Grapefruit Juice Interactions

On this episode of the podcast, I discuss my approach and strategies to handle grapefruit juice interactions.

Grapefruit juice causes drug interactions by inhibiting the CYP enzyme system. More specifically, it inhibits CYP3A4 which is responsible for the breakdown of many medications.

Quantity is always an important consideration when assessing grapefruit juice interactions. The more that is taken, typically, the more drug concentrations will be affected.

It is important to assess the use of grapefruit juice when your patient has a history of cardiovascular disease, cardiac conditions, pain, mental health disease, or gout as some medications used to treat these diseases can interact with grapefruit juice.

If you are looking for more content on drug food interactions, be sure to check out my book in the links below.

Be sure to check out our free Top 200 study guide – a 31 page PDF that is yours for FREE!

Study Materials For Pharmacists and Students

Useful Books For Any Healthcare Professional

Nursing Professionals

Dietitian Professionals

Folic Acid Pharmacology

folic acid pharmacology

Folic acid is a water-soluble vitamin; compared to fat-soluble vitamins, accumulation is not as much of an issue. It is responsible for the formation of coenzymes, DNA synthesis, erythropoiesis, and certain metabolic processes. Due to the mechanism of folic acid, if there is a deficiency present, anemia can manifest. Although the recommended dietary intake is 0.2 mg, supplementation may be necessary. Some situations where supplementation may be desired are prevention of neural tube defects in pregnancy, patients suffering from alcohol abuse disorder, bariatric surgery patients, and certain types of GI disorders where malabsorption may be present. If a patient is taking certain medications folic acid supplementation may be necessary as well. Notable drugs where a patient may require folic acid include methotrexate and phenytoin. 

The dosages used most often when supplementing folic acid are in the 1-5 mg range, and most of the time it will be 1 mg. Folic acid has a relatively safe adverse drug reaction profile. Some possible adverse drug reactions are flushing, malaise, erythema, skin rash, and hypersensitivity reactions. Although uncommon, the chance for an adverse drug reaction occurring increases as the dose increases. For monitoring folic acid, the normal levels can vary between 2-20 ng/mL, but they can vary based upon the lab. A type of anemia that can manifest with a folic acid deficiency is megaloblastic anemia. When assessing megaloblastic anemia, vitamin B12 levels should also be assessed. 

Folic acid levels can be impacted by phenytoin, methotrexate, trimethoprim and sulfamethoxazole, sulfasalazine, triamterene, and alcohol. When a patient is only taking trimethoprim and sulfamethoxazole for acute treatment of a UTI, folic acid levels aren’t as concerning. Whenever it changes from acute treatment to prophylaxis, folic acid levels should be monitored more closely. Theoretically, folic acid can lower concentrations of phenytoin, and phenobarbital, so closer monitoring may be warranted.  

Show notes provided by Chong Yol G Kim, PharmD Student.

Be sure to check out our free Top 200 study guide – a 31 page PDF that is yours for FREE!

Study Materials For Pharmacists and Students

Useful Books For Any Healthcare Professional

Nursing Professionals

Dietitian Professionals

Vitamin B12 Pharmacology

On this episode, I cover clinical tips and practice pearls surrounding vitamin B12 pharmacology.

Vitamin B12 deficiency plays a critical role in the development of macrocytic anemia.

There are medications that you have to be aware that can deplete vitamin B12. Metformin, colchicine, and PPIs are some common examples.

A lack of intrinsic factor can lead to B12 deficiency. Intrinsic factor is necessary for adequate GI absorption of vitamin B12.

I discuss important drug interactions on the podcast, be sure to check out my latest project which is a 200+ page book on managing drug interactions in primary care.

Be sure to check out our free Top 200 study guide – a 31 page PDF that is yours for FREE!

Study Materials For Pharmacists and Students

Useful Books For Any Healthcare Professional

Nursing Professionals

Dietitian Professionals

Caffeine Pharmacology

Caffeine is a commonly used supplement and is found in many food and beverages. I discuss caffeine pharmacology, adverse effects, and drug interactions.

Caffeine can inhibit CYP1A2 and also be affected by CYP1A2 inhibitors. I discuss some examples in the podcast.

It is critical to inquire about caffeine intake when patients are reporting insomnia.

Caffeine has been associated with increases in pulse and blood pressure. Be sure to ask about caffeine intake when assessing these vital signs.

I discuss important drug interactions on the podcast, be sure to check out my latest project which is a 200+ page book on managing drug interactions in primary care.

Be sure to check out our free Top 200 study guide – a 31 page PDF that is yours for FREE!

Magnesium Pharmacology

Magnesium Pharmacology

On this episode, I discuss magnesium pharmacology and the clinical applications. Magnesium plays numerous important functions in the body and you may see patients take these supplements under the direction of a healthcare professional and sometimes on their own.

It is very important to remember that magnesium can cause GI upset and diarrhea. This is often overlooked in our polypharmacy patient.

Magnesium can accumulate in renal disease. This is important to remember especially in patients who have a tendency to take a lot of supplements without discussing them with a healthcare professional.

PPI’s are a notorious cause of low magnesium. Loop diuretics can increase magnesium excretion and also cause low magnesium levels.

Magnesium can bind up numerous drugs reducing concentrations and leading to treatment failure. A few examples include quinolone antibiotics, tetracycline antibiotics, and levothyroxine.

Be sure to check out our free Top 200 study guide – a 31 page PDF that is yours for FREE!

Iron Supplement Pharmacology

Iron supplements frequently cause GI upset. Monitor patients for nausea, vomiting, and constipation issues.

There are three main salt forms of iron. Ferrous fumurate has the most elemental iron, ferrous sulfate (2nd most), and ferrous gluconate has the least.

Iron can bind up antibiotics and reduce their effectiveness. Two classic examples include the quinolone and tetracycline antibiotics.

Anemia can be caused by numerous concerns, however, iron deficiency is a very common cause.

Ferritin is a lab that we commonly monitor in a patient who may be iron deficient. Iron deficiency can also lead to symptoms of Restless Leg Syndrome.

Be sure to check out our free Top 200 study guide – a 31 page PDF that is yours for FREE!

Potassium Supplement Pharmacology

On this episode I discuss why we may need to use potassium supplements.

I also talk about a medication error situation involving potassium that lead to a death.

It is important to remember other medications that can raise potassium levels.

I also talk about a dosage form of potassium that might make patients ask some questions.

Enjoy the show and I hope you sign up to get our free 31 page PDF!