(131) Drug interactions

What are drug interactions?

When one drug affects another drug's action in the body.

What is the function of cytochrome P450 (CYP)?

It is a major drug metabolizing enzyme responsible for roughly 80% of oxidative drug metabolism.

Where is cytochrome P450 primarily found in the body?

In the liver, gastrointestinal tract, and kidney.

What percentage of drugs does CYP metabolize?

Around 90% of the drugs that we use today.

What happens when a drug is a CYP450 inhibitor?

It reduces the metabolism of a target drug, leading to a higher concentration in the body.

What can occur if the concentration of a target drug becomes too high?

It can lead to accumulation to toxic levels.

What effect does a drug inducer have on the target drug?

It increases the breakdown of the target drug, decreasing its concentration and effect.

What mnemonic can be used to remember CYP450 inhibitors?

S Faces.com.

What drugs does the mnemonic 'S Faces.com' refer to?

Sodium borate, azole, cadine, ketoconazole, fluconazole, alcohol, chloramphenicol, sulfonamides, cimetidine, metronidazole.

What mnemonic can help you remember enzyme inducers?

BS C*** GPS Induces My Rage.

What does the mnemonic 'BS C*** GPS' stand for in enzyme inducers?

Barbiturates, St. John's wort, carbamazepine, rifampin, alcohol, phenytoin, phenobarbital, sulfinpyrazone.

What is the mnemonic for drugs metabolized by CYP450?

COW Pets.

What does the 'C' in 'COW Pets' stand for?

Cyclosporine, carbamazepine, citalopram.

What does the 'O' in 'COW Pets' represent?

Oral contraceptive pill.

What does the 'W' in 'COW Pets' stand for?

Warfarin.

What does the 'P' in 'COW Pets' refer to?

Phenytoin and protease inhibitors.

What does the 'A' in 'COW Pets' represent?

Acyclovir and estradiol inhibitors.

What does the 'T' in 'COW Pets' stand for?

Theophylline and trolis.

What does the 'S' in 'COW Pets' represent?

Statins and steroids.

What is one potential beneficial effect of a CYP450 inhibitor?

It allows the target drug to have a greater effect.

What is the downside of needing a lower dose due to a CYP450 inhibitor?

It can lead to toxic accumulation of the drug.

What would likely happen if you used a CYP450 inducer with a target drug?

You would need a higher dose to achieve the same effect.

What is the role of drug interactions when taking medications?

To affect the action and metabolism of drugs in the body.

Why is understanding CYP450 important in pharmacology?

It helps predict drug interactions and adjust dosages accordingly.

How does the body typically handle medicines?

The body tries to break them down through metabolism.

Why might a healthcare provider monitor drug levels when using CYP450 inducers or inhibitors?

To prevent drug toxicity or therapeutic failure.

What two types of interactions can occur with drugs and CYP?

Inhibition and induction of drug metabolism.

What should patients be aware of when taking multiple medications?

They need to be aware of possible interactions between the drugs.

How do drug interactions exemplify the principle of balance in pharmacology?

They show the need for careful dosing to avoid toxicity or ineffectiveness.

What are some examples of curative and preventative medications affected by CYP450?

Warfarin (anticoagulant) and oral contraceptives.

What is the significance of the number 80% in drug metabolism?

It represents the percentage of oxidative drug metabolism done by CYP450.

If a medication requires adjustment due to CYP interactions, what could be a potential reason?

Changes in the concentration of the drug from metabolism alterations.