Excretion of medicinal substance or its metabolites from the body is carried out by all excretory organs (kidneys, intestines, lungs, dairy, salivary, sweat glands, etc.). The medication effects could be gone even though it is still in your system. Most drugs offered by My Canadian Pharmacy have a half-life of about 24 hours, so they are excreted within 4-5 days. Only several medications have very long half-lives.
The main body of removing drugs from the body are the kidneys. Excretion of medication by the kidneys occurs by filtration and with the help of active or passive transport. Lipoid-soluble substances are easily filtered in the glomeruli, but in the tubules, they are passively absorbed again. Drugs, which are poorly soluble in lipids, are more rapidly excreted in the urine since they are poorly reabsorbed in the renal tubules. Acid reaction of urine helps to eliminate alkaline compounds and makes excretion of acidic. Therefore, in case of intoxication with drugs of an acidic nature (for example, barbiturates), sodium bicarbonate or other alkaline compounds are used, and during intoxication with alkaloids having an alkaline character, ammonium chloride is used.
It is also possible to accelerate the excretion of drugs from the system by prescribing potent diuretics, such as osmotic diuretics or furosemide, against the background of the introduction of large amounts of fluid into the body (forced diuresis). Excretion of bases and acids from the body occurs through active transport. This process goes with the expenditure of energy and with the help of certain enzyme carrier systems. By creating competition for a carrier with any substance, it is possible to slow the elimination of the drug (for example, etamid and penicillin are secreted using the same enzyme systems, therefore etamid slows down the elimination of penicillin).
Drugs that are poorly absorbed from the gastrointestinal tract, are removed by the intestines and are used in gastritis, enteritis, and colitis (for example, astringents, some antibiotics used in intestinal infections). In addition, from the liver cells, drugs and their metabolites enter the bile and enter the intestine, from where they are either re-absorbed, delivered to the liver, and then are excreted from the body with feces. Direct secretion of a number of drugs and their metabolites by the intestinal wall is not excluded.
Volatile substances and gases are removed through the lungs (ether, nitrous oxide, camphor, etc.). To accelerate their excretion, it is necessary to increase the volume of pulmonary ventilation.
Many drugs can be excreted with milk, especially weak bases and non-electrolytes, which should be considered when treating nursing mothers.
Some medicinal substances are partially excreted by the glands of the mucous membrane of the oral cavity, providing a local (eg, irritating) effect on the ways of excretion. Thus, heavy metals (mercury, lead, iron, bismuth), being distinguished by salivary glands, cause irritation of the oral mucosa and causes stomatitis and gingivitis. In addition, they cause the appearance of a dark border along the gingival margin, especially in the area of carious teeth, which is caused by the interaction of heavy metals with hydrogen sulfide in the oral cavity and the formation of practically insoluble sulfides. Such a “fringe” is a diagnostic sign of chronic heavy metal poisoning.
With prolonged use of diphenyl and sodium valproate (anticonvulsant drugs), irritation of the gingival mucosa may be the cause of hypertrophic gingivitis (“diphenyl gingivitis”).