If you think taking too much laxative isn't good for you, you're wrong. It's actually worse than what you thought - laxative overdose may kill you.

The US Food and Drug Administration (FDA) has issued a statement to warn those who use over-the-counter (OTC) laxatives to ease constipation. According to the FDA, some of these products can be dangerous if the dosage instructions or warnings on the Drug Facts label aren't properly followed.

The advice concerns laxatives with the active ingredient sodium phosphate which are recommended to be taken in a single dose only once a day and for no longer than three days. Also called saline laxatives, these products are sold under the brand name Fleet or as store brands and generic products.

According to FDA, adults older than 55 and adults and children with certain health conditions particularly those who have kidney disease, heart problems or dehydration, should seek advice from a healthcare service provider before taking these products because they have higher risks for harmful side effects. The agency said it has identified several cases of serious side effects associated with the use of OTC sodium phosphate laxatives for the treatment of constipation. Thirteen of them were fatal.

According to Mona Khurana, a medical officer in FDA's Division of Nonprescription Regulation Development and a pediatric nephrologist, the most serious harm in recent reports occurred after consumers took a single dose that was higher than what was recommended on the drug label or took more than one dose in a day.

"The bottom line is that these products are safe for otherwise healthy adults and older children for whom dosing instructions are provided on the Drug Facts label as long as they follow these dosing instructions and don't take the product more often, or in greater amounts, than the label instructs," Khurana says.

Khurana also gave advice on giving laxatives to young children. "Caregivers should not give these products orally to children under age 5 years without first asking a health care professional. Both caregivers and health care professionals should avoid the rectal use of these drug products in children under age 2 years," she said. "If you have any concerns about using the products, particularly for use with young children, talk to your health care professional first."