The issue of weight loss and body fat reduction is a challenge for most people who seek to achieve this goal. But add in the possibility of drug induced weight gain and the challenge can sometimes seem impossible to overcome. Often times, this is overlooked as the culprit of unexplained weight gain or the inability to lose weight despite being on a good program of wise nutrition and proper exercise.

There are many reasons why this problem goes unrecognized in may people who suffer from this unwanted side effect. Quite often the listing of weight gain as a side effect is not clearly noted in the printed materials and label that accompany a specific drug. Doctors may not be aware of weight gain as a side effect of a specific drug when writing a prescription for it. Also, if a drug is new to the market it may not even be known that weight gain is a side effect in certain patients until actual usage reports start coming back to the pharmaceutical company who produces that drug.

There are also interaction side effects between certain drugs that may lead to weight gain - where the drugs by themselves don't cause weight gain but together they do.

Now, we must understand that each person has a unique biochemical profile, generally speaking, and because of this - not everyone reacts the same to certain elements that are put into the body. However, there are certain groups of drugs that are known to cause weight gain in a certain percentage of patients who are taking one or more of those drugs.

Certain prescription drugs used to treat mood disorders, seizures, migraines, diabetes, and even high blood pressure can cause weight gain - sometimes 10 pounds a month. Some steroids, hormone replacement therapy, and oral contraceptives can also cause unwanted pounds to creep up on you.

Steroids such as prednisone, older antidepressants such as Elavil and Tofranil, and second-generation antipsychotics like Zyprexa are the biggest -- and most recognized -- promoters of weight gain. Some other common offenders include the antidepressants Paxil and Zoloft, the antiseizure medication Depakote, diabetes drugs like Diabeta and Diabinese, and the high blood pressure drugs Cardura and Inderal. Heartburn drugs like Nexium and Prevacid may also cause drug-induced weight gain.

An important note here is that it is not always the drug itself that is causing the weight gain. For example, when antidepressants bring a person to a state of less depression and their moods and attitudes improve - many times so does appetite, and hence there is an increase in daily caloric intake. If there is no increase in physical activity - those extra calories show up in the form of body-fat.

Other mechanisms have more to do with changes in metabolic efficiency via thyroid/brain functionality. Another factor may be fluid retention and edema. In this case a drug causes the patient to store a higher capacity of water in areas of the body where fluids did not accumulate before the drug was present in the body.

While some drugs used to treat depression and other mood disorders can cause weight gain, the antidepressants Wellbutrin and Prozac tend to help people lose weight. Some medications used to treat seizure disorders and headaches, such as Zonegran and Topamax are good alternatives that are both associated with weight loss.

The single most important factor you want make a priority when starting to take a prescribed medication is awareness. Know what all the effects can be of that specific drug and make it a point to discuss alternatives with your doctor in the case of you experiencing any unexplainable side effects - such as weight gain.

As I've pointed out above - there are certain drugs that can be used to treat the same ailment but give you the opposite side effect. Again, biochemistry and some 'trial and error' will play a part here. But as long as you are aware of your starting point and make note of any changes on a regular basis - you will have the right feedback to know what your next move should be - if any is necessary at all.