Certain types of cholesterol-reducing drugs may not be recommended for patients with certain conditions. Liver disorders are a particular concern.

Most cholesterol-lowering drugs are not known to cause changes in the ability of patients with diabetes to control glucose (blood sugar). However, researchers have found that nicotinic acid can cause hyperglycemia.

Patients who have or are at risk of diabetic nephropathy or other kidney disease are advised to ask their physician about the possible effects of statins or other cholesterol drugs on their kidney function.

In addition, conditions that may affect use of statins include:

• Alcohol abuse.
• Electrolyte imbalance.
• Deficient metabolism of enzymes.
• Severe infection.
• Low blood pressure (hypotension).
• Organ transplant (e.g., heart transplant, kidney transplant or pancreas transplant).
• Recent major surgery or trauma.

Conditions that may affect use of fibrates include:

• Gastrointestinal ulcer.
• Gallbladder stones or disease.
• Hypothyroidism (underactive thyroid gland).
• Heart transplant.
• Increased levels of homocysteine (a metabolic byproduct that may raise cardiovascular risks).

In addition to diabetes, conditions that may affect use of nicotinic acid include:

• Bleeding problems.
• Glaucoma.
• Gout.
• Low blood pressure.
• Stomach ulcer.

Conditions that may affect bile acid resins include:

• Gallstones.
• Bleeding problems.
• Stomach problems (e.g., heartburn, ulcers).
• Constipation and hemorrhoids.
• Hypothyroidism.
• Phenylketonuria (a disorder that makes it difficult for the body to break down certain types of food). Sugar-free versions of bile acid resins may contain phenylalanine, an ingredient in the artificial sweetener aspartame. Aspartame can cause problems in people with phenylketonuria.