Drugs & Medication

The Canada Dry brand of tonic water, shown on the right under ultraviolet light.

Tonic water (or Indian tonic water) is a carbonated soft drink flavoured with quinine. The drink gains its name from the medicinal effects of this slightly bitter flavouring.

The quinine was added to the drink as a prophylactic against malaria, since it was originally intended for consumption in tropical areas of India and Africa where that disease is endemic.

Tonic water originally contained only carbonated water and quinine, and it contained a large amount of the latter. However, most tonic water today contains a medically insignificant amount of quinine, and is thus used for its flavor only. It is consequently less bitter, and is also usually sweetened. Some manufacturers also produce diet tonic water.

In the United States, the Food and Drug Administration limits tonic water quinine to 83 ppm (83 mg per litre if calculated by mass), which is one-half to one-quarter the concentration used in therapeutic tonic.

Tonic water is often used as a mixer for alcoholic spirits, especially gin (the mixture commonly known as a gin and tonic).

Tonic water with lemon or lime flavor added is known as bitter lemon or bitter lime, respectively. Such soft drinks are more popular in Europe than in the United States.

Tonic water will glow under ultraviolet light, due to the quinine in it.

Brands of tonic water:

• Canada Dry
  Cantrell
  Cunnington
  Seagram's
  Schweppes
  Royal Club
  Nordic Mist by Coca-Cola Company
  Kinley by Coca-Cola Company
  Krest by Coca-Cola Company
  Antarctica by Ambev (Brazil)
  Schin Tonica, made by Schincariol (Brazil)
  Finches by Gleeson (Ireland)
  Paso de los Toros by PepsiCo Inc. (Uruguay)