Drug Interactions with Vitamins and Minerals
Drug Interactions With Common Medications and Supplements
The factors contributing to drug interactions are very complex. The more supplements and medications that a patient is taking, the more likely it is for there to be greater drug interactions that may affect the bioavailability of the drugs they are taking. These interactions may increase or decrease the efficacy of the medications and cause adverse effects. The factors contributing to drug interactions include:
- nature of effect on CYP450 and other enzymes
- site where CYP450 and other enzymes are affected
- potency of supplement(s) and medication(s)
- kinetic properties of supplement(s) and medications(s) (i.e. solubility, lipophilicity, bioactivation, etc.)
- dosage of supplement(s) and medication(s)
- co-morbidities of patient
- net effect of metabolism of the supplement(s) and medication(s) together
These supplements may be dangerous to your health as the active ingredients may have additive or antagonistic effects on certain medications that you may be prescribed- altering both of their efficacies and increasing the likelihood of experiencing adverse effects. It is always important to make sure you do not take supplements in excess, and at an appropriate time separately from other medications it may interact with so its absorption and bioavailability are not altered.
Compatibility of Vitamins and Minerals When Supplemented Together
- compatible= consumption of the vitamins and minerals with medication will lead to optimal absorption.
- non-compatible= consumption of the vitamins and minerals with medication will result in minimal or reduced absorption. It is recommended to take these separately.
- neutral= consumption of the vitamins and minerals with medication will not affect absorption.
Drug Interactions with Food
Table of Adverse Effects of Different Food-Drug Interactions
| Class of Drug | Food/Beverage | Adverse Effect(s) |
| Statins | Grapefruit/Grapefruit Juice | Affects drug metabolism leading to increased bioactivation and accumulation. |
| Calcium Channel Blockers | Grapefruit/Grapefruit Juice | Affects drug metabolism leading to increased bioactivation and accumulation. |
| ACE inhibitors | Potassium-rich foods (i.e. bananas, orange juice, baked potato, avocado, milk) | causes elevated potassium levels in blood (hyperkalemia), increases the risk of heart arrhythmias. |
| ARBs (Angiotensin II receptor blockers) | Potassium-rich foods (i.e. bananas, orange juice, baked potato, avocado, milk) | causes elevated potassium levels in blood (hyperkalemia), increases the risk of heart arrhythmias. |
| Potassium-Sparing Diuretics | Potassium-rich foods (i.e. bananas, orange juice, baked potato, avocado, milk) | causes elevated potassium levels in blood (hyperkalemia), increases the risk of heart arrhythmias |
| Erectile Dysfunction Medications | Grapefruit/Grapefruit Juice and Alcohol | Affects drug metabolism leading to increased bioactivation and accumulation. Alcohol has an additive effect on lowering blood pressure with these medications. |
| MAO Inhibitors | Tyramine Rich Foods (i.e. aged cheese, smoked meats, sauerkraut, soy sauce, tap/draft beer) | causes elevated levels of tyramine in the blood causing dizziness, headaches, and spikes in blood pressure. |
The adverse effects listed are highly variable to the form of the herb and its active components. Herbs can be active in these forms:
- aqueous solution
- oils
- dried powder/herb
- fresh herb
- deodorized preparations
- extract
- teas
- pill/capsule
- ointment/cream
Here’s an example of two different types of drug interactions and their relationships during metabolism–>
Helpful Links
MedScape, 2021
Grapefruit and Some Drugs Don’t Mix
July 1, 2021
