PTCB Guide to Statins!May 6th, 2022
What are “statins”?
Statins are important medicines to prevent heart disease and stroke. About 28 percent of Americans over the age of 40 take a statin medicine. That figure is likely to rise in the coming years given that obesity levels remain unchecked. Here, in this PTCB guide to statins, we review the must-know facts about this common drug class.
The clinical purpose of statins is to reduce bad cholesterol levels, what is referred to as LDL cholesterol. Indirectly, statins also reduce triglyceride levels – an important indirect effect because high levels of triglycerides, a type of fat, is correlated with an increased risk of cardiovascular disease.
Statins are used to:
- Prevent cardiovascular disease – both in patients at risk of experiencing a cardiovascular event, such as heart attack or stroke, and in patients who have already experienced cardiovascular events and need to prevent any further events.
- Hypercholesterolemia – to lower blood cholesterol levels in patients found to have elevated levels. Statins are typically prescribed when lifestyle factors have proven insufficient on their own. Nonetheless, patients are advised to improve diet and exercise to maximize the blood lowering cholesterol effects.
Statins are easily identifiable with the suffix –statin. As you may have seen on many PTCB practice tests, students are expected to know the common brand names of the most common statins.
These medicine brands include:
Now that we understand what statins are used to treat and what the most common brand names are, next we need to discuss the mechanism of action of statins – how they work to achieve their therapeutic effects.
Mechanism of Action
Statins are classified as HMG-CoA reductase inhibitors.
HMG-CoA is an important enzyme in cholesterol production (HMG-CoA is 3-hydroxy-3-methyl-glutaryl coenzyme A). This enzyme is the rate-limiting enzyme in the mevalonate pathway of cholesterol production. Put simply, once this enzyme is blocked, it decreases cholesterol production by the liver and increases the elimination of cholesterol circulating throughout the blood. LDL levels are lowered, and, through indirect means, harmful triglycerides are reduced too.
Statins have also been found to increase HDL cholesterol, the good kind. This means that statins not only slow the pathological process of clogged arteries but may also reverse this process to some degree.
For the PTCB test, students should know the most common side effects with statins. After all, as pharmacy technicians, you will dispense these medicines to patients on an almost daily basis – perhaps even many multiple times per day.
The most common side effects of statins are:
- Gastrointestinal disturbances
- Increase in liver enzymes
- Increased risk of type 2 diabetes in at-risk patients
- Muscle aches
- Myopathies – or muscle weakness
In rare cases, this muscle damage can lead to the potentially fatal condition known as rhabdomyolysis – where the muscle breaks down to toxic metabolites that can cause severe damage to the kidney and other parts of the body.
Grapefruit Juice and Statins
Food and drug interactions are routinely examined on the PTCB test.
One of the most notable food-drug interactions with statins is the effect of grapefruit juice. Grapefruit juice inhibits liver enzymes – known as CYP enzymes – that otherwise metabolize drugs. By influencing how these enzymes behave, certain foods can increase or decrease the metabolism of certain drugs.
In the case of statins, grapefruit juice inhibits CYP enzymes that otherwise break statins down. As a result, statin levels accumulate in the body and the risk of adverse effects increases – often substantially. However, not all statins interact with grapefruit juice to the same degree. Some statins are unaffected by grapefruit juice, whereas other statins are highly affected by the juice.
|Unaffected Statins||Highly Affected Statins|
Clinical and Drug Interactions
Statin levels in the body increase if they are taken alongside:
- Amiodarone – an antiarrhythmic drug
- Diltiazem – a calcium channel blocker
- Itraconazole – an azole antifungal drug
- Macrolides – antibacterials such as clarithromycin
- Protease inhibitors – drugs used to treat HIV/AIDS
It’s also worth noting that patients are typically counseled to take statins at night. This is because cholesterol production is more active at night and so, by taking the statin in the evening, it combats cholesterol production when it is at its highest rate of production.
That completes our PTCB guide to statins! By committing these facts to memory, you will ace any statin-related questions should they appear on the day of your exam. Check back to our PTCB blog soon for more guides to help you master the science of medicines!