Related Experiment Video
Updated: May 25, 2026
12:08
Field Identification of Matricaria chamomilla using a Portable qPCR System
Published on: October 10, 2020
Drug interactions with herbal medicines.
1Department of Pharmacy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China.
Clinical Pharmacokinetics
|January 20, 2012
Summary
Herbal medicine-drug interactions pose risks, especially for medications with a narrow therapeutic index. Understanding these interactions, often involving cytochrome P450 enzymes and drug transporters, is crucial for patient safety.
Area of Science:
- Pharmacology
- Pharmacokinetics
- Herbal Medicine
Background:
- Herbal medicine-drug interactions are a growing concern, particularly for patients on narrow therapeutic index drugs.
- These interactions can lead to unpredictable adverse events and reduced treatment efficacy.
Purpose of the Study:
- To summarize known herbal medicine-drug interactions.
- To highlight interactions involving cytochrome P450 enzymes and drug transporters.
- To present potential interactions of common herbal medicines with conventional drugs.
Main Methods:
- Review of in vitro studies, animal studies, case reports, and clinical trials.
- Focus on inhibition or induction of cytochrome P450 enzymes and drug transporters.
- Presentation of interactions for black cohosh, garlic, Ginkgo, goldenseal, kava, milk thistle, Panax ginseng, Panax quinquefolius, saw palmetto, and St John's wort.
Main Results:
- A significant number of herbal medicine-drug interactions have been reported.
- Many interactions are difficult to predict, with some studies yielding contradictory results.
- Interactions involve both pharmacodynamic and pharmacokinetic mechanisms.
Conclusions:
- Clinical implications vary based on co-administered drugs, patient factors, herbal product origin, composition, and dosage.
- Further controlled studies are essential to elucidate interaction mechanisms and optimize herbal medicine use.
- Predicting and managing these interactions requires careful consideration of multiple factors.
Related Concept Videos
01:30Drug toxicity: Drug–Drug Interaction
Drug–drug interactions can precipitate toxicity through multiple mechanisms. Absorption interactions alter how drugs enter the body, exemplified when ranitidine increases the absorption of basic drugs, while cholestyramine decreases the levels of propranolol. Protein binding interactions occur when drugs share the same binding sites on plasma proteins. Drugs like aspirin and warfarin, when bound in excess, can lead to increased free drug concentrations, enhancing the potential for...
01:25Pharmacokinetics: Drug–Drug Interactions
Drug interactions occur when the pharmacological effect of one drug is altered by another substance, either enhancing or diminishing its activity. The drug whose activity is altered is known as the object drug, and the substance causing the alteration is called the agent drug or the precipitant. The net effects of these interactions are mostly undesirable, leading to decreased effectiveness or increased adverse effects. In rare cases, interactions can be beneficial, such as the enhanced...
01:26Pharmacokinetics: Drug–Food and Drug–Viral Interactions
A drug interaction occurs when the concurrent use of another drug, food, or an external substance alters the pharmacological activity of a drug. This interaction can modify the action of the original drug, affecting its effectiveness and safety.Drug–food interactions are significant as they impact drug absorption, metabolism, and excretion. For example, grapefruit juice is a well-known disruptor of drug metabolism. It inhibits the cytochrome P450 3A4 enzyme, crucial for the metabolism of many...
01:24Drug Toxicity: Risk factors
Adverse Drug Reactions (ADRs) are potential complications that arise during pharmacotherapy, influenced by multiple risk factors. Age plays a significant role; both neonates and the elderly are at heightened risk due to their respective immature and diminished metabolic and elimination processes. Gender also impacts ADRs, with females experiencing a 1.5 to 1.7-fold greater risk than males, which may be linked to pharmacokinetic, pharmacodynamic, and hormonal differences. Notably, neonates, the...
01:16Drug toxicity: Idiosyncratic Reactions
Idiosyncratic drug reactions represent abnormal chemical responses that vary significantly among individuals, ranging from extreme sensitivity to low doses to insensitivity to high doses. These reactions often occur due to the drug's covalent binding with serum proteins, forming a foreign hapten that triggers an immunotoxicological response. The variability in drug reactions has a strong pharmacogenetic foundation, with genetic differences crucial in how individuals metabolize drugs. For...
01:27Combined Effects of Drugs: Synergism
Synergism is a useful mechanism where combining two or more drugs is more effective than each constituent used alone. Such combinations are also called supra-additive interactions. The drugs collectively enhance the final therapeutic effect by acting on different targets. Another advantage is that the low dose of each constituent drug is sufficient to achieve the desired effect. This helps reduce the duration of therapy and lower the adverse effects of these drugs.
Such synergistic combinations...
Such synergistic combinations...