Pravastatin

Pravastatin belongs to the statin family. It reversibly blocks HMG-CoA reductase, the rate-limiting enzyme that converts HMG-CoA into mevalonate, the precursor of cholesterol. By slowing this first step, it reduces the production of cholesterol in the liver. This is a competitive and selective inhibition, common to the entire statin class.

Deprived of part of its internal production, the liver responds by increasing the number of LDL receptors on its surface. These receptors capture the LDL cholesterol circulating in the blood and remove it from the circulation, so that LDL cholesterol and total cholesterol fall. This LDL is precisely the one that infiltrates the artery wall and forms atheroma plaques there. By lowering it, pravastatin slows this deposition.

Pravastatin is prescribed to lower cholesterol and reduce the risk of heart attack and stroke linked to the buildup of cholesterol in the arteries. The plaques that form in the artery wall are the origin of heart attack and stroke, and LDL is the driver of their growth. By removing this LDL from the circulation, the treatment acts directly on this mechanism.

The goal depends on each person’s situation. In some people, it is a matter of preventing a first cardiovascular event; in others, already affected, of avoiding a recurrence. It is the physician who establishes the indication based on the lipid profile and the overall level of risk. The expected benefit is measured over years, which explains why the treatment is designed to last.

Pravastatin is taken orally, once a day. It can be swallowed at any time of day, with or without food: the effect on lipids is similar whether the tablet is taken during the meal or one hour before. Consistency matters more than the timing, because it is the daily dose that keeps the enzyme slowed day after day.

The half-life of pravastatin itself is short, around 1.8 hours, while the half-life of total radioactivity, including metabolites, reaches 77 hours. This action therefore works through a regular intake rather than a single strong dose. The treatment should not be stopped on one’s own initiative: it is the physician who decides whether to maintain, adjust or stop it, based on the results and tolerance.

Muscle pain is the effect most often mentioned with statins. In long-term trials, myalgia was reported in 2.3 percent of patients on pravastatin, versus 1.2 percent on placebo; musculoskeletal pain affected 24.9 percent of patients versus 24.4 percent on placebo. Digestive disorders and headaches remain close to placebo: nausea or vomiting 7.4 percent (7.1 on placebo), diarrhea 6.7 percent (5.6) and headache 6.3 percent (4.6).

Serious muscle damage is rare. Rhabdomyolysis is the most severe complication but it remains exceptional; myopathy depends on the dose and most often resolves on stopping. An elevation of liver transaminases is usually transient. Statin treatment is associated with an increase of about 9 percent in the risk of new-onset diabetes (odds ratio 1.09; 95 percent confidence interval from 1.02 to 1.17).

Diet acts on the same ground as your treatment. Soluble fiber is the best-established example: the beta-glucans in oats and barley capture part of the cholesterol in the intestine and reduce its absorption. They are found in oats, barley, legumes such as lentils and chickpeas, as well as in apples. Oily fish provide omega-3s, olive oil and nuts provide good fats, within a dietary pattern favorable to the heart.

On a statin, the blood concentration of coenzyme Q10 decreases significantly, an effect found with several statins including pravastatin (mean difference of about 0.44 micromoles per liter). The link between this decrease and possible muscle pain remains debated: some studies find that supplementation eases muscle symptoms without changing creatine kinase, others find no benefit. The diet provides little coenzyme Q10, mainly through meats and oily fish, and the body makes most of it itself. When this production is slowed, a targeted intake may be discussed, in addition to your treatment, never in its place.

Certain combinations increase the muscle risk and call for precautions. With ciclosporin, start at 10 mg without exceeding 20 mg per day; with clarithromycin or erythromycin, do not exceed 40 mg per day; the combination with gemfibrozil should be avoided, and the addition of niacin, fibrates or colchicine requires monitoring. An ion-exchange resin, which binds bile acids, must be taken separately: pravastatin is swallowed at least one hour before or four hours after the resin, otherwise its absorption falls. The product is contraindicated in acute liver failure, decompensated cirrhosis, or hypersensitivity to the molecule or the excipients.

Monitoring frames the treatment. A liver panel with measurement of transaminases is recommended before starting, then according to the clinical situation. Cholesterol monitoring relies on a lipid profile at the outset, repeated 4 to 12 weeks after starting or a dose change. The patient should report any unexplained muscle pain, tenderness or weakness, especially if accompanied by malaise or fever.