General Information About Welchol (Colesevelam)

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Welchol (colesevelam) is a cholesterol-lowering medication that belongs to the bile acid resin class of drugs. Studies have shown that Welchol mainly lowers LDL cholesterol by about 20% and slightly raises HDL by up to 11%. Welchol does not appear to affect triglycerides and, in some cases, may actually raise triglycerides if taken for a prolonged amount of time.

Welchol is also indicated for people with type 2 diabetes to help them control their blood glucose levels and in boys and postmenarchal girls down to 10 years of age diagnosed with heterozygous familial help with lowering their LDL cholesterol.

Although this medication has shown to be effective in lowering LDL, it has not been shown in studies to directly lower the incidence of cardiovascular disease.

Welchol is available in two forms: a powdered form and a tablet. The drug was approved for use in the US by the FDA in May of 2000.

How Does Welchol Work?

Welchol works by binding to bile acids in the small intestine and preventing their reabsorption. Bile acids are derived from cholesterol and help with the digestion of fats consumed through your diet. Bile acids become depleted due to being bound to Welchol and are not reabsorbed. Because of this, cholesterol will be removed from the blood and converted into bile acids in the liver. This activity removes cholesterol from the blood - causing your LDL cholesterol levels to decrease.

How Should You Take Welchol?

You should take Welchol as directed by your healthcare provider. This will depend on which form you are taking of Welchol.

For the powdered form of Welchol, the recommended dose is one 3.75-gram packet daily, or two, 1.875 gram packets taken twice a day. You should empty the contents of the packet into one-half or one cup of water, diet soda, or fruit juice and mix well. The entire contents of the drink should be consumed, in conjunction with a meal.

For tablets, the recommended dose is to take 6 tablets at one time daily, or divided as three tablets twice a day. Tablets should be taken with meals and a full glass of liquid.

Who Shouldn’t Take Welchol?

Due to its components, there are some instances where Welchol should not be taken. These would include:

  • Individuals who have had a previous allergic reaction to Welchol or any of its components.
  • Anyone who has ever had a bowel obstruction.
  • Individuals who have extremely high triglycerides (greater than or equal to 500 mg/dL), since Welchol could increase your triglyceride levels further. Additionally, if you have been previously diagnosed as having pancreatitis due to high triglycerides, you should not take Welchol.

What Conditions Will Need to Be Monitored While Taking Welchol?

There are some conditions that may need to be watched more closely while you are taking Welchol. If you have any of the following conditions below, your healthcare provider may decide to start you on Welchol, but will need to monitor you to determine whether or not taking Welchol will be potentially harmful to you.

These medical conditions include:

  • Having difficulty swallowing. Welchol tablets are fairly large and may be difficult to swallow if you are already having issues.
  • High triglyceride levels. Having slightly high triglyceride levels will not bar you from taking Welchol, but your healthcare provider may want to monitor your lipids more closely since Welchol can increase your triglyceride levels.
  • Issues with motility of your gastrointestinal tract. Welchol can cause constipation, so this may worsen some of these conditions.
  • Welchol is classified as Pregnancy Category B. Although there have not been extensive studies examining the effectiveness and safety of Welchol in pregnant women, animal studies have not shown harm to the fetus. Since this drug can decrease the absorption of some vitamins, some components of prenatal vitamins may not be effective while taking Welchol. Your healthcare provider will make the decision whether or not you should take this drug.

What Side Effects Should I Expect While Taking Welchol?

Gastrointestinal side effects are the most common side effects experienced when using Welchol. These include:

  • Bloating
  • Heartburn
  • Nausea
  • Indigestion
  • Constipation
  • Abdominal pain

Other side effects, such as muscle pain and sore throat, have also been reported in studies. If these side effects become bothersome, you should let your healthcare provider know. He or she may give you something to treat the side effect, adjust your dose, or switch you to another cholesterol-lowering medication.  

Which Medications Can Interact with Welchol?

The following drugs may interact with Welchol by decreasing the amount of the medication absorbed into your blood. As a rule, it is probably a good idea not to take any other medications or supplements four hours before or six hours after taking any bile acid resin drug, such as Welchol. If you are required to take one of the drugs or supplements listed below, your healthcare provider may need to adjust your dose or the time you take it, monitor you more closely for side effects, or discontinue your use of it all together:

  • Thyroid hormones
  • Lanoxin (digoxin)
  • Birth control pills
  • Verapamil
  • Metoprolol
  • Coumadin (warfarin)
  • Fat soluble vitamins (vitamins A, D, E, and K)
  • Medication for seizures, such as Dilantin (phenytoin) and phenobarbital

This is not a complete list, so you should make sure that you disclose all prescribed and over-the-counter medications, and natural products that you are taking. This will help your healthcare provider to identify any potential interactions between Welchol and your other medications. 

Bottom Line

Welchol is a medication that is mostly used to lower your LDL cholesterol but has not been shown to reduce cardiovascular disease in studies. Additionally, because the powdered form of Welchol may intolerable to your palate and the tablets may be hard to swallow, you should let your healthcare provider know if you are experiencing any problems with taking Welchol. Because Welchol only impacts certain parts of your lipid profile, your healthcare provider may want to add additional lipid-lowering therapies – such as a statin or fibrate.


Dipiro JT, Talbert RL. Pharmacotherapy: A Pathophysiological Approach, 6th ed 2005.

Lacy CF, Armstrong LL, Goldman MP, et al. Lexicomp's Drug Information Handbook, 15th ed 2007.

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