Antispasmodics vs. Painkillers: What's the Difference and When to Take Them

 7 mins 30 sec

Topic

  • Managing Abdominal Pain

Whether it’s just causing you discomfort or making you want to curl up in a ball, tummy pain is a nuisance, to say the least. But what’s the best medicine to get rid of it? Antispasmodics or painkillers?

Unlike painkillers, antispasmodics treat the root cause of pain by acting directly where they are needed in the gut. In other words, they work to alleviate the cramps and pain at the source itself. Meanwhile, painkillers simply cut signals to the brain, but do not specifically work on the site of pain and cramping.

Read on to find out how both of these drugs work, what they are used for, and some further key differences between them.

Painkillers: What are They and What Do They Do?

Painkillers (also called pain relievers, or analgesics) are medications used to treat and manage pain1. They include:

  • acetaminophen (also known as paracetamol)
  • nonsteroidal anti-inflammatory drugs (NSAIDs, such as ibuprofen or aspirin)
  • local anesthetics
  • opioids

Acetaminophen and NSAIDs are non-opioid painkillers that you can get over-the-counter (OTC), or without prescription. Opioids are prescribed by your doctor. Local anesthetics can be prescription or non-prescription depending on the specific medication.

OTC Painkillers: Uses

Paracetamol is used to treat mild and moderate pain, and to reduce fever1.

NSAIDs are used to1:

  • relieve mild or moderate pain
  • reduce fever
  • relieve pain associated with inflammation
  • reduce swelling2

Paracetamol or NSAIDs can help treat the following types of pain2, 3, 4:

  • headaches and migraines
  • toothache
  • period pains
  • pain from sprains
  • fever from colds and flu
  • general aches and pains
  • pain associated with inflammation, for example in conditions such as rheumatoid arthritis and osteoarthritis (NSAIDs, in particular, are suited here)

How do OTC Painkillers Work?

In addition to relieving pain, NSAIDs also have an anti-inflammatory effect. They work by stopping the production of certain chemicals that cause inflammation and pain.

It is unclear exactly how paracetamol relieves pain1. However, researchers traditionally believe that it inhibits certain pathways in the central nervous system, similarly to NSAIDs6.

Another key difference between NSAIDs and paracetamol is that the latter does not reduce inflammation6.

Finally, some experts also believe that paracetamol relieves pain by activating the brain’s natural pain-relieving system, called the endocannabinoid system6.

Fun fact, the endocannabinoid system is also responsible for the incredible variety of psychological effects caused by consuming tetrahydrocannabinol, which is the psychoactive compound present in cannabis. Amazingly, the endocannabinoid system is actually a very recent discovery. It is responsible for regulating immune function, blood sugar, and hormones, to name just a few of its functions.16

Side effects of OTC Painkillers

Paracetamol and NSAIDs are generally safe when taken correctly. However, side effects can sometimes occur.

Paracetamol side effects are rare1,3. They include:

  • rashes, swelling, or allergic reactions
  • blood disorders, such as anemia (low number of red cells), leukopenia or neutropenia (low number of white blood cells)
  • liver damage (4g max daily dose must be respected to avoid this)
  • some metabolic and electrolyte disorders, such as high blood sugar, or low calcium levels

NSAIDs such as ibuprofen and aspirin may cause side effects. However, not everyone gets them.

For ibuprofen, common side effects include4:

  • nausea or vomiting
  • constipation or diarrhea
  • indigestion (dyspepsia) or abdominal pain

For aspirin, common side effects include2:

  • indigestion and stomach aches
  • bleeding or bruising more easily

All NSAIDs may cause: 

  • gastrointestinal side effects, such as nausea, anorexia, indigestion, abdominal pain, ulcers, stomach bleeding, perforation, constipation, diarrhea
  • kidney related side effects, such as salt and water retention
  • cardiovascular side effects, including hypertension, bruising and bleeding more easily

Antispasmodics: What are They?

Antispasmosmodics are drugs that help stop muscle spasms, contractions, or cramps7. There are two main classes of antispasmodics8:

  • antimuscarinics (a subtype of “anticholinergics”)
  • smooth muscle relaxants

Antimuscarinics

Muscle spasms and contractions happen because neurotransmitters attach to muscarinic receptors in the muscles, causing them to contract.

Antimuscarinics block certain chemicals such as acetylcholine from attaching to these muscarinic receptors9. By blocking these chemical from attaching to the receptors, antimuscarinics stop nerve impulses from reaching smooth muscle cells thereby reventing painful spasms7.

Common antimuscarinics include8:

  • Hyoscine N-butylbromide main ingredient in Buscopan®
  • Atropine sulfate
  • Dicycloverine hydrochloride

Smooth Muscle Relaxants

Smooth muscle relaxants act directly on the muscles, through various other mechanisms that do not involve blocking neurotransmitters11. Smooth muscle relaxants do not have anticholinergic effects. This class of medications includes:

  • Peppermint oil
  • Drotaverine hydrochloride
  • Mebeverine hydrochloride

Antispasmodics: What do they do?

Hyoscine N-butylbromide (Buscopan®) and Other Antimuscarinics

Generally, antimuscarinics are used to treat8,9:

  • gastrointestinal muscle spasm
  • bladder spasm9

Hyoscine N-butylbromide (Buscopan®), in particular, decreases the movement of the gut (gastrointestinal motility) and acts on receptors in the stomach’s smooth muscle9. For these reasons, it is used for treating various types of abdominal pain, such as12:

  • gastrointestinal spasms
  • spasm of the genito-urinary tract

To find out more about the different types of abdominal pain, read our article, Understanding Abdominal Pain and What it Means for Your Health

Learn more: “What Does the Location of my Abdominal Pain Mean?”

How Do Antispasmodics Work?

Hyoscine N-butylbromide (Buscopan®)

A benefit of Hyoscine N-butylbromide (Buscopan®) is that it acts locally. By acting locally on the gut wall, it relaxes the smooth muscles of the belly, reducing painful contractions.

Hyoscine N-butylbromide (Buscopan®) does not cross the blood-brain barrier, a permeable membrane that can let some molecules pass through the brain. Hyoscine N-butylbromide (Buscopan®) is effective at a local level because it binds to the receptors really well, and it is retained in the tissues of the gastrointestinal tract, kidneys12. This makes Hyoscine N-butylbromide (Buscopan®) efficient and tough on pain, while remaining gentle on the stomach12. It also means it won’t affect you in other areas of your body, or other ways, such as impairing your ability to drive.

Hyoscine N-butylbromide (Buscopan®) is part of a class of antimuscarinics that are generally better tolerated than other antimuscarinics8. This is because they are less likely to cross the blood-brain barrier and are therefore unable to reach the central nervous system8, where they could cause unwanted side-effects.

Most people who take Hyoscine N-butylbromide (Buscopan®) experience no side effects. In very rare instances people may experience minor side effects, such as14:

  • dry mouth
  • constipation
  • blurred vision
  • increased heart rate

Antispasmodics vs. OTC Painkillers

Unlike some painkillers, which cut the pain signals in the brain and do not solve the pain itself, antispasmodics like Hyoscine N-butylbromide (Buscopan®) relieve cramps and abdominal pain at the source. That is to say, OTC painkillers work all over the body, as opposed to focusing on the site and cause of pain, like Buscopan®.

Furthermore, antispasmodics such as Hyoscine N-butylbromide (Buscopan®) are tough on abdominal pain, but at the same time are well tolerated and gentle on the tummy, unlike a painkiller such as ibuprofen.

In general, antispasmodics have a well-established safety profile10. Evidence also suggests that in some forms of abdominal pain, antispasmodics have an edge over analgesics. For example, one study of women living with abdominal pain, cramps, and discomfort found that hyoscine butylbromide was perceived as being more effective than painkillers, and even helped people return to their daily activities more quickly17.

Another study compared hyoscine butylbromide with aspirin for the treatment of period cramps and found that both compounds were effective18. However, the study suggested hyoscine butylbromide may be a safer treatment option, because aspirin may cause gastrointestinal bleeding.

Don’t let belly pain hold you back.

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