What is ion trapping in pharmacology give an example?
Ion trapping is the reason why basic (alkaline) drugs are secreted into the stomach (for example morphine), where pH is acidic, and acidic drugs are excreted in urine where the conditions are alkaline.
What is ion trapping in aspirin?
Because aspirin is a weak acid, it ionizes when exposed to a basic environment, such as alkaline urine. Ions are poorly reabsorbed in the tubules and are excreted more readily. This phenomenon is called ion trapping and also works well for overdoses of other weak acids, such as phenobarbital.
What does it mean when a drug is ionized?
Ionized (or charged) drugs are not absorbed as efficiently as un-ionized drugs are. Practically speaking, this means that if taken orally, a drug that is a weak acid will be absorbed primarily in the acidic environment; whereas, a drug that is a weak base will be absorbed in the alkaline environment small intestines.
Why are ions trapped?
The ion trap functions as a mass spectrometer when the trapping field is changed, so that the trajectories of simultaneously trapped ions of consecutive specific mass/charge ratio become sequentially unstable, and ions leave the trapping field in order of mass/charge ratio.
What is ionized and unionized drugs?
Most drugs are weak acids or bases that are present in solution as both the ionized and unionized forms. Ionized molecules are usually unable to penetrate lipid cell membranes because they are hydrophilic and poorly lipid soluble. Unionized molecules are usually lipid soluble and can diffuse across cell membranes.
Is acidic drugs are ionized at acidic pH?
Ionization of Drugs. Most drugs are weakly acidic or basic substances and are thus ionized at physiologic pH. Passive diffusion across lipophilic membranes depends on the degree of ionization.
What happens during ionization?
Ionization is the process by which ions are formed by gain or loss of an electron from an atom or molecule. If an atom or molecule gains an electron, it becomes negatively charged (an anion), and if it loses an electron, it becomes positively charged (a cation). Energy may be lost or gained in the formation of an ion.
What is pH trapping?
Ion trapping alters the urine pH to inhibit reabsorption of toxins across the renal tubular membranes. The principle behind this approach is to “trap” the toxin in its ionized form in the urine where it can be excreted.
What is the difference between ionized and unionized?
Ionized molecules are usually unable to penetrate lipid cell membranes because they are hydrophilic and poorly lipid soluble. Unionized molecules are usually lipid soluble and can diffuse across cell membranes.
What is ion trapping in pharmacology?
(Pharmacology) Conditions which favour the non ionised form of drug, enhance the drug permeation (absorption). Contrarily, conditions that favour ionisation will restrict the translocation of weak electrolytes since proportions existing as diffusible form is low. This leads to a phenomenon called as ion trapping.
What is the role of ionization in drug transport?
Ion trapping may be responsible for the transport of certain drugs from the seminal plasma to the genitourinary tract. Drug ionization depends on the pH difference between plasma (pH 7.4) and prostaic fluid (pH 6.6), the latter of which can trap basic drugs in the prostate.
When is ion trapping contraindicated in the treatment of drug toxicity?
Ion Trapping. Ion trapping is contraindicated when the toxicant has a large volume of distribution, is strongly protein bound, is highly lipid soluble, and is cleared primarily by tissue or hepatic metabolism.
How does ion trapping work in urine?
Ion trapping alters the urine pH to inhibit reabsorption of toxins across the renal tubular membranes. The principle behind this approach is to “trap” the toxin in its ionized form in the urine where it can be excreted.