Many patients who neither want or need regional anesthesia techniques (intrathecal, epidural) find that medications given intravenously are a good option for the partial relief of their labor pain.

What do I mean by partial relief? Medications given this way provide analgesia - that is, they provide pain reduction. They do not cause numbness and therefore they do not provide complete absence of sensation from contractions. The amount of analgesia is limited by the side effects that occur with increasing dosages.

There are many different types of medication that can be used intravenously. In fact, there are five common categories of medications that you might encounter. The most commonly used of these are the narcotics and they are generally considered the most effective. Therefore, this class of drugs is what we will discuss here.

The narcotic family includes drugs that you might have heard of such as Demerol, Fentanyl, Stadol (butorphanol) and Nubain. These medications are all derived from or similar to morphine, the original narcotic.

Narcotics represent one of the most powerful classes of analgesic medications that are available to us. As I mentioned before, the amount of pain relief that you can get from narcotics is limited only by the side effects that they cause.

Said another way, these drugs are able to give complete analgesia (pain relief) but often only at the expense of problems with breathing, low blood pressure, excessive sedation, etc. Obviously, this is not a desirable state for the mother or the baby. As a result, narcotics are utilized to reduce the pain associated with labor, not eliminate it. All the narcotics can reduce pain - the choice of which one to use is based on speed of onset, duration of action and side effects associated with the drug.

It is important to note that when medications are given intravenously they go directly into the bloodstream of the mother. Narcotics in the bloodstream do cross the placenta and thus are present to some extent in the bloodstream of the fetus. As a result, narcotics have the potential to depress the fetus in differing degrees.

How much depression actually occurs depends on the drug chosen, the route by which it is administered, the timing of administration with regards to delivery of the baby and the presence of other obstetric complications.

Pros:

• Easily and quickly administered
• Does not require an anesthesiologist to be present
• Can be given to patients that do not want or cannot have a regional anesthetic (like an epidural or intrathecal)
• Not as invasive as other techniques such as epidural or intrathecal
• Can be used for initial pain relief without ruling out other options should they become necessary (you don't lose the ability to have an epidural or intrathecal later if you change your mind)
• Can be given early in labor without significant slowing of labor
• Can be administered by patient controlled devices returning some measure of control to the patient

Cons:

• Crosses the placenta and can cause fetal depression
• Can cause side effects in the mother (sedation, breathing problems, low blood pressure, itching, nausea, vomiting, urinary retention, constipation, etc.) - these are more common as more medication is given
• Amount of pain relief is limited by the occurrence of side effects