Obesity is fast growing into an international medical problem due to the sheer number of people who are growing very fat. It not only makes one look like a bloated balloon but starts gnawing at one's health from inside.

The results can be life threatening. That's the reason why in certain situations it becomes imperative for the doctors to fight obesity with drugs. The drugs so used are called 'anti-obesity' drugs and seek to reduce weight fast. These drugs are designed to alter a fundamental body process and are therefore prescribed only when there is no alternative available and it is only through steep weight loss that a person can be saved.

Anti-obesity drugs work by suppressing the appetite so that one doesn't feel hungry at all and has no urges to eat. Once one is on this kind of medication, one might turn into an ascetic from a glutton. Alternatively, a drug may also work by speeding up body's metabolism in which case what eats would be quickly digested and disposed of without a great deal of absorption or retention.

Another way that an anti-obesity drug might take is by interfering with the absorption of nutrients in food. For instance, a drug may affect one's fat absorption, wherein despite eating substantial amount of food one would absorb no fat.

However, it may seem such an easy way to shed weight, but before you pester your doctor for prescribing anti-obesity drug for you, beware there are some very severe and many a time lethal side effects that you should also be considered.

Most of these side effects are associated with the drugs' operational mechanism. Generally speaking, these are stimulants that carry a considerable risk raising the high blood pressure. They may also trigger increased heart rate, cause closed-angle glaucoma, restlessness or insomnia.

Some of the drugs in this category like Orlistat prevents the absorption of fat which may cause troublesome bowel movements, flatulence, oily stools coupled with severe stomach pain.

The problem here is that these drugs interfere with appetite while we are still not through with understanding the neural mechanism of it. This might cause unforeseen problems. As we all know, appetite is one of the most basic survival instincts. An interference with it may involve a high mortality risk, for which reason it may be disadvantageous or even plainly dangerous to push it into clinical use.

Besides, all the side effects of such drugs are not known. So, consider it as an option only when you don't have any other.