Epidurals Don't Last Forever — Here's When Yours Will Wear Off

Few things in life are as frightful as childbirth. I remember knowing from day one of pregnancy that I'd need an epidural. By day two, I was worrying that the anesthetic wouldn't take. How long would the medication take to kick in? And how long does it take an epidural to wear off? Such questions are popular on forum communities like Baby Center for a reason, and knowing the answers to such questions may soothe, if not entirely eliminate, any pre-childbirth nightmares. Yes, the pain of giving birth is serious — luckily, so is the anesthesia.

How long your epidural pain relief lasts depends on what kind of medication the doctors use. According to Dr. Jamil Abdur-Rahman, MD, OB-GYN and clinical instructor at Rosalind Franklin University's Chicago Medical School, most physicians combine a local anesthetic like Lidocaine or Bupivacaine with an opioid, like morphine, Demerol, or Fentanyl. "Each of these medications has a different time of onset," Abdur-Rahman tells Romper. While Lidocaine kicks in almost immediately, it also wears off in an hour. On the other hand, Bupivacaine requires 30 to 45 minutes to work, but can then last between 120 and 240 minutes. The same goes for the opioid medications in the mix, with Fentanyl and Demerol catching on quickly, and morphine requiring a full episode of The Wire before it kicks in. As with the locals, the medication that takes longer to start helping you out is also the one that lasts.

"As a general rule, the longer the time to onset of pain relief, the longer the epidural will be effective at relieving pain," Abdur-Rahman notes. Regardless of the cocktail you receive, most epidurals take between 10 and 30 minutes to provide relief. Again, depending on the drugs, they can last anywhere from one hour to a full day. "Typically though, most epidurals only need to be re-dosed once every three to four hours," he writes.

During my pregnancy, I worried a lot about becoming an epidural cautionary tale. What if my spine was too weird? What if it only took on one side? According to Abdur-Rahman, your metabolism also has something to do with how quickly the epidural wears off. "There are a number of factors that can cause people to metabolize both local anesthetics and opioid pain medications more quickly than others," he observes.

One such factor is called "anesthetic resistance," caused by a genetic mutation that accelerates the metabolism of local anesthetics. According to the Mother Nature Network, the mutation that causes anesthetic resistance is rare. Additionally, local anesthetics are metabolized by the liver, and some people who take other medications broken down by the same organ will metabolize the local anesthetics more quickly. Finally, regular opiate use as a result of chronic pain or addiction can also shorten the relief you experience from the heavy-hitters in an epidural.

While all this sounds scarily unpredictable, the truth is that doctors and nurses will try their darndest to control your pain and adjust the dose of your epidural accordingly. Deena Blumenfeld, pregnancy and childbirth expert with Shining Light Prenatal, explains to Romper in an email interview that pain medication is first given as an "initial bolus," or large single dose, and then becomes a steady drip. "Mothers can click a button up to four times an hour to add more medication," she writes. "So, the pain relief is constant." If the pain isn't well controlled, doctors may administer an additional bolus.

"Every woman's body is different," Blumenfeld writes, pointing out that metabolism isn't the only factor that might determine the dose you need. "After the epidural is inserted, if the mother compresses the tubing in her spine by how she is lying in bed, it will reduce the medication supply as well."

Luckily, an entire team of medical professionals will be there to ensure that your epidural does its job. Childbirth is uncomfortable, of course, but you don't have to experience the excruciating misery of times gone by. An epidural that wears off too soon can always be re-dosed, and I find it amazing that morphine can relieve pain for a full day. Whatever combination of medications you receive, help is right there in the birthing room. If you feel something, say something.

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