Adjuvant is a pharmacological adjuvant that enhances the effect of the drug administered together with it. It usually has little or no pharmacological effect itself.
What is an adjuvant?
The term adjuvant is derived from the Latin verb adjuvare, which means to help. Adjuvants are administered together with a reagent that would have no effect or only a weak effect on its own. Adding an adjuvant to the drug increases the effect. For example, it may occur more quickly, be more pronounced, or the level of effect in the tissue may be maximized, which in turn may result in an improved effect. A common example of adjuvants are penetration accelerators, which ensure that pharmacologically active substances can penetrate membranes more quickly and in greater quantities. An adjuvant is not the same as adjuvant therapy. The adjuvant is always added to the active substance itself or administered directly together with it in order to influence its efficacy. Adjuvant therapies, on the other hand, are different forms of therapy used in parallel, with adjuvant treatment being an adjunct to a main therapy.
Pharmacologic action
Adjuvants themselves should have as little effect as possible on the body and organs and should have as little effect as possible on the properties of the drug they are reinforcing. Ideally, they affect only the drug with which they are co-administered. For example, an adjuvant can ensure that an active ingredient acts more quickly because its concentration in the tissue increases or it can penetrate inhibitory membranes more readily. Chemically, adjuvants are often solutions and emulsions. Such adjuvants must be distinguished from active ingredients used in adjuvant therapy, which are also referred to as adjuvants. These are indeed pharmacologically active, which is the purpose of this form of therapy.
Medical application and use for treatment and prevention.
Adjuvants are found in almost every drug dosage form. Almost every patient is familiar with them through headache tablets, for example. Substances such as lysine and caffeine ensure that active ingredients such as ibuprofen or paracetamol work better and faster because they can penetrate the tissue at higher concentrations. Caffeine is already considered an adjuvant therapy, as the substance dilates the vessels and further supports the effect of the actual active ingredient. Adjuvants can also be administered intravenously, for example by infusion or by giving a single injection. They are used, for example, to absorb vaccines against influenza, tetanus, diphtheria, or hepatitis A. In these cases, aluminum hydroxide is used as an adjuvant. In this form, the adjuvants influence the immune system in such a way that it becomes particularly receptive to the vaccine.
Risks and side effects
Adjuvants should be as free of side effects and interactions as possible. In practice, this cannot always be guaranteed, and so with any drug it must be taken into account that the adjuvant it contains may have side effects. The aluminum hydroxide used in vaccines in particular has repeatedly come under heavy public criticism, although it has not yet been possible to prove whether it really poses the risks attributed to it. These suspected side effects include, for example, ADHD or later Alzheimer’s disease and dementia. The adjuvant aluminum hydroxide in particular is risky because it triggers inflammation at the injection site, which increases the number of immune cells in the area so that the active ingredient is utilized by them to a greater extent. However, it is hardly degradable and can remain in the body of the vaccinated patient for a very long time, where it could also trigger infections in the future. For each adjuvant, it is important to consider whether the patient has already had contact with the substance and whether hypersensitive or dangerous reactions have occurred. The attending physician will ask about this before the drug with the adjuvant may be administered to the patient.
