Analgin® is a brand name for Metamizole sodium, a medication used to treat a variety of pains. It is also known as Dipyrone, Algopyrin, Algocalmin, Melubrin, and Novalgin. The drug was first synthesized in Germany in 1920, and it entered mass production two years later.

Analgin® is referred to as an analgesic and an antipyretic. This means that it is designed as a painkiller and a fever reducer, respectively. The drug is available as a 500-milligram tablet, or a solution for injection that comes in a 2 ml or 5 ml vial.

Besides fever, Analgin® is used to treat toothache and headache. Other ailments include arthralgia, which involves pain of the joints; neuralgia, which is pain in one or more nerves; and myositis, which concerns inflammation of the muscles. The injection form of Analgin® is used for reducing acute or severe pain resulting from operations, traumas, or neoplastic diseases, which is a group of medical conditions that involve the abnormal proliferation of cells.

Analgin® is usually taken according to the age group of the patient, as well as the severity of the pain. Adults can take up to two tablets at a frequency of two or three times a day. Children are generally allowed just one tablet within the same time frame. In cases of persistent pain, the dose can be taken up to four times a day, which is equivalent to taking the drug every six hours. The maximum daily dose, however, should be no more than 4 grams.

For five decades after its introduction, Analgin® was widely available across the world. A side effect of the medication, however, caused major concern. Scientists discovered that the drug could heighten the risk of agranulocytosis, a medical condition that involves a lowered white blood cell count, thus weakening the immune system's ability to fight diseases. In 1974, Sweden was the first country in the world to ban the drug, with the United States following suit in 1977. Since then, more than 30 countries, including Australia, Japan, Iran and several European nations, have either restricted the use of Analgin® to prescription use, or banned it altogether.

Analgin®, however, is still available as an over-the-counter drug in other countries, most notably in Latin America. In 2001, a 4-year-old immigrant boy from Mexico was admitted to a clinic in Salt Lake City, Utah, with agranulocytosis symptoms. This was due to the high availability of Analgin® among Mexican immigrants and Latino-owned shops.