Systemic uptake

With systemic absorption , in contrast to topical application , medicinal substances are transferred into the blood and / or lymphatic system of the body (hence “systemic”) and distributed throughout the body.

Absorption

In order to be able to develop their effect in the entire system (body), drugs must be absorbed, for example in the digestive tract, via epithelium . A distinction is made between passive absorption by osmosis and more active by means of permeases . In both cases, biological membranes will penetrate. The rate of absorption depends on various factors:

Disintegration of the dosage form and dissolution of the active ingredient
Lipophilicity and water solubility of the active ingredient
Application location

The following factors also play a role in the case of orally administered drugs:

Peristalsis of the stomach and intestines (possibly influenced by the drug)
existing food in the stomach and intestines
existing drugs
Health status of the patient (in particular diseases of the gastrointestinal tract)

Lipophilic active ingredients can usually penetrate cell membranes more easily. Many drugs are both lipophilic and hydrophilic in order to allow a particularly even distribution.

If the active ingredients are absorbed in the gastrointestinal tract, they first reach the liver via its venous blood vessel system, where a chemical change takes place ( first-pass effect ). This change has a considerable influence on the effect of the drug (see metabolism and bioavailability ). After absorption has taken place, the active ingredients are distributed in the flowing blood in the organism.

Demarcation

The strict separation between systemic and local ( topical ) drug therapy cannot always be maintained in practice, since active ingredients can also be absorbed via the skin and get into the blood and lymphatic systems even with local therapy. This must be taken into account in particular with large wounds.

Side effects

Systemic uptake of drugs can be a cause of drug side effects . So is z. For example, acetylsalicylic acid (aspirin) is known to have a pain-relieving effect (desirable effect), but also passes through the bloodstream to the kidneys and gastric mucous membrane . Long-term use of aspirin may cause undesirable effects such as kidney bleeding and stomach upset.

literature

Nicole Menche: Internal Medicine: Textbook for Nursing Professions. Urban & Fischer, 2007. ISBN 978-3-43726961-5 . P. 27f.

Individual evidence

^ ^A ^b ^c Nicole Menche: Internal medicine: textbook for nursing professions. Urban & Fischer, 2007. ISBN 978-3-43726961-5 . P. 27f.
↑ ^a ^b ^c ^d Christine Fiedler, Bettina Raddatz (ed.): Study Nurse / Study Assistance: The Compendium for Further Education and Practice. Springer, 2015. ISBN 978-3-662-45422-0 . P. 96ff.
^ Ilka Köther: Thiemes Altenpflege. Thieme, 2007. ISBN 978-3-13139132-2 . P. 534
↑ Frederick Meyers, Ernest Jawetz, Alan Goldfien: Textbook of Pharmacology: For students of medicine of all degrees and for doctors. Springer, Berlin and Heidelberg 1975, ISBN 3-540-07356-6 . P. 328

[menche-1] A ^b ^c Nicole Menche: Internal medicine: textbook for nursing professions. Urban & Fischer, 2007. ISBN 978-3-43726961-5 . P. 27f.

[fiedler-2] Christine Fiedler, Bettina Raddatz (ed.): Study Nurse / Study Assistance: The Compendium for Further Education and Practice. Springer, 2015. ISBN 978-3-662-45422-0 . P. 96ff.

[3] Ilka Köther: Thiemes Altenpflege. Thieme, 2007. ISBN 978-3-13139132-2 . P. 534

[4] Frederick Meyers, Ernest Jawetz, Alan Goldfien: Textbook of Pharmacology: For students of medicine of all degrees and for doctors. Springer, Berlin and Heidelberg 1975, ISBN 3-540-07356-6 . P. 328