As of 2015, coconut water has no serious, known side effects when taken as a drink, but it may interfere with blood pressure levels when consumed after surgery, as stated by WebMD. Its blood pressure-lowering effects can also increase the potency of medications in individuals with high blood pressure.
Patients should stop consuming coconut water a minimum of two weeks prior to a scheduled surgery, and they should speak with a doctor before drinking it while taking medications for high blood pressure, as recommended by WebMD. Those who are pregnant or breast-feeding should avoid coconut water due to a lack of research concerning its safety during these periods.
Drinking too much coconut water over a short period can lead to excessive levels of potassium in the blood, which can cause life-threatening heart rhythm changes, states the Natural Health Advisory Institute. Researchers are still unsure how much potassium one can consume before experiencing dangerous side effects.
Coconut water, the liquid found inside immature coconuts, is used to treat high blood pressure and dehydration resulting from diarrhea or exercise, according to WebMD. It is a good source of potassium, magnesium and other electrolytes as well as carbohydrates. When taking coconut water for high blood pressure, patients should consume approximately 300 milliliters twice per day.