Narcotic Pain Medications

Opioid analgesics, or narcotics, are a class of pain medications which includes many different drugs with different strengths, speed of onset, durations, and side effects. They are usually used to treat moderate to severe pain.

The following information about the use of narcotic medications for pain relief in labour will assist you to make an informed decision that is in line with your preferences and values. It’s important to learn about the benefits, risks and alternatives and to have a discussion with your healthcare provider to answer any questions before labour begins.

• May provide some pain relief⁴, dulls the pain, but doesn't remove it entirely⁶
• May help you relax⁴
• May be administered quickly

Risks for you:

• Sleepiness/drowsiness^{1 2} – this may make it more difficult to engage in decision making about your care³ and decrease your ability to safely move around on your own, limiting your mobility³

• Nausea (feeling sick to your stomach) and vomiting (throwing up)^{1 2 3 5 6}

• Dizziness/weakness^{1 5}

• Hallucinations (seeing or experiencing something that is not there)⁵

• Low blood pressure⁵

• Fast or slow heart rate⁵

• Respiratory depression (slowed or shallow breathing)^{3 6}

Risks for your baby:

• Variations in fetal heart rate during labour^{3 5 6}

• Fetal or newborn sedation (sleepiness) that may last several days^{2 6}

• Short-term respiratory depression (slow or shallow breathing)^{1 2 5 6}

• Delayed start and/or challenges with breastfeeding (related to inhibited sucking at breast and decreased alertness)^{2 3 5 6}

Please note that all narcotics cross the placenta and take more time to get out of the baby’s circulation than the mothers.  There is an increased need to assess the baby at birth. The Neonatal Intensive Care Unit (NICU) Team will be called to the birth if the baby shows signs of needing respiratory assistance (help with breathing) or if the narcotic was given within 4 hours of birth.

Alternatives

There are a variety of coping techniques you can use to manage the pain you experience during labour. Comfort measures do not involve the use of medications for pain relief. They allow you to have a better sense of control, and can result in a shorter labour with fewer medical interventions. Using comfort measures to avoid unnecessary interventions also supports your birth hormones. This will help you to have a labour that feels less intense and progresses more quickly. It also sets you up for better breastfeeding success. There is also no risk for you or your baby. See our Comfort Measures webpage for more information.

Procedure

Narcotics can be given by an intramuscular (IM) injection or an intravenous (IV) infusion. The route is often determined by the type of narcotic as well as the stage of labour. For both of these methods of providing the medication, you and your baby will be monitored closely. You may also have continuous fetal monitoring if there are concerns about the fetal heart rate. This may restrict your movement. The Neonatal Intensive Care Team will be called to attend your birth and provide care if the baby shows signs of needing assistance.

Intramuscular Injections

During labour, you can receive narcotics for pain relief by an injection given in your upper arm muscle, upper thigh muscle, or gluteal (buttock) muscle. This is called an intramuscular (IM) injection. This form of medication will last from 2 to 4 hours.
Advantages of receiving pain medication by an IM injection include:

• Can be given quickly
• No need for an Intravenous (IV) line

Disadvantages of receiving pain medication by an IM injection include:

• Delayed pain relief compared to intravenous (IV) infusion
• The need for high doses of medication⁶
• An unpredictable rate of release of medication from muscle tissue that can result in uneven distribution of the medication
• The inability to give medication close to birth with this method. There may not be enough time for the medication to get out of the baby’s circulation before birth, this can lead to sedation (sleepiness) and/or respiratory depression (slowed or shallow breathing).

Intravenous Infusion

During labour, you can receive narcotics for pain relief by Intravenous (IV) infusion called patient-controlled analgesia (PCA). For this, an IV pump is programmed to allow you to push a button to give yourself a small dose of a narcotic (e.g., fentanyl) when needed. Most of the time there is also a constant, small amount of medication given and you top this up as needed. An IV PCA allows you to have more control of pain management during labour. It is also sometimes reserved for women who cannot get an epidural.
Advantages of receiving pain medication by IV (compared to IM) include:

• Starts working sooner than intramuscular (IM) injections
• Smaller doses of medication
• A more predictable effect

Disadvantages of receiving pain medication via an IV, (compared to IM) include:

• Restricted movement due to the IV set-up.

For more information, decision aids & tools:

• Ottawa Family Decision Guide
• Making Informed Decisions About Your Care - other decision aids & tools

If you have specific questions:

• Speak with your healthcare provider

• If you are giving birth at LHSC – speak with the nurse at the London Health Sciences Centre (LHSC) Preadmission Clinic.