Opioids may be given by mouth (oral), by injection into a muscle (intramuscular) or by injection into a vein (intravascular). Opioids can also be given through an epidural or by spinal injection.
Although opioids are similar drugs, some may work better than other depending on how they are given. For example, research has shown that women who receive an injection of diamorphine into a muscle are more likely to be satisfied with their analgesia (pain relief) when compared to when pethidine is used for the injection.
Facts about opioids:
- A midwife usually gives opioids during labour by injecting them into a large muscle in your arm or leg.
- The pain relief is often limited. You will start to feel the effects after about half an hour and they may last a few hours.
- Opioids are less effective at easing pain in labour than Entonox (gas and air).
- Although pain relief may be limited, some women say it makes them feel more relaxed and less worried about the pain.
- Other women are disappointed with the effect of opioids on their pain and say they feel less in control.