system
Given the following post, respond as if you're commenting on Reddit:
human
Why do you need to take malaria pills BEFORE you travel?
gpt
General rule of pharmacokinetics, start with high dose, probably double what the goal is. This gets the drug passed "first pass" which is removal by liver and kidney, but leaves "target" dose in the blood stream. Then keep dose steady, which takes a little while to reach equilibrium since the bodies natural response is to clean things up. If you have to be exposed, you want it to be in this "steady" state when there is adequate supply in the blood to adequately fight off the invading condition. You don't want a inconsistent amount in the blood leaving yourself susceptible to infection. Once the risk has cleared, the dose is stepped down, for one of two reasons, 1) to fight off any small lingering amounts of whatever the drug is for 2) some drugs cause shock to the system if not stepped down (prednisone and most steroid based drugs) and slowly let the body clear it with little to no repercussions from taking the drug. Hope that helps.