Safety in Herb-Drug Combinations #1
Sample of Course Materials
Herb-Drug Interaction Overview
Drug interactions are both pharmacodynamic and pharmacokinetic. Pharmacodynamics concern the actions of two or more drugs and pharmacokinetics concern the absorption, distribution, metabolism, and/or excretion of one or more drugs affecting another. Interactions can be additive, synergistic, and antagonistic. Additive interactions are those wherein the effects of two or more chemicals taken together is equal to the sum of taking them separately. Synergistic interactions occur when taking two or more substances together results in a stronger action than the sum of taking them separately. The substances increase each others’ effects. Antagonistic interactions are when taking substances together weakens their overall effect.
Chinese Medicine (CM) uses differential diagnosis in determining the appropriate herbs. Herbal choices are based on the functions of the individual herbs and the overall function of a formula. When patients consume western medications with herbs, care must be taken not to alter the effects of the western medicine such that adverse reactions occur. This can happen when... (more in course materials)
1. Allergy Medications and Release Surface Herbs
Allergy drugs suppress allergic reactions and often have an astringent property whereas acrid and warm herbs commonly used in the treatment of allergies open the pores and release the wind.
Dimenhydrinate (Dramamine), cetirizine, loratadine, and chlorpheniramine are common over-the-counter antihistamines. Levocetirizine (Xyzal) and fexofenadine (Allegra) are prescription anti-histamines. Anti-histamines are distinguished by degrees of sedation and patients react differently to anti-histamines. Loratadine provides non-sedating, short-term symptomatic relief.
Ma Huang (Herba Ephedrae) opens the Lung, releases surface and encourages sweating. Ma Huang stimulates the central nervous system (CNS) and the cardiovascular system and therefore should not be combined with drugs of a similar nature such as ephedrine, pseudoephedrine (Sudafed), caffeine, and MAO inhibitors. Ma Huang may also reduce the effects of beta blockers such as metoprolol (Lopressor, Toprol) and propranolol (Inderal) because Ma Huang increases levels of norepinephrine.
Gui Zhi (Ramulus Cinnamomi Cassiae) warms the channels to release the surface and causes sweating.
Fang Feng (Radix Ledebouriellae Diaricatae) and Jing Jie (Schizonepetae Herba) release the surface and cause... (more in course materials)
A 43 year old female patient has chicken pox. During the first two weeks she took cetirizine and the chicken pox rash persisted but did not fully express. The tongue is puffy with a white coating and the pulse is floating and slippery.
Wind damp heat attack
Fang Feng (Radix Ledebouriellae Diaricatae), Jing Jie (Schizonepetae Herba,) and Niu Ban Zi (Fructus Arctii Lappae). The chicken pox expressed after taking the herbs and began diminishing within two days. Fang Feng and Jing Jie encourage wind dampness to the surface to release damp toxins and Niu Ban Zi releases the surface and clears heat toxins.
The patient had an acute external wind damp attack and used anti-histamines which suppressed and trapped the evil within the body. The anti-histamines did not allow the pathogens to release outwardly. Release surface herbs pushed the pathogens out of body and therefore the chicken pox released and expressed... (more in course materials)