The ultimate point of taking medication is to fix problems in the body, whatever those problems may be. Human technology has gotten to the point where we have at least one drug for ailment that affects every system in the body. We have muscle relaxants for the muscular system, as well as variant formulas for those muscle relaxants which are designed to target the skeletal system. For mental disorders, we have a host of psychoactive drugs that affect the central nervous system and the neural chemical receptors it uses. We have medications that help provide relief for problems with our digestive and excretory systems. There are medications dedicated to solving problems with sexual health. Walk into any pharmacy and you'd see migraine remedies and skin treatments galore. However, in this weird, drugged world we live in, we are never allowed to mix medications, to avoid negative drug interaction.
This is, of course, a perfectly reasonable stipulation to our current situation. Certain drugs have certain compounds in them, and said compounds can interact rather poorly with other compounds, which may be present in other drugs. Basic chemistry tells us that some compounds, when put together, do not react in very pleasant ways. An example of this would be when an acid and a base are combined, which can generate a wide range of effects, depending on the pH levels of the two. For other compounds, they simply cannot be made to mix with each other unless you throw in some sort of catalyst. However, in some cases, something in the blood can act as a catalyst, resulting in some unpleasant side effects for your body.
The fact is, doctors like to grill you on your medication history to determine whether or not the drugs he's planning to prescribe for you might cause side effects when mixed into your bloodstream. Certain drugs can react poorly with others, though the two do not always have to be the same type. For example, muscle relaxants that target the central nervous system might react poorly with migraine remedies that works in the same manner. Medications for heart conditions can sometimes cause trouble with sexual health and erectile dysfunction treatments.
Drug interaction problems can range from being mild annoyances to being potentially lethal. Pain killers and muscle relaxants, for example, work in very similar ways and combining the two can potentially cause permanent loss of mobility. The same is generally true of any psychoactive medications, such as anti-anxiety medication, some migraine remedies, and anti-depressants. Anything that affects or alters the heart rate of the body can also cause problems when combined with heart medication, for obvious reasons. The skin can also experience negative drug interaction scenarios, such as when benzoyl peroxide and salicylic acid (two of the many common ingredients of acne treatments) are applied at the same time.
Doctors are generally well aware of the potential dangers of negative drug interaction scenarios. That is the reason for them drilling their patients on their medication history, as it will provide the doctor a better idea of what might be in your bloodstream. The better informed your doctor is of what your prescription might encounter inside your body, or even on the surface of the skin, can it easier for him to find medicine that will minimize the chances of side effects.