The pharmacological effects of caffeine are similar to those of other methylxanthines (including those found in various teas and chocolates). This wide range in the plasma mean half-life of caffeine is due to both innate individual variation, and a variety of physiological and environmental characteristics that influence caffeine metabolism (e.g., pregnancy, obesity, use of oral contraceptives, smoking, altitude). However, caffeine's elimination half-life may range between 1.5 and 9.5 hours, while the total plasma clearance rate for caffeine is estimated to be 0.078 L/h/kg (Brachtel and Richter, 1992 Busto et al., 1989). The mean half-life of caffeine in plasma of healthy individuals is about 5 hours. Structurally, caffeine (and the other methylxanthines) resembles the purines. ![]() In pure form, it is a bitter white powder. This chapter provides a brief summary of the metabolism and physiological effects of caffeineĬaffeine (1,3,7-trimethylxanthine) is a plant alkaloid with a chemical structure of C 8H 10N 4O 2 (see Figure 2–1) and a molecular weight of 194.19. It has numerous pharmacological and physiological effects, including cardiovascular, respiratory, renal, and smooth muscle effects, as well as effects on mood, memory, alertness, and physical and cognitive performance. This helps preserve drug efficacy and avoid unwanted side effects.As stated in Chapter 1, caffeine is the most widely used central nervous system (CNS) stimulant in the world. You can also use the drug elimination calculator to simulate loading doses, as some drugs need weeks of taking to reach optimal levels in your body.Īnd last but not least, you can limit drug interactions, as you know how much drug is left in the body at the time of the second administration. With this knowledge, you quickly establish a dose and administration schedule. It happens when you consume the same amount of drug that's eliminated from the body.įor all of the above, knowing how much of the drug is left in your body and how it compounds is necessary. The drug needs to remain at a constant level (be in a steady state) during treatment to produce the desired effect. Titration increases the dose for maximum benefit without side effects. But decrease it too slowly, and you suffer side effects unnecessarily long. Decrease it too quickly, and you experience withdrawals. When tapering, you gradually decrease the dose of medication to stop using it. This is irreplaceable knowledge for tapering, titrating, or reaching a steady state. You can maintain a minimum effective level of drug in the body by adjusting your doses or their frequency. Half life helps you evaluate how often to take the drug to maximize effects and minimize adverse reactions. That's when most drugs no longer have any effect. You can consider the drug eliminated when about 97% of it is gone. Hover on the graph to get a precise amount of drug left at any time. Residuals - how much drug is left in your body.Time - how much time has passed since you've first taken the drug.Once you enter the required data for at least one ingestion, the graph shows the results: You can add unlimited ingestions to track multiple drugs or repeating doses of the same one. Offset (optional) - how long after the initial administration you took another dose.Select a drug from the list of suggestions to fill it out automatically. It can be anything, but half life for common drugs is auto-filled. Try a demo to get an idea of how it works. Use it to keep constant levels of medicine in the body, or avoid unwanted interactions between substances. It does so by looking at the elimination half life of a medication. This drug concentration calculator is an easy tool to determine the amount of substance left in your system.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |