Half-life and stready state: A 2-hour half-life me
Post# of 72440
"When the patient is taking a medication on a regular basis, there is an ongoing process of drug absorption in the form of each dose of the drug and, concurrently, an ongoing process of drug removal with the drug's metabolism and clearance. Eventually, there comes a point when the amount of drug going in is the same as the amount of drug getting taken out. We call this "steady state." It takes somewhere between 5 and 6 half-lives for a medication to reach steady state. Thus, medications with short half-lives reach steady state relatively quickly, while those with long half-lives take a long time to reach steady state.
http://www.medscape.com/viewarticle/448250_3
For those of you who still don't understand steady state, the following analogy using a carton of eggs should help.
"Another way to think of this is imagine a carton of eggs in your kitchen. And imagine that when you use 2 eggs to make an omelette for breakfast. Someone in your house notices the empty spots in the carton of eggs and purchases 2 more eggs and places them in the carton. So when you wake up the next morning, the carton is full of eggs. If this process repeats itself over many days, it would appear that the eggs never change … there are always 12 eggs in the carton even though you use them for various meals and recipes. In this hypothetical scenario, the eggs are at steady state because the rate of elimination is equal to the rate of input."
https://www.certara.com/2013/11/25/understand...okinetics/
Patients can take oral K three times a day to maintain continuous exposure in the circulatory system. Also, its bioavailability of 80% is excellent.
Let's say the starting dosage is 750 mg. 80% bioavailability equals 600 mg. Since the half-life is two hours, 300 mg of K still exists in the body after two hours. 300 mg is still well within the efficacy range. In the K-OC trial, cohort 1 is 250 mg and cohort 2 is 350 mg. The use of modified-release dosage should further improve K's efficacy.