Does Pristiq Cause Low Sodium Levels? (+3 risk factors)

In this article, we will discuss whether Pristiq causes low sodium levels. We will also discuss how Pristiq affects sodium levels in the body, the risk factors increasing the chance of low sodium while taking Pristiq, and other related information. 

Does Pristiq Cause Low Sodium Levels? 

Yes, Pristiq can cause low sodium levels in your body. Pristiq is the brand name for desvenlafaxine and is manufactured by Pfizer. Low sodium levels are mentioned as a possible side effect of Pristiq by Pfizer in the medication guide (1). 

Pristiq is a serotonin-norepinephrine reuptake inhibitor (SNRI). It is an antidepressant and is used to treat major depressive disorder (MDD). Pristiq can cause low sodium levels as a result of a syndrome known as the syndrome of inappropriate antidiuretic hormone (SIADH). 

Although low sodium levels are not frequently reported by patients taking Pristiq, it can occur in some patients, especially older adults. If you observe the signs of low sodium while taking Pristiq you must contact your healthcare provider. 

What are the symptoms of low sodium levels?

Low sodium levels in the blood are referred to as hyponatremia. It occurs when serum sodium concentration drops below 135mEq/L. Hyponatremia arises when the body holds onto too much water, which dilutes the amount of sodium in the body (2). 

The symptoms of low sodium levels in the body include the following (2):

• headache
• altered mental status 
• fatigue
• nausea
• anorexia
• vomiting

Under severe conditions, hyponatremia could result in (1):

• hallucinations
• fainting
• seizures
• coma 

How does Pristiq affect sodium levels? 

Antidiuretic hormone (ADH) is released in the body to regulate how much water is excreted by the kidneys thus affecting urine’s concentration. SIADH is a condition in which ADH is not autoregulated and is produced excessively making the kidneys reabsorb water (2). 

As more water is retained in your body, the concentration of sodium is diluted resulting in low sodium levels or hyponatremia. Pristiq affects ADH because it increases NE concentration in the body (3). 

NE stimulates the release of ADH in the body. When NE concentration is increased, the signal to release ADH is not terminated and ADH continues to be released resulting in increased water retention and absorption (3). 

Through the effects on NE, different antidepressants like Pristiq and Celexa can lead to SIADH resulting in lower levels of sodium in your body. If you experience the symptoms of hyponatremia while taking Pristiq, contact your healthcare provider. 

What does research suggest? 

Research indicates that hyponatremia while taking Pristiq is reported in older adults. In one case report, a 57-year-old female taking Pristiq developed hyponatremia. She presented with nausea, anxiety, and confusion. Her symptoms were resolved once Pristiq was discontinued (4). 

Another study explored the occurrence of hyponatremia in elderly people caused by antidepressants. SNRIs like Pristiq were associated with SIADH and antidepressant-induced hyponatremia in older adults (5). 

Pristiq is the brand name of desvenlafaxine, an active metabolite of venlafaxine. Thus venlafaxine changes into desvenlafaxine once it enters the body. Different studies have reported the occurrence of hyponatremia while taking venlafaxine (6,7,8) indicating the potential of Pristiq to affect sodium levels. 

Who is at higher risk of Pristiq-induced hyponatremia? 

Individuals who are at higher risk of developing hyponatremia while taking Pristiq are as follows (2): 

High doses of Pristiq: 

Side effects of Pristiq depend on the dose one is taking. Pristiq is considered safe and well-tolerated at a dose of 50 mg/day. Individuals taking higher doses of Pristiq are more susceptible to developing hyponatremia as a side effect. 

Age:

The incidence of hyponatremia while taking Pristiq is usually reported in older adults. Older adults are more susceptible to hyponatremia because of several health issues, taking multiple medications, and declining kidney function. 

Concomitant use of medications: 

Different other medications can cause hyponatremia as a side effect. Taking Pristiq along with these medications exacerbates the risk of low sodium levels. These medications include

• vasopressin analogs
• thiazide diuretics
• carbamazepine analogs
• NSAIDs
• antipsychotics

Health conditions: 

Different health conditions are associated with hyponatremia. Individuals with these conditions who are taking Pristiq are more susceptible to low sodium levels. These conditions include:

• congestive heart failure
• renal disease
• kidney disease
• Addison’s disease
• hypothyroidism 
• pancreatitis
• cerebral salt-washing syndrome
• diarrhea
• vomiting

How are low sodium levels in the body managed?

The management of low sodium levels in the body depends on the severity of the condition. Your healthcare provider may consider dose reduction to resolve this side effect. If that doesn’t work, switching to alternative drugs can be considered. 

Severe cases of hyponatremia are treated with the administration of intravenous saline solution. Your healthcare provider may administer 3% sodium chloride for immediate treatment (2). 

Your healthcare provider may advise fluid restriction if you are experiencing hyponatremia while taking Pristiq. This prevents further dilution of sodium concentration in the blood and allows your body to balance the sodium level (2).

Patients who are malnourished and experiencing hyponatremia due to SIADH are advised to consume a high-protein diet. This increases the amount of solute kidneys need to eliminate so they use more water for the removal of these solutes (2). 

It is important to remember that you must contact your healthcare provider if you experience the symptoms of hyponatremia. Additionally, individuals with renal impairment and older adults must use this medication cautiously. 

What are some other side effects of Pristiq?

Pristiq can cause some side effects that commonly occur while taking this medication. These side effects are not associated with hyponatremia. Common side effects of Pristiq include (1):

• nausea
• dizziness
• sweating
• anxiety
• reduced appetite
• constipation
• difficulty sleeping 

In my perspective, Pristiq can cause low sodium levels in some individuals. This risk is increased in people taking higher doses of Pristiq, older adults, individuals with some health issues, and concomitant use of some medications. Pristiq affects the sodium levels in the body through SIADH which occurs due to increased NE concentration. Different case reports of hyponatremia in individuals taking Pristiq are present. Hyponatremia is managed by dose reduction, administering saline solution, fluid restriction, or increasing protein consumption in malnourished individuals. 

References