pharmacokinetics

Codeine: Drug Effects, Side Effects, Dosage and Uses

Products Codeine is available alone or in combination with other active ingredients in the form of tablets, effervescent tablets, capsules, dragées, syrups, drops, bronchial pastilles, and as suppositories. It is also combined fixedly with acetaminophen for the treatment of pain (see under codeine acetaminophen). Structure and properties Codeine (C18H21NO3, Mr = 299.36 g/mol) is -methylated … Codeine: Drug Effects, Side Effects, Dosage and Uses

Elimination

Introduction Elimination is a pharmacokinetic process that describes the irreversible removal of active pharmaceutical ingredients from the body. It is composed of biotransformation (metabolism) and excretion (elimination). The most important organs for excretion are the kidney and the liver. However, drugs can also be excreted through the respiratory tract, hair, saliva, milk, tears, and sweat. … Elimination

Pregabalin

Products Pregabalin is commercially available in capsule form and as an oral solution (Lyrica, generics). It was approved in the United States and EU in 2004 and in many countries in 2005. Structure and properties Pregabalin (C8H17NO2, Mr = 159.2 g/mol) exists as a white crystalline powder that is soluble in water. It was developed … Pregabalin

First-Pass Metabolism

The effect of the first liver passage For a perorally administered pharmaceutical agent to exert its effects at the site of action, it usually must enter the systemic circulation. To do so, it must pass through the intestinal wall, the liver, and part of the circulatory system. Despite complete absorption in the intestine, the bioavailability … First-Pass Metabolism

Cytochrome P450 (CYP)

CYP450 Cytochromes P450s are a family of enzymes that are of paramount importance in drug biotransformation. The most important isoenzymes for drug metabolism are: CYP1A1, CYP1A2 CYP2B6 CYP2C9, CYP2C19 CYP2D6 CYP2E1 CYP3A4, CYP3A5 and CYP3A7 The number after the abbreviation CYP stands for the family, the following letter for the subfamily and the last number … Cytochrome P450 (CYP)

Metabolism (Biotransformation)

Introduction Biotransformation is an endogenous pharmacokinetic process that leads to a change in the chemical structure of active pharmaceutical ingredients. The organism’s general goal in doing so is to make the foreign substances more hydrophilic and to direct them to excretion via the urine or stool. Otherwise, they could be deposited in the body and … Metabolism (Biotransformation)

Dose Adjustment in Renal Insufficiency

Elimination at the kidney The kidneys, along with the liver, play a central role in the elimination of pharmaceutical agents. They can be filtered at the glomerulus of the nephron, actively secreted at the proximal tubule, and reabsorbed at various tubular segments. In renal insufficiency, these processes are impaired. This may result in a renally … Dose Adjustment in Renal Insufficiency

Tolcapon

Products Tolcapone is commercially available in the form of film-coated tablets (Tasmar). It has been approved in many countries since 1997. Structure and properties Tolcapone (C14H11NO5, Mr = 273.2 g/mol) exists as a yellow, odorless, non-hygroscopic, crystalline powder. It is a nitrobenzophenone. Effects Tolcapone (ATC N04BX01) affects the pharmacokinetics of levodopa. The effects are due … Tolcapon

Pharmacokinetics: Treatment, Effects & Risks

The term pharmacokinetics covers all the processes to which drugs are subject in the body. This involves the action of the body on the pharmaceuticals. In contrast, the influence of the active ingredients on the organism is referred to as pharmacodynamics. What is pharmacokinetics? The term pharmacokinetics covers all the processes to which the drugs … Pharmacokinetics: Treatment, Effects & Risks

Interactions

Definition When two or more drugs are combined, they may affect each other. This is especially true with regard to their pharmacokinetics (ADME) and effects and adverse effects (pharmacodynamics). This phenomenon is called interaction and drug-drug interaction. Interactions are usually undesirable because they can lead to, for example, loss of efficacy, side effects, poisoning, hospitalization, … Interactions

Auxiliary Materials

Definition On the one hand, drugs contain the active ingredients that mediate the pharmacological effects. On the other hand, they consist of excipients, which are used for the production or to support and regulate the drug effect. Placebos, which consist only of excipients and contain no active ingredients, are an exception. Excipients can be of … Auxiliary Materials

Divisibility of Tablets

Flexible dosage By dividing, the fixed dose of tablets can be changed, which increases flexibility. This is because a dose reduction may be necessary for children, for patients with renal insufficiency, for drug interactions, or for altered drug metabolism. Tablets are also divided for economic reasons. For example, the duration of therapy may be doubled … Divisibility of Tablets