Morphine is a commonly used general narcotic pain reliever. There is nothing in morphine itself that will make you lose weight, but its side effects may cause weight loss. You may lose weight due to secondary effects including nausea, decreased appetite and changes in the way food tastes. And if you are addicted to the drug, your weight loss could be dramatic and even life-threatening.
What Morphine Does
Morphine is a narcotic analgesic that works by binding to receptors in the brain that control pain signals. In addition to controlling pain, morphine is also an effective cough suppressant. The downside to taking morphine is that you can quickly become physically addicted to it and also become addicted to the euphoric high it produces. And like many narcotics, it produces a range of side effects, some of which can lead to weight loss.
Nausea and Loss of Appetite
Like many analgesics, morphine can cause nausea and loss of appetite. If you have a problem with nausea when you take morphine, chances are you will lose some weight while you are taking the drug, though your body may adjust to the morphine over time and the nausea may disappear. You can also take drugs to control the nausea but this often makes morphine less effective in controlling pain.
Another side effect you may experience with morphine is vomiting. It's believed that morphine causes vomiting because of its effect on the chemoreceptor trigger zone in the brain when it binds with pain receptors. This in turn triggers a vomiting reflex in the brain. Nausea and vomiting affects up to 50 percent of people who take morphine so there's a chance you may lose weight due to these factors.
Changes in the Taste of Food
One of the less common side effects you may experience with morphine is a change in the way that food tastes. It's not clear what morphine does to create this effect, but you may notice that food tastes differently after you have taken morphine and the change may cause you to eat less and lose weight.
If you become addicted to morphine, you will probably lose weight, though that may be the least of the problems you'll encounter. The side effects of addiction take many forms but they generally include a lethargy that decreases the appetite and makes you less interested in eating. And if you withdraw from the drug, vomiting and diarrhea are common symptoms, which will definitely make you lose weight.