Cholestyramine resin is a medication primarily used to lower cholesterol levels in the blood. It belongs to a class of drugs known as bile acid sequestrants. Cholestyramine works by binding to bile acids in the intestines, preventing them from being reabsorbed into the bloodstream. This leads to increased excretion of bile acids in the feces, which prompts the liver to use more cholesterol to produce bile acids, thereby reducing cholesterol levels in the blood.

By preventing the bile acid-bound low-density lipoprotein complex from being absorbed, cholestyramine, an insoluble bile acid binding resin, causes its excretion. These conditions are treated with it:

• be used in conjunction with statins to treat primary hypercholesterolemia and slow the progression of arteriolosclerosis.
• for the treatment of cholestasis-related pruritus brought on by a partial biliary blockage.

Off-Label Uses of cholestyramine in Adults include:

• • Chronic diarrhoea resulting from the malabsorption of bile acids.
  • To enhance the elimination of digoxin (in non-life threatening toxicity)
  • As adjunctive therapy in Graves disease.

Cholestyramine resin Dose in Adults

Cholestyramine resin in dyslipidemia (in patients not achieving the target lipids with the maximally tolerated dose of statins and ezetimibe):

• The usual starting dose of cholestyramine resin is 4 grams, taken 1 to 2 times a day.
• Your doctor may gradually increase this dose every month if needed.
• The typical maintenance dose is between 8 to 16 grams per day, split into two doses.
• The highest dose you should take in a day is 24 grams.

Note: This medication might be suggested for people with moderately high triglyceride levels (up to 300 mg/dL) who haven't reached their cholesterol goals even after trying changes in diet and other cholesterol-lowering medications like statins and ezetimibe.

Cholestyramine resin off-label use in the treatment of chronic diarrhoea due to bile acid malabsorption:  

• The usual starting dose of cholestyramine resin is 4 grams taken once a day.
• Then, your doctor may increase the dose by 4 grams each week, splitting it into 1 to 4 doses per day if needed.
• The highest dose you should take in a day is 36 grams.

It's worth noting that more research might be needed to fully understand how effective cholestyramine resin is for treating this condition.

Cholestyramine resin off-label use in the adjunctive therapy of Hyperthyroidism due to Graves disease:

• The usual dose is 4 grams taken twice a day according to one study (Tsai, 2005), or 4 grams taken three times a day according to another study (Mercado, 1996).

It's important to note that cholestyramine resin is used alongside other medications like antithyroid drugs (such as methimazole or propylthiouracil) and propranolol. These medications work together to manage the symptoms of hyperthyroidism.

Cholestyramine resin dose in Pruritus associated with cholestasis:  

• The typical starting dose of cholestyramine resin is 4 grams taken once or twice a day.
• Your doctor may gradually increase this dose up to 16 grams per day, split into two doses, if needed.

This medication helps by binding to bile acids, which can reduce itching associated with cholestasis.

Cholestyramine resin Dose in Children

Cholestyramine resin does in Diaper dermatitis:

Infants and Children: Topical:

• Cholestyramine resin isn't available as a commercial product for this purpose, so it needs to be specially made by a pharmacist.
• It's usually mixed into ointments or pastes, commonly using bases like Aquaphor® or polyethylene glycol.
• The typical concentration is between 5% to 10%, but it can be compounded at higher concentrations, up to 20%.
• Some pharmacies might use petrolatum as the base for compounding.

Cholestyramine resin Dose in Dyslipidemia:

For children aged 6 years and older with dyslipidemia (high cholesterol), the dose of cholestyramine resin can vary based on age or weight:

• Age-Directed Dosage:
  • Start with 2 to 4 grams per day for the first week, then increase gradually up to 8 grams per day, as tolerated.
  • Children under 10 years old may only tolerate a daily dose of 4 grams.
  • It's better to take the dose once daily with the evening meal for better lipid-lowering effects. If once-daily dosing isn't tolerated, the total daily dose can be split into two doses and taken with morning and evening meals. It can also be taken in three divided doses daily.
  • Doses higher than 8 grams per day may not significantly lower cholesterol further but could increase side effects.
• Weight-Directed Dosage:
  • For children and adolescents, the starting dose is 240 milligrams per kilogram per day, divided into three doses.
  • The dose should be adjusted based on the individual's response, but the maximum daily dose should not exceed 8 grams.

Cholestyramine resin dose in Pruritus secondary to cholestasis:

Children ≤10 years old:

• Start with 240 milligrams per kilogram per day, divided into 2 or 3 doses.
• Give the doses in the morning around breakfast and, if needed, a third dose at lunch.
• The dose can be adjusted based on how effective it is. Some experts suggest a maximum daily dose of 4 grams, but higher doses up to 6.6 grams have been used in children under 10. Higher doses may cause increased fat in the stool (steatorrhea), which might require reducing the dose.

Children >10 years old and Adolescents:

• Start with 240 milligrams per kilogram per day, given in the morning before breakfast.
• The dose can be adjusted based on how effective it is. Some experts suggest a maximum daily dose of 8 grams. However, adult guidelines recommend starting with 4 grams per day and increasing up to 16 grams per day if needed. Higher doses may also lead to increased fat in the stool, requiring a dose reduction.

Cholestyramine resin Diarrhoea secondary to intestinal failure and short-bowel syndrome:

Children and Adolescents:

• Oral: Start with 240 milligrams per kilogram per day, divided into three doses.
• The maximum daily dose suggested is 8 grams per day, but it's important to note that there haven't been completed trials in pediatric patients for this specific use.
• Some experts recommend avoiding the use of cholestyramine resin for this purpose at this time due to limited data.

Pregnancy Risk Factor C

• During pregnancy, it's normal for lipid levels to rise to support the baby's growth, but if they rise too much, doctors usually start with dietary changes.
• If more help is needed, they might suggest bile acid sequestrants like cholestyramine.
• Even though cholestyramine doesn't get absorbed into the body, it might affect how the body absorbs vitamins, so regular prenatal vitamins might not be enough.

Cholestyramine resin use during breastfeeding:

• Since cholestyramine isn't absorbed into the body, it's not likely to pass into breast milk.
• If a breastfeeding woman needs treatment for high cholesterol, bile acid sequestrants like cholestyramine can be an option, according to some sources.
• However, because it might affect how the body absorbs vitamins, it's essential to be cautious if considering it while breastfeeding, as per the manufacturer's recommendation.

Cholestyramine resin Dose in Renal disease:

• The manufacturer's instructions don't specify dosage adjustments for people with kidney problems, but it's important to be cautious if you have renal impairment.
• Cholestyramine could potentially lead to hyperchloremic acidosis, a condition where there's too much chloride in the blood.

Cholestyramine resin Dose in liver Disease:

• Dosage adjustments aren't typically needed for people with liver problems since cholestyramine isn't absorbed from the digestive system.

Cholestyramine resin Side effects:

• Cardiovascular:
  • Edema
  • Syncope
• Dermatologic:
  • Skin rash
  • Urticaria
  • Perianal skin irritation
  • Skin irritation
• Central nervous system:
  • Fatigue
  • Neuralgia
  • Paresthesia
  • Vertigo
  • Headache
  • Anxiety
  • Dizziness
  • Drowsiness
• Gastrointestinal:
  • Biliary colic
  • Constipation
  • Anorexia
  • Dental caries
  • Dental discolouration
  • Dental bleeding
  • Abdominal pain
  • Diarrhoea
  • Diverticulitis
  • Duodenal ulcer with haemorrhage
  • Dysgeusia
  • Flatulence
  • Gallbladder calcification
  • Dysphagia
  • Eructation
  • Gastric ulcer
  • Hiccups
  • Nausea
  • Pancreatitis
  • Rectal pain
  • Melena
  • Tongue irritation
  • Dental erosion
  • Vomiting
  • Gastrointestinal haemorrhage
  • Hemorrhoidal bleeding
  • Steatorrhea
  • Intestinal obstruction
• Endocrine & metabolic:
  • Weight gain
  • Weight loss
  • Hyperchloremic metabolic acidosis
  • Increased libido
• Respiratory:
  • Asthma
  • Dyspnea
  • Wheezing
• Genitourinary:
  • Diuresis
  • Dysuria
  • Hematuria
• Hepatic:
  • Abnormal hepatic function tests
• Neuromuscular & skeletal:
  • Back pain
  • Myalgia
  • Arthralgia
  • Arthritis
  • Osteoporosis
• Hematologic & oncologic:
  • Hemorrhage
  • Hypoprothrombinemia
  • Prolonged prothrombin time
  • Adenopathy
  • Anemia
  • Bruise
  • Rectal hemorrhage
• Ophthalmic:
  • Nocturnal amblyopia
  • Uveitis
• Otic:
  • Tinnitus

Contraindications to cholestyramine resin include:

• Cholestyramine shouldn't be used if someone has a hypersensitivity (allergic reaction) to bile acid sequestering resins or any part of the medication's formula.

Warnings & Precautions

Bleeding:

• Long-term use of cholestyramine, especially in high doses, might lead to bleeding issues.
• To help prevent this, doctors may recommend oral vitamin K therapy alongside cholestyramine treatment.
• Vitamin K plays a crucial role in blood clotting, so supplementing it can counteract the potential bleeding problems associated with cholestyramine use.

Constipation:

• Cholestyramine can cause constipation or make existing constipation worse.
• If a person has a history of constipation, doctors might start them on a lower dose to minimize this side effect.
• It's important to be aware that cholestyramine could worsen hemorrhoids, which are swollen veins in the rectum or anus.

Hypertriglyceridemia:

• Bile acid sequestrants like cholestyramine shouldn't be used in patients with high baseline fasting triglyceride levels of 300 mg/dL or higher or in those with type III hyperlipoproteinemia, as they can lead to severe elevations in triglyceride levels.
• If a patient's triglyceride levels are between 250 to 299 mg/dL, caution is advised when using bile acid sequestrants, and a follow-up lipid panel should be done within 4 to 6 weeks after starting treatment.
• If triglyceride levels exceed 400 mg/dL, the use of bile acid sequestrants should be discontinued.

Renal impairment:

• It's important to be cautious when using cholestyramine in patients with renal impairment, which means their kidneys aren't functioning as well as they should.

Cholestyramine resin: Drug Interaction

Note: Drug Interaction Categories:

• Risk Factor C: Monitor When Using Combination
• Risk Factor D: Consider Treatment Modification
• Risk Factor X: Avoid Concomitant Use

Monitoring Parameters:

Before Treatment:

• Get a lipid profile test, whether fasting or nonfasting, before starting treatment for high cholesterol.

During Treatment:

• Check a fasting lipid profile 4 to 12 weeks after starting therapy.
• After that, continue to monitor with lipid profile tests every 3 to 12 months.

How to administer cholestyramine resin?

Prepared Suspension:

• Administer the prepared suspension orally.
• Do not take cholestyramine in its dry form.
• Avoid sipping or holding the suspension in the mouth for too long, as it may cause tooth discoloration or enamel decay.

Timing of Administration:

• It's recommended to take cholestyramine at mealtime.
• While twice-daily dosing is suggested, it can be taken in 1 to 6 doses throughout the day.

Mechanism of action of cholestyramine resin:

• Cholestyramine works by creating a nonabsorbable mix with bile acids in the gut, releasing chloride ions in the process.
• This action stops the reabsorption of bile salts in the intestine, which leads to more bile salt-bound low-density lipoprotein cholesterol being excreted in the feces.

Onset and Peak Effect:

• Onset of Action: Cholestyramine's effects typically start to show over time.
• Peak Effect: The maximum impact is usually reached around 21 days after starting treatment.

Absorption and Excretion:

• Absorption: Cholestyramine isn't absorbed by the body.
• Excretion: It's eliminated primarily through the feces, forming insoluble complexes with bile acids.

Cholestyramine International Brand Names:

• Cholestyramine-ODAN
• Questran
• Questran Light
• Questran Lite
• DOM-Cholestyramine
• NOVO-Cholamine
• Novo-Cholestyramine Light
• Olestyr
• Olestyr Light
• Choles
• Cholestran
• Colestiramina
• Olipo
• Lipramina
• Zuckerfrei
• Quantanash
• Quantalan
• Quantalan
• Colestrol
• Efensol
• Kolestran
• Questran Loc
• Resincolestiramina
• Semide
• Sequest
• Vasosan P-Granulat
• Vasosan S-Granulat

Cholestyramine brands in Pakistan:

Questran sachet (4.0 gms per sachet) - Bristol-Myers Squibb