Bentyl vs Linzess

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For patients with irritable bowel syndrome (IBS) or chronic idiopathic constipation, certain drugs that alter the functioning of the digestive system can help in managing symptoms and discomfort. Bentyl and Linzess are two such medications that are often prescribed for these conditions. They each have different effects on the gut but both aim to provide relief from abdominal pain and irregular bowel movements associated with these disorders.

Bentyl is an anticholinergic medication, blocking a neurotransmitter called acetylcholine in its receptors located primarily in smooth muscles of the gut and bladder; it helps by reducing spasms in the stomach muscles which relieves cramping.

On the other hand, Linzess increases fluid secretion into your intestines which can help you pass stool more easily. This drug falls under a class known as guanylate cyclase-C agonists, promoting increased movement within the intestine and reducing pain related to IBS.

What is Bentyl?

Dicyclomine (the generic name for Bentyl) and Linzess are two medications commonly used to manage symptoms of irritable bowel syndrome (IBS). Dicyclomine, an antispasmodic, was first approved by the FDA in 1950. It works by blocking acetylcholine receptors in the smooth muscle of the gut, reducing spasms and associated pain. Bentyl is typically prescribed for IBS with a predominant symptom of abdominal pain or cramping.

Linaclotide (the active ingredient in Linzess), on the other hand, was approved by the FDA more recently in 2012. It functions differently than dicyclomine; it increases fluid secretion into your intestines which can help ease constipation. This makes it especially effective for those with IBS-C or chronic idiopathic constipation where constipation is a primary symptom.

While both drugs aim to alleviate discomfort related to IBS, their method of action differs significantly along with their side effect profiles. Drowsiness and dry mouth are common side effects seen with Bentyl due to its anticholinergic properties while diarrhea is most commonly reported with Linzess.

What conditions is Bentyl approved to treat?

Bentyl is approved for the treatment of functional bowel/irritable bowel syndrome (IBS), while Linzess is used to treat multiple gastrointestinal disorders:

  • Irritable Bowel Syndrome with Constipation (IBS-C)
  • Chronic idiopathic constipation (CIC)
  • Opioid-induced constipation in adults with chronic non-cancer pain.

How does Bentyl help with these illnesses?

Bentyl works to manage irritable bowel syndrome (IBS) by blocking the action of acetylcholine, a neurotransmitter that is involved in muscle contractions in the gut. By doing this, Bentyl reduces spasms and cramping, common symptoms of IBS. Acetylcholine plays a crucial role in initiating muscular contractions necessary for digestion, amongst other things. In individuals with IBS, it is thought that there may be an overproduction or increased sensitivity to acetylcholine which leads to excessive muscle contractions and resultant pain or discomfort. Therefore, by reducing these effects through the blockade of acetylcholine receptors on smooth muscles lining the gastrointestinal tract, Bentyl can limit the negative effects associated with IBS and aid patients in managing their condition.

On the other hand, Linzess manages constipation-predominant IBS differently by increasing levels of cyclic guanosine monophosphate (cGMP), leading to accelerated intestinal transit time due to enhanced secretion of chloride and bicarbonate into the intestinal lumen resulting in increased fluid allowing stools pass more smoothly through your bowels. The end effect helps ease constipation related issues often experienced with certain types of IBS.

What is Linzess?

Linzess, the brand name for linaclotide, is a guanylate cyclase-C agonist that increases the concentrations of cyclic guanosine monophosphate (cGMP). An increased cGMP concentration leads to accelerated chloride and bicarbonate secretion into the intestinal lumen which increases intestinal fluid and accelerates transit. It was first approved by the FDA in 2012.

As Linzess does not inhibit acetylcholine like Bentyl (an anticholinergic), its side effect profile differs notably from that of Bentyl. Specifically, it does not cause dry mouth or blurry vision—common side effects associated with Bentyl usage. The actions on increasing cGMP can be beneficial for treating constipation-related disorders such as irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC), especially in patients who don't respond well to typical antispasmodics like Bentyl.

What conditions is Linzess approved to treat?

Linzess is FDA-approved to treat certain conditions related to the digestive system including:

  • Chronic idiopathic constipation (CIC)
  • Irritable bowel syndrome with constipation (IBS-C) in adults. These disorders can cause symptoms such as stomach pain, bloating, and difficulty having a bowel movement. Linzess works by helping your bowels move more frequently and relieving associated discomfort.

How does Linzess help with these illnesses?

Guanylate cyclase-C is an enzyme found in the lining of the intestines and plays a crucial role in regulating fluid levels within, aiding in bowel movements and thus playing a significant part in our digestive health. Low activity or dysfunction can lead to constipation. Linzess works by increasing the activity of this enzyme, thereby promoting smoother bowel movement and alleviating some symptoms of irritable bowel syndrome with constipation (IBS-C) or chronic idiopathic constipation (CIC). Its action on intestinal contraction and fluid secretion may also play roles in its effectiveness as a treatment for these conditions. Since it does not have significant antispasmodic effects like Bentyl does, it's often prescribed when patients primarily suffer from constipation rather than abdominal pain or spasms related to IBS-D (irritable bowel syndrome with diarrhea), or may be combined with antispasmodics if needed.

How effective are both Bentyl and Linzess?

Both dicyclomine (Bentyl) and linaclotide (Linzess) have proven efficacy in treating patients with Irritable Bowel Syndrome (IBS), although they were approved by the FDA several decades apart. As they act on different parts of the gastrointestinal system, they might be prescribed under variant circumstances. The effectiveness of Bentyl and Linzess in alleviating IBS was studied separately; both drugs showed similar efficacy in managing symptoms of IBS along with comparable safety profiles.

A 2007 review indicated that dicyclomine is effective at relieving abdominal pain associated with IBS from the first week of treatment, demonstrating a favorable side effect profile compared to many other antispasmodics, and is well-tolerated even among elderly populations. It has become one of the most widely prescribed drugs for IBS worldwide due to its long history as an antispasmodic medication developed in mid-20th century, which provides significant research into its effectiveness.

On the other hand, a 2012 meta-analysis suggested that linaclotide appears more effective than placebo at reducing symptoms related to constipation-predominant IBS. Despite being considered a newer drug option since it's only been available since 2012, it still proves promising results when used either alone or co-prescribed alongside another GI motility agent. Moreover, due to its unique mechanism acting on guanylate cyclase-C receptors present throughout the gut lining promoting fluid secretion and transit through intestines - linaclotide may be optimal for those who didn't respond well to traditional antispasmodics or have specific needs like chronic idiopathic constipation.

abstract image of a researcher studying a bottle of drug.

At what dose is Bentyl typically prescribed?

Oral dosages of Bentyl range from 40-160 mg/day, divided into four doses. However, studies suggest 80 mg/day is adequate for most people to manage symptoms of irritable bowel syndrome (IBS). The initial dose recommendation for adults is often 20mg four times a day. On the other hand, Linzess dosage typically starts at 145 mcg once daily and can be increased to a maximum of 290 mcg if needed. It's important to note that Linzess should be taken on an empty stomach, at least half an hour before the first meal of the day. Remember that these are general guidelines and your doctor may adjust these dosages based on individual needs and responses.

At what dose is Linzess typically prescribed?

Linzess treatment is typically initiated at a dosage of 145 mcg/day for chronic idiopathic constipation (CIC) and 290 mcg/day for Irritable Bowel Syndrome with Constipation (IBS-C). This should be taken once daily on an empty stomach, at least 30 minutes before the first meal of the day. For patients older than 65 years or those with mild to moderate hepatic impairment, dose adjustment is not required. However, the initial dose can be lowered to 72 mcg if side effects such as diarrhea occur. If there is no adequate response to treatment after a few weeks with Linzess at its initial dosage, consultation with a healthcare provider would be necessary for further instructions and possible adjustments.

What are the most common side effects for Bentyl?

Common side effects of Bentyl and Linzess can vary, as each medication is prescribed for different conditions.

For Bentyl, which is typically used to treat irritable bowel syndrome (IBS), side effects may include:

  • Dry mouth
  • Dizziness
  • Blurred vision
  • Nausea
  • Sleepiness/drowsiness

On the other hand, Linzess, which treats constipation and IBS with constipation in adults, has common side effects that may involve:

  • Diarrhea
  • Gas
  • Abdominal pain or bloating
  • Heartburn

abstract image of a patient experiencing side effect

Are there any potential serious side effects for Bentyl?

While Bentyl (Dicyclomine) and Linzess (Linaclotide) are both used to treat different aspects of irritable bowel syndrome, they can induce different side effects. In the case of Bentyl, some potential serious side effects might include:

  • Allergic reactions: such as difficulty breathing; swelling of your face, lips, tongue or throat
  • Little or no urination
  • Confusion, hallucinations
  • Unusual excitement or restlessness
  • Eye pain and seeing halos around lights
  • Rapid heart rate that's pounding or fluttering in your chest
  • Nervous system disorders causing stiffness in muscles along with high fever

On the other hand, for Linzess severe but rare side effects could encompass:

  • Severe diarrhea leading to dehydration symptoms like dizziness, feeling very thirsty or hot and unable to urinate; Severe stomach pain which could be a symptom of intestinal blockage.

Regardless of whether you're taking Bentyl or Linzess - if you experience any above mentioned serious side effects please contact healthcare provider immediately.

What are the most common side effects for Linzess?

Linzess, commonly used for addressing the symptoms of irritable bowel syndrome (IBS) and chronic idiopathic constipation, can cause the following side effects:

  • Diarrhea or loose stools
  • Gas and bloating
  • Abdominal pain or discomfort
  • Nausea, vomiting
  • Heartburn
  • Fatigue or weakness
  • Headache, dizziness Increased urination is not typically reported with Linzess usage. It's important to note that while these side effects might seem intimidating, they are usually manageable and subside as your body gets accustomed to the drug. However, if any of these persist or worsen over time it's advisable to consult with your healthcare provider promptly.

Are there any potential serious side effects for Linzess?

Linzess, while generally well-tolerated, can have some serious side effects in rare cases. Here are some symptoms that may indicate a severe adverse reaction to Linzess:

  • Signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue or throat
  • Severe stomach pain or diarrhea (especially if it is bloody)
  • A lightheaded feeling like you might pass out
  • Unusual changes in mood or behavior
  • Rapid heart rate
  • Rectal bleeding or bright red bowel movements

If any of these symptoms occur when using Linzess, it's essential to seek immediate medical attention.

Contraindications for Bentyl and Linzess?

Both Bentyl and Linzess, as well as other similar medications for gastrointestinal disorders, may exacerbate symptoms in some individuals. If you notice an increase in abdominal pain or discomfort, severe diarrhea or constipation, please seek immediate medical attention.

Neither Bentyl nor Linzess should be taken if you have been taking drugs that slow down the gut's activity (like opioids) without consulting your doctor first. Always inform your physician about any medication you are currently on; these types of medicines require careful monitoring to prevent dangerous interactions with both Bentyl and Linzess.

In particular, it is important to remember that taking high doses of fiber supplements while on Linzess can result in increased side effects like bloating and stomach cramps. Similarly, using anticholinergic drugs alongside Bentyl could heighten the risk of certain side effects such as dry mouth and urinary retention.

How much do Bentyl and Linzess cost?

For the brand name versions of these drugs:

  • The price for 30 capsules of Linzess (145 mcg) averages around $420, which works out to approximately $14/day.
  • The cost for 100 tablets of Bentyl (10 mg) is about $230, working out to roughly $2.3 per day if you take it four times daily.

Therefore, if you are taking four doses a day of Bentyl (i.e., 40 mg), then brand-name Linzess is more expensive on a per-day treatment basis. However, remember that cost should not be your primary consideration when determining which medication suits your needs best.

When considering generic versions:

  • Dicyclomine (generic version of Bentyl) costs significantly less with prices ranging from $0.50 to $1 per day depending on dosage.
  • Linaclotide, the generic form of Linzess isn't available as this time in U.S., so patients needing this medication will have to opt for the brand name at its higher price point.

Popularity of Bentyl and Linzess

Dicyclomine, also known by its brand name Bentyl, was prescribed to approximately 1.2 million people in the US in 2020. Dicyclomine is a type of drug called an anticholinergic and it's used primarily for treating symptoms of irritable bowel syndrome (IBS). It makes up about 13% of all prescriptions for IBS medications and has been moderately steady in prevalence over the past decade.

On the other hand, Linaclotide or Linzess, another medication prescribed for IBS as well as chronic idiopathic constipation (CIC), saw nearly 3 million prescriptions filled in America during 2020. In terms of overall prescriptions for drugs targeting these conditions, Linzess accounts for just under 30%. The prescription rate of Linzess shows an upward trend since its approval by FDA in 2012.


Both Bentyl (dicyclomine) and Linzess (linaclotide) have a well-established history of use in patients with irritable bowel syndrome. Each has been shown in numerous clinical studies to be more effective than placebo treatments. The drugs work differently: Bentyl is an antispasmodic that helps reduce the frequency of muscle contractions in the gut, while Linzess increases fluid secretion into the intestines to help make stools softer and easier to pass.

In some situations, these medications could be used together under careful supervision by a doctor. However, due to their different mechanisms of action and side effect profiles, they're typically prescribed for different symptoms or types of IBS. For example, Bentyl might be a first-line treatment option for those suffering from IBS with constipation (IBS-C), whereas Linzess may be considered as an addition if patients don't respond adequately to other treatments or require relief from chronic constipation.

Both medications are available in generic form which represents significant cost savings especially for patients who must pay out-of-pocket expenses. Starting any new medication can require an adjustment period during which effects may not yet be noticeable right away.

While both drugs exhibit relatively similar side effect profiles — such as dry mouth, dizziness and bloating — individual tolerability can vary widely. Importantly, patients should monitor their body's reactions when starting these treatments; immediate medical attention should be sought if severe stomach pain or diarrhea occurs.