It is always better to find professional advice. However, if you need to medicate right then, it is advisable to take one dose and wait to see if that does the trick. If it fails to move the problem, which is of crisis dimensions, then take another after perhaps 15 minutes. You can generally repeat this for a good 5 or 6 doses, after which you either know the wrong remedy has been selected, or the problem is bigger than you thought. Some authorities suggest stopping after 10 doses, but to me that seems a lot. As soon as a medication starts to work, it is advisable to stop any further doses, until the remedy stops working. The above information mostly applies to acute, or suddenly-appearing problems. Longer term, or chronic problems, often require only one dose, and perhaps a top-up, days, or weeks or months later.