Quinazolinones

Methaqualone is a sedative-hypnotic medication that was widely prescribed during the mid-20th century. It was marketed under various brand names, including Quaalude ( ) and Sopor, typically containing 300 mg of methaqualone per tablet. A combination drug known as Mandrax was sold primarily in Europe, containing 250 mg of methaqualone and 20 mg of diphenhydramine in a single tablet.

Metolazone is a thiazide-like diuretic marketed under the brand names Zytanix, Metoz, Zaroxolyn, and Mykrox. It is primarily used to treat congestive heart failure and high blood pressure. Metolazone indirectly decreases the amount of water reabsorbed into the bloodstream by the kidney, so that blood volume decreases and urine volume increases. This lowers blood pressure and prevents excess fluid accumulation in heart failure. Metolazone is sometimes used together with loop diuretics such as furosemide or bumetanide, but these highly effective combinations can lead to dehydration and electroly

Ketanserin, sold under the brand name Sufrexal, is an antihypertensive agent which is used to treat arterial hypertension and vasospastic disorders. It is also used in scientific research as an antiserotonergic agent in the study of the serotonin system; specifically, the 5-HT2 receptor family. The drug is taken orally.

Quinazolinone is a heterocyclic chemical compound, a quinazoline with a carbonyl group in the C4N2 ring. Two isomers are possible: 2-quinazolinone and 4-quinazolinone, with the 4-isomer being the more common. These compounds are of interest in medicinal chemistry. File:2-Quinazolinone.png|2-Quinazolinone File:4-Quinazolinone.png|4-Quinazolinone

Mecloqualone (Nubarene, Casfen) is a quinazolinone-class GABAergic and is an analogue of methaqualone that was first made in 1960 and marketed mainly in France and some other European countries. It has sedative, hypnotic, and anxiolytic properties caused by its agonist activity at the β subtype of the GABAa receptor, and was used for the treatment of insomnia. Mecloqualone is faster-acting but shorter-lasting than methaqualone and so was used only as a sleeping pill, in contrast to methaqualone, which was used as a general-purpose anxiolytic as well. Mecloqualone was never as widely used as me

Cloroqualone is a quinazolinone-class GABAergic and is an analogue of methaqualone developed in the 1980s and marketed mainly in France and some other European countries. It has sedative and antitussive properties resulting from its agonist activity at the β subtype of the GABAa receptor and sigma-1 receptor, and was sold either alone or in combination with other ingredients as a cough medicine. Cloroqualone has weaker sedative properties than methaqualone and was sold for its useful cough-suppressing effects, but was withdrawn from the French market in 1994 because of concerns about its poten

Nitromethaqualone is an analogue of methaqualone that has similar sedative and hypnotic properties. It is significantly more potent (10×) compared to the parent compound; the typical dose is approximately 25 mg.

Afloqualone (Arofuto) is a quinazolinone family GABAergic drug and is an analogue of methaqualone developed in the 1970s by a team at Tanabe Seiyaku. It has sedative and muscle-relaxant effects resulting from its agonist activity at the β subtype of the GABAa receptor and has had some clinical use, although it causes photosensitization as a side-effect that can cause skin problems such as dermatitis.

Methylmethaqualone (MMQ) is a quinazolinone and an analogue of methaqualone that has similar sedative and hypnotic properties to its parent compound (resulting from its agonist activity at the β subtype of the GABAA receptor) and is around 3 times as potent in animal models. Methylmethaqualone differs from methaqualone by 4-methylation on the phenyl ring. It was made illegal in Germany in 1999 and listed by the DEA as a "drug of forensic interest" at about the same time, but little other information is available. It would appear that this compound was sold on the black market in Germany as a d

SL-164, also known as dicloqualone or DCQ, is an analogue of methaqualone developed in the late 1960s by a team at Sumitomo. SL-164 has similar sedative, hypnotic and properties to the parent compound, but was never marketed for clinical use, due to higher risk of convulsions. Like other 4-substituted analogues, such as methylmethaqualone, SL-164 may cause seizures.

Quinethazone (INN, brand name Hydromox) is a thiazide-like diuretic used to treat hypertension. Common side effects include dizziness, dry mouth, nausea, and low potassium levels.

Raltitrexed (Thaltitrexed, Tomudex, TDX, ZD 1694) is an antimetabolite drug used in cancer chemotherapy. It is an inhibitor of thymidylate synthase, and is manufactured by AstraZeneca.

Etaqualone (Aolan, Athinazone, Ethinazone) is a quinazolinone-class GABAergic and is an analogue of methaqualone that was developed in the 1960s. It was primarily marketed in France and other European countries, as well as later in China, where it is still used clinically as of 2022. It has sedative, hypnotic, muscle relaxant and central nervous system depressant properties resulting from its agonist activity at the β-subtype of the GABAA receptor, and was used for the treatment of insomnia.

Mebroqualone (MBQ) is a quinazolinone-class GABAergic and is an analogue of mecloqualone that has similar sedative and hypnotic properties to its parent compound, resulting from its agonist activity at the β subtype of the GABAa receptor. It was originally synthesized in the 1960s Mebroqualone differs from mecloqualone by having a bromine atom instead of a chlorine on the 3-phenyl ring. It was made illegal in Germany in 1998 but little other information is available. It would appear that this compound was sold on the black market in Germany as a designer drug analogue of mecloqualone.

Diproqualone is a quinazolinone class GABAergic and is an analogue of methaqualone developed in the late 1950s by a team at Nogentaise de Produits Chimique. It was marketed primarily in France and some other European countries. It has sedative, anxiolytic, antihistamine and analgesic properties, resulting from its agonist activity at the β subtype of the GABAa receptor, antagonist activity at all histamine receptors, inhibition of the cyclooxygenase-1 enzyme, and possibly its agonist activity at both the sigma-1 receptor and sigma-2 receptor (the function of these receptors and their clinical

Febrifugine is a quinazolinone alkaloid first isolated from the Chinese herb Dichroa febrifuga, but also found in the garden plant Hydrangea. Laboratory synthesis of febrifugine determined that the originally reported stereochemistry was incorrect.

Proquazone is a nonsteroidal anti-inflammatory drug, known as an NSAID.

Halofuginone, sold under the brand name Halocur, is a coccidiostat used in veterinary medicine. It is a synthetic halogenated derivative of febrifugine, a natural quinazolinone alkaloid which can be found in the Chinese herb Dichroa febrifuga (Chang Shan). Collgard Biopharmaceuticals is developing halofuginone for the treatment of scleroderma and it has received orphan drug designation from the U.S. Food and Drug Administration.