Being able to achieve pain relief through chewing or ingesting Opium poppy seeds has been known about for centuries and is documented in Roman and Egyptian writings. The actual extract of morphine from the opium poppy was first discovered in 1806. This innovation enabled a specific, measured dose of the narcotic to be swallowed as a liquid. It was not until the syringe and needle were invented in Edinburgh in 1853 that morphine could then be given as an injection.
Morphine was first used for women in labour in the early 1900's. It was initially mixed with sedatives and injected into the woman's vein to produce what was called 'twilight sleep'. These drugs usually made the woman semiconscious (or totally unconscious), often forgetting the actual birth, as well as relieving pain.
The drug Pethidine (a synthetic form of morphine) was first discovered as an injection for pain relief in labour in Germany in 1939. Its use in labour became more widespread in the late 1940's, especially as it was something that a midwife could administer without calling a doctor in (like gas). Since this time, Pethidine has continued to be the narcotic drug of choice for labour pain relief worldwide. Although its popularity has declined in recent years, especially since the introduction of the
epidural.
Up until the 1960's, Pethidine was often given in extremely high doses (sometimes up to 500mg). Today the standard dose is around 50 to 150mg. Pethidine injections were also often mixed with other sedative drugs such as barbiturates or tranquillizers. Up until recent years the main drugs used were promazine (known as Sparine) or promethazine (known as Phenergan). These were given with the aim of reducing the nausea and vomiting that can be experienced as a side effect of the Pethidine, as well as increase the sedation of the woman.
Additional medications for sedation are rarely given during labour these days.