Valsartan is a high blood pressure drug that is considered generally safe and tolerated better by patients than alternative treatments. Like any drug, however, valsartan comes with side effects.

Some side effects of valsartan are more serious than others and require medical attention. Possible serious side effects of valsartan include allergic reactions and rare instances of liver damage.

Less serious, but more common, valsartan side effects include headache and dizziness. The medication may also cause weight gain, and it poses serious risk to the unborn if taken during pregnancy.

Though rare, side effects of valsartan can be serious.

Valsartan carries warnings about the potential for low blood pressure. If you also take water pills and are on a low-salt diet while taking valsartan, you are most likely to develop low blood pressure.

The drug’s label warns health care providers to monitor kidney function and potassium in vulnerable patients. Valsartan has also been linked to rare instances of acute liver injury.

Valsartan is considered extremely dangerous to the unborn. Patients should not take valsartan medications when they may be pregnant. Valsartan carries a black box warning against use during pregnancy.

Patients taking valsartan have reported renal (kidney) impairment to the FDA. For patients with kidney disease, valsartan can make it worse.

Symptoms of kidney impairment include unexplained weight gain and swelling in hands, feet or ankles. Valsartan may increase the level of potassium in your blood. This risk is increased in people with heart failure and kidney problems

Valsartan may cause serious allergic reactions. If you have trouble breathing, develop hives or if your tongue or throat swells, seek immediate medical help.

In rare cases, the drug has caused angioedema, or severe swelling beneath the skin’s surface. Some patients who took valsartan and experienced angioedema had previously suffered the side effect with other drugs, including ACE inhibitors. The drug’s label advises patients not to take Diovan again if they had angioedema.

Pregnant women should not take valsartan. Valsartan can cause injury or even death to a developing fetus when taken during the second and third trimesters of pregnancy, according to a black box warning on the drug’s label.

As soon as you know you are pregnant, you should stop taking valsartan as soon as possible.

It’s not known if valsartan passes through breast milk and harms infants. Because of this, you should talk to your doctor before breastfeeding while taking valsartan.

The FDA has received reports of elevated liver enzymes and very rare reports of hepatitis in patients taking valsartan.

In clinical trials, patients treated with Diovan experienced occasional elevations of liver chemistries, according to the drug label. Three patients treated with valsartan stopped taking the drug because of elevated liver chemistries.

Before starting valsartan, tell your doctor if you have liver problems. The FDA recommends care be exercised in patients with liver disease.

The FDA has received reports of impotence among patients taking valsartan. The drug label does not specify whether that impotence refers to erectile dysfunction.

However, some studies have suggested that drugs in the same category of valsartan may actually have a beneficial effect on the sexual function of patients with high blood pressure.

One large study found that valsartan improved all aspects of sexual function, particularly erectile function. The Journal of Clinical Hypertension published the study in January 2007. It involved more than 3,500 patients.

In July 2018, the FDA announced that batches of valsartan were contaminated by a probable cancer-causing substance called N-nitrosodimethylamine, or NDMA. The agency said the drugs sold in the U.S. have been tainted for as long as four years.

People who are exposed to NDMA may suffer liver damage. NDMA exposure can also increase the risk of tumors in the liver, kidney and lungs.

Lawyers are preparing to file valsartan lawsuits on behalf of people who were diagnosed with liver damage, tumors or cancer after taking recalled valsartan medications.

Common side effects of valsartan are generally mild and brief. They don’t necessarily require patients to stop taking Diovan or a generic form of valsartan.

Weight gain is not listed on the valsartan label as a side effect. But a study of FDA reports found incidents of weight gain among valsartan patients.

Weight gain was more pronounced for women 60 and older who took the drug for between two and five years, also took the drug Lyrica and had high cholesterol. eHealthMe published the study on its website.

Hair loss is not among the side effects listed on valsartan’s label. A review of FDA reports found that out of more than 20,000 people reporting side effects while taking valsartan, 145 people reported hair loss. It’s not clear whether those people might have experienced hair loss without taking valsartan.

Coughing is a listed side effect of valsartan, but coughing is less common with valsartan than with other blood pressure medications.

Researchers have reported that coughing in valsartan patients was no more common than in patients taking a placebo.

Valsartan HCTZ is a combination of valsartan and the diuretic hydrochlorothiazide.

In addition to the potential side effects of valsartan, hydrochlorothiazide has its own potential side effects.

Among them are blurred vision, tingling in the hands, legs and feet, and potentially severe skin reactions.