Related Concept Videos

Prevention of Further Absorption of Poison01:14

Prevention of Further Absorption of Poison

In cases of acute poisoning, the primary objective is to prevent further absorption of the toxic substance into the body. Immediate interventions using various decontamination techniques targeting the gastrointestinal (GI) tract can achieve this. Decontamination is crucial to prevent poison from entering the systemic circulation, which involves washing affected areas with water and mild soap and removing contaminated clothing. Once external decontamination is done, attention must be turned to...
Drug Elimination: Non-Renal Routes01:23

Drug Elimination: Non-Renal Routes

The liver plays a pivotal role in eliminating drugs and their metabolites, primarily through a process known as biliary excretion. This process involves the hepatocytes, the primary cells in the liver that generate bile. A range of transporters actively expels polar drugs or hydrophilic drug metabolites into the bile, which transports the drugs and metabolites into the small intestine. From here, they are eventually expelled from the body through feces. In some instances, the original drug or a...
Enhanced Elimination of Poison01:26

Enhanced Elimination of Poison

Poison can be effectively removed from the gastrointestinal (GI) tract through various decontamination procedures.
Antidotes serve a crucial role in counteracting the effects of poison by inhibiting enzymes responsible for producing harmful drug metabolites. In some cases, these toxic metabolites can be neutralized by endogenous cosubstrates, which are maintained at specific concentrations to prevent interaction with cellular macromolecules and subsequent cell death.
Renal excretion is the...
Factors Influencing Drug Absorption: Presystemic Elimination01:24

Factors Influencing Drug Absorption: Presystemic Elimination

The pharmacokinetic journey of oral drugs begins with a crucial first pass through the hepatic portal system, called the first-pass effect. This first pass significantly impacts bioavailability — the proportion of a drug that enters systemic circulation and is available for therapeutic action. The primary route sees the drug absorbed by intestinal membranes and then shunted to the liver via the hepatic portal vein. Here, pre-systemic elimination occurs as drugs face metabolism or biliary...
Drug Excretion: Miscellaneous Routes01:10

Drug Excretion: Miscellaneous Routes

Drug excretion involves various organs, including the liver, intestines, skin, and eyes. In the case of drugs or toxins, they can be actively secreted into bile by transporters in the hepatocyte's canalicular membrane. These substances enter the GI tract during digestion and may be reabsorbed into the body from the intestine. This process, known as enterohepatic recycling, can significantly prolong the presence and effects of a substance in the body. To interrupt this cycle, specific substances...
Toxicity Testing in Animals01:23

Toxicity Testing in Animals

Toxicity tests in animals are grounded on two main assumptions: first, the effects observed in laboratory animals can be extrapolated to humans, especially when adjusted for body surface area; second, high-dose exposure in animals is essential to identify potential human hazards from lower doses. This is based on the quantal dose-response concept, which faces the challenge of extrapolating results from relatively few test animals to much larger human populations. For example, a 0.01% incidence...