Phentermine is a diet suppressant available with a doctor’s prescription under the brand names Adipex-P, Ionamin, Obenix, Oby-Cap, Teramine and Zantryl. Like amphetamines, phentermine stimulates the central nervous system. Like many medications, phentermine has various side effects, including some that may affect your ability to remain properly hydrated. Because dehydration can be life-threatening, it’s important to understand phentermine’s effects on hydration.
Vomiting and diarrhea are two common side effects of phentermine usage, according to Drugs.com. Both of these side effects result in dehydration, which means that the body does not have a sufficient amount of water. Phentermine is only meant to be taken for a short amount of time, such as a few weeks, notes the website. If taken for longer and these side effects persist, you could become severely dehydrated.
Dysuria is painful and frequent urination caused by inflammation or stricture of the urethra, according to the Merck Manuals Online Medical Library. In people taking phentermine, dysuria is the result of increased bladder sphincter tone, notes information provided by the International Programme on Chemical Safety. Frequent urination can lead to dehydration if a phentermine user does not make an effort to replace lost fluids.
Because a common side effect among people taking phentermine is dry mouth, individuals may try to counteract the side effect by drinking extra fluids. Overhydration can have serious consequences because it results in an imbalance of sodium in the body. For instance, people may become confused or experience seizures, according to the Merck Manuals Online Medical Library. This condition is much more common among those who do not excrete urine normally. Unfortunately, phentermine use can result in abnormal urine excretion, putting users at increased risk of overhydration.
Conversely, some phentermine users may experience acute urinary retention, or ischuria, according to the International Programme on Chemical Safety. This means that fluids going into the body are not coming out at the same rate. Prolonged ischuria can result in the complete inability to urinate. This is a medical emergency that can lead to bladder damage and acute renal failure. Instead of continuing to drink fluids in an attempt to force the body to urinate, seek emergency treatment.