Statins Side Effects, Muscle Pain, Neuropathy, Liver Damage
Although the usefulness of statins (cholesterol-lowering drugs) for patients with coronary artery disease or those at risk of developing related conditions has been well established, these drugs are not without side effects.
Ideally, each patient with elevated blood cholesterol levels should be screened and considered on an individual basis before a statin, like any drug, is prescribed. The side effects have to be weighed out against the potentially beneficial effect but in significantly elevated cholesterol levels and moderately elevated cholesterol levels that do no respond to conservative management, statins are essential.
Side Effects of Statins
Statins can lead to mild to severe side-effects. In many instance sthe severity of the side effects do depend upon :
- dose (how many milligrams being taken in a day)
- duration of the intake (for how many months or years)
- concomitant use of some other drugs (for any other ailment)
However, this is not always the case and there are instances where a patient on the smallest dose, using statins for a short period of time and with no other drugs being used simultaneously, reports severe side effects.
Statins are known to cause digestive problems like :
- nausea, vomiting
- bloated feeling
- diarrhea
- constipation
These side effects are common to many drugs and are not always considered as a reason to discontinue statin therapy. However serious side effects leading to liver, muscle and kidney damage may sometimes require discontinuation of the drug.
Muscle Pain and Statins
Myalgia and Myopathy
An important and fairly common side effect with statins is the development of myopathy (any disease of muscle) and generalized muscle pain (myalgia). Many people experience aching in the shoulders, pain in the jaw, or pain in the legs. The side effect can range from a common complaint of simple annoying muscle pain (myalgia) to a rare fatal (life threatening) condition known as rhabdomyolysis.
Rhabdomyolysis
Rhabdomyolysis is presence of muscle symptoms along with elevations of the enzyme creatine phosphokinase (CPK) levels 10 times above the ULN (upper limit normal = the highest level that is within the normal reference range) and brown or cola colored urine. Under the influence of statins, tissue breaks down, and then the body has to eliminate the excess waste products. This leads to an overload on the kidneys and sometimes fatal kidney failure.
The cholesterol lowering drug cerivastatin was removed from the market after being implicated in over 60 deaths due to rhabdomyolysis.
Rhabdomyolysis however, remains a rare and dangerous side effect of statins in general. The use of high doses of statins or the concomitant use of drugs like niacin, fenofibrate, cyclosporine or antibiotics like clarithromycin and itraconazole can increase the risk of myopathy or rhabdomyolysis.
Liver Damage and Statins
Hepatotoxicity
Occasionally, statins can result in elevated levels of the liver enzyme alanine aminotransferase (ALT). Normal therapeutic doses of statins may only cause elevated ALT levels in a minority of cases. Other symptoms like malaise (excessive tiredness) and anorexia (decreased appetite) may be noticed or the patient may be asymptomatic.
The elevation in liver enzymes generally occurs in the first 3 months. No discontinuation or modification of dose is recommended if the increase in enzyme levels is not more than 3 times the upper limit of normal value (ULN). If the levels are more than 3 to 4 times of ULN, then the statin may have to be discontinued but only if advised by a doctor.
This increase in the liver enzyme levels is reversible as these reach within the normal range after discontinuation of drug intake. Rarely, the increased levels of liver enzymes can proceed to liver failure. Alcoholics are at an increased risk of having impairment of liver function.
The risk of impairment of liver functions is higher if :
- very high doses of statins are used (example 80 mg/day of simvastatin)
- another cholesterol lowering drug is used simultaneously (e.g. gemfibrozil or niacin etc.)
- the patient has some underlying liver disease
Careful monitoring can prevent the occurrence of such side effects.
Other Sides Effects of Statins
The use of statins may lead to :
- nasopharyngitis (inflammation of the nasal passage and upper respiratory tract)
- headache
- sleep disturbances
- sexual dysfunction
- skin rash and flushing
The latter side effects are more common when using a statin along with niacin.
Nerve Pain and Brain Function with Statins
Peripheral neuropathy (tingling, numbness and burning pain of the limbs) has also been reported by some patients but currently sufficient reports are not available to establish a link with statins.
Previously it was also thought that the use of statins may lead to memory loss, but now it has been established that statins may improve cognition (memory). In additions, statins do not increase the chance of development of diseases like amylotropic lateral sclerosis (ALS) and Alzheimer’s disease, as was once thought.
Monitoring for Statin Side Effects
Regular monitoring can help decrease the incidence of liver, muscle and kidney damage. Physicians generally recommend the measurement of aminotransferase and CPK levels. These levels are assessed at 3 months, then every 6-12 months and whenever the dose of the drug is increased (e.g. shift from 10 mg /day to 20 mg/day). The evaluation of the status of liver, kidney and thyroid before the start of treatment also decreases the incidence of these side effects of statins.
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