Find information on specialist treatments and new treatments for very rare conditions.
Bile acid sequestrants (resins)
Bile acid sequestrants (BAS) are medications that work by targeting bile acids. They are also known as anion exchange resins or simply resins.
Bile acids are made in the liver from cholesterol and are needed for digestion. They are secreted into the intestine to help break down fats, then most are reabsorbed into the blood and carried back to the liver.
These medicines work by binding to bile acids, stopping them from being reabsorbed into the blood and recycled. This means the liver has to take more cholesterol out of the blood to make more bile acids, lowering LDL cholesterol in the blood.
How well do they work?
They have been shown to lower cholesterol by 18-25% at higher doses. They have no effect on HDL cholesterol (good cholesterol) but may cause a rise in triglyceride levels – your doctor will monitor you for this.
Who can take them?
Since modern treatments such as statins became available, UK national guidelines don’t recommend bile acid sequestrants for treating raised cholesterol, so they should only be prescribed by a specialist.
How do you take them?
- A powder (Colestipol and Colestyramine) which you mix with a liquid. This type can interact with other drugs so you need to take it on its own, without other medicines.
- A tablet (Colesevelam). This has fewer interactions and can be taken alongside other medicines such as statins and ezetimibe.
Both forms should be taken with a meal.
Fibrates are medications known as ‘peroxisome proliferator activated receptor agonists’. The most commonly-used are known as bezafibrate and fenofibrate.
They regulate various steps in lipid (fat) metabolism and their main effect is on reducing triglycerides.
How well do they work?
They have been shown to:
- lower triglycerides by 50%
- lower LDL cholesterol by up to 20% (although this is variable)
- raise HDL cholesterol (‘good cholesterol’) by up to 20%.
Who can take them?
Fibrates should only be prescribed by a lipid specialist. They are used alongside statins to help lower triglyceride levels, so they can be used to treat mixed cholesterol and triglyceride conditions such as Familial Combined Hyperlipidaemia (FCH) and Type 3 hyperlipidaemia.
Lomitapide (Lojuxta) is used to treat the rare form of FH (called HoFH) to lower LDL cholesterol in the blood. It works by blocking a protein (called MTP or Microsomal triglyceride transfer protein) that is needed to transport fat from the gut into the blood.
People taking lomitapide need to follow a very low fat diet to avoid gastric (digestive) side effects.
Volanesorsen (brand name Waylivra) can sometimes be prescribed for people with Familial Chlylomicronaemia Syndrome (FCS).
FCS is a very rare, life threatening condition, thought to affect 1-2 people per million in England. It causes very high triglyceride levels in the blood, acute (sudden onset) pancreatitis, fatigue, a high risk of diabetes and a high risk of chronic (long term) pancreatitis.
The raised triglycerides are due to low levels or lack of the enzyme lipoprotein lipase, which normally clears triglycerides from the blood. Treatment options are limited and medications such as statins and fibrates have little effect. The mainstay of treatment is to follow a very low fat diet with only 10g-20g fat per day, and to avoid alcohol.
Who can have volanesorsen?
Volanesorsen has been recommended in the UK as a treatment option for adults with FCS that’s been confirmed with a genetic test, who are at high risk of pancreatitis, and where diet and other treatments are not working well.
How does it work?
It is known as an “antisense oligonucleotide” which means it is a medication which works at genetic level, inhibiting the production of a specific protein. The protein involved is known as ApoCIII, which raises triglyceride levels because it inhibits enzymes such as lipoprotein lipase. Volanesorsen attaches itself to apoCIII mRNA and prevents this protein from being made. This means triglycerides can be broken down and cleared from the blood more effectively.
How well does it work?
Clinical evidence shows short term benefits with volanesorsen but it’s unclear if this is maintained in the long term. It has been approved for use due to the important clinical and psychological benefits it may give people with FCS.
How do you take volanesorsen?
Volanesorsen is given by injection once a week for three months at a starting dose of 285mg, followed by a maintenance dose once every two weeks. You will have a regular review with a specialist to see how well it’s working.
Icosapent ethyl (brand name Vazkepa) is a highly-purified omega 3 fatty acid (eicosapentaenoic acid or EPA). It’s a new treatment for people with known cardiovascular disease (diseases of the heart and blood vessels) who:
- already have well controlled cholesterol on a statin
- but are still seen as higher risk of heart attacks and strokes due to other factors such as high triglycerides.
NICE have approved it for people with a fasting triglyceride level of 1.7mmol/L or above.
Evidence from the REDUCE IT clinical trial showed that the risk of cardiovascular events (such as heart attacks and strokes) was significantly lower in those who received icosapent ethyl compared with those who received a dummy pill (placebo).
Read more about icosapent ethyl