this condition existed in the United States.

Dasiglucagon (Zegalogue®) is an antihypoglycaemic agent being developed by Zealand Pharma for the treatment of hypoglycaemia, type 1 diabetes mellitus (T1DM) management and congenital hyperinsulinism. Dasiglucagon is a glucagon receptor agonist, which increases blood glucose concentration by activating hepatic glucagon receptors, thereby stimulating glycogen breakdown and release of glucose from the liver. Hepatic stores of glycogen are necessary for dasiglucagon to produce an antihypoglycemic effect. In March 2021, dasiglucagon received its first approval in the USA for the treatment of severe hypoglycaemia in paediatric and adult patients with diabetes aged 6 years and above. Dasiglucagon, a glucagon analogue, is available as a single-dose autoinjector or prefilled syringe for subcutaneous injection.

Quinidine is a pharmaceutical agent that acts as a class I antiarrhythmic agent (Ia) in the heart. It is a stereoisomer of quinine, originally derived from the bark of the cinchona tree. The drug causes increased action potential duration, as well as a prolonged QT interval. Like all other class I antiarrhythmic agents, quinidine primarily works by blocking the fast inward sodium current (INa). Quinidine's effect on INa is known as a 'use-dependent block'. This means at higher heart rates, the block increases, while at lower heart rates, the block decreases. The effect of blocking the fast inward sodium current causes the phase 0 depolarization of the cardiac action potential to decrease (decreased Vmax). Quinidine also blocks the slowly inactivating, tetrodotoxin-sensitive Na current, the slow inward calcium current (ICA), the rapid (IKr) and slow (IKs) components of the delayed potassium rectifier current, the inward potassium rectifier current (IKI), the ATP-sensitive potassium channel (IKATP) and Ito. Quinidine is also an inhibitor of the cytochrome P450 enzyme 2D6 and can lead to increased blood levels of lidocaine, beta blockers, opioids, and some antidepressants. Quinidine also inhibits the transport protein P-glycoprotein and so can cause some peripherally acting drugs such as loperamide to have central nervous system side effects, such as respiratory depression if the two drugs are coadministered. Quinidine can cause thrombocytopenia, granulomatous hepatitis, myasthenia gravis, and torsades de pointes, so is not used much today. Torsades can occur after the first dose. Quinidine-induced thrombocytopenia (low platelet count) is mediated by the immune system and may lead to thrombocytic purpura. A combination of dextromethorphan and quinidine has been shown to alleviate symptoms of easy laughing and crying (pseudobulbar affect) in patients with amyotrophic lateral sclerosis and multiple sclerosis. This drug is marketed as Nuedexta in the United States. Intravenous quinidine is also indicated for the treatment of Plasmodium falciparum malaria. However, quinidine is not considered the first-line therapy for P. falciparum. The recommended treatments for P. falciparum malaria, according to the Toronto Notes 2008, are a combination of either quinine and doxycycline or atovaquone and proguanil (Malarone). The drug is also effective for the treatment of atrial fibrillation in horses.

Quinidine is a pharmaceutical agent that acts as a class I antiarrhythmic agent (Ia) in the heart. It is a stereoisomer of quinine, originally derived from the bark of the cinchona tree. The drug causes increased action potential duration, as well as a prolonged QT interval. Like all other class I antiarrhythmic agents, quinidine primarily works by blocking the fast inward sodium current (INa). Quinidine's effect on INa is known as a 'use-dependent block'. This means at higher heart rates, the block increases, while at lower heart rates, the block decreases. The effect of blocking the fast inward sodium current causes the phase 0 depolarization of the cardiac action potential to decrease (decreased Vmax). Quinidine also blocks the slowly inactivating, tetrodotoxin-sensitive Na current, the slow inward calcium current (ICA), the rapid (IKr) and slow (IKs) components of the delayed potassium rectifier current, the inward potassium rectifier current (IKI), the ATP-sensitive potassium channel (IKATP) and Ito. Quinidine is also an inhibitor of the cytochrome P450 enzyme 2D6 and can lead to increased blood levels of lidocaine, beta blockers, opioids, and some antidepressants. Quinidine also inhibits the transport protein P-glycoprotein and so can cause some peripherally acting drugs such as loperamide to have central nervous system side effects, such as respiratory depression if the two drugs are coadministered. Quinidine can cause thrombocytopenia, granulomatous hepatitis, myasthenia gravis, and torsades de pointes, so is not used much today. Torsades can occur after the first dose. Quinidine-induced thrombocytopenia (low platelet count) is mediated by the immune system and may lead to thrombocytic purpura. A combination of dextromethorphan and quinidine has been shown to alleviate symptoms of easy laughing and crying (pseudobulbar affect) in patients with amyotrophic lateral sclerosis and multiple sclerosis. This drug is marketed as Nuedexta in the United States. Intravenous quinidine is also indicated for the treatment of Plasmodium falciparum malaria. However, quinidine is not considered the first-line therapy for P. falciparum. The recommended treatments for P. falciparum malaria, according to the Toronto Notes 2008, are a combination of either quinine and doxycycline or atovaquone and proguanil (Malarone). The drug is also effective for the treatment of atrial fibrillation in horses.