by Jacki Hart, MD
Q: I take a hydrochlorothiazide diuretic for high blood pressure; are there any herbs or supplements that I should avoid?
A: This is an excellent question because safety should be the first consideration when thinking about the use of herbal or dietary supplements. Safety precautions are particularly important when you are already taking one or more medications. Certain drugs and supplements may interact and produce undesirable effects.
Hydrochlorothiazide (HCTZ) is one of a group of medications known as thiazide diuretics, which are used to treat high blood pressure. These drugs act on the kidneys to increase the production of urine, and they cause the body to lose water as well as sodium and other electrolytes.
Licorice
The most worrisome interaction for thiazide diuretics is with licorice (Glycyrrhiza glabra), an herb traditionally used for stomach ulcers. Even when taken individually, this herb and this type of drug can each lower potassium levels. Low levels of potassium in the blood can have serious effects, such as muscle weakness and abnormal rhythms of the heart.Licorice can also increase blood pressure, and therefore should never be used by someone with high blood pressure, whether taking a medication to control this condition or not.
Ginkgo
There is one published report of a reaction between a thiazide diuretic and ginkgo biloba. This herb is used for Alzheimers disease as well as circulatory problems such as prevention of stroke and treatment of peripheral vascular disease. In this particular case, a person taking the thiazide diuretic with ginkgo experienced an unexpected rise in blood pressure, despite being on the diuretic to control blood pressure. It is not clear if such an interaction would occur in most people taking both a thiazide diuretic and ginkgo, but until more is known, these substances should only be taken together under the supervision of your doctor. This supervision should include frequent blood pressure measurements during the first three to six months of using them jointly.
My suspicion, however, is that many people have used ginkgo and an HCTZ diuretic together since there is an overlap among people with high blood pressure and those with circulatory problems such as heart disease and peripheral vascular disease, as well as those at risk for Alzheimers disease. Nonetheless, until research clarifies this interaction, it is essential to be carefully monitored by your doctor if you combine these substances.
Electrolytes
Since thiazide diuretics cause the body to lose water and electrolytes (salts) such as sodium, it can cause electrolyte imbalances. These include excessive losses of potassium and/or magnesium and too much retention of calcium. In fact, the risk of abnormally elevated blood levels of calcium is even greater when taking vitamin D at the same time as a thiazide diuretic. When taking this medication, doctors generally monitor electrolytes very closely because of this risk of imbalances.
It is important, therefore, to inform your doctor of any changes
Q: I take a hydrochlorothiazide diuretic for high blood pressure; are there any herbs or supplements that I should avoid?
A: This is an excellent question because safety should be the first consideration when thinking about the use of herbal or dietary supplements. Safety precautions are particularly important when you are already taking one or more medications. Certain drugs and supplements may interact and produce undesirable effects.
Hydrochlorothiazide (HCTZ) is one of a group of medications known as thiazide diuretics, which are used to treat high blood pressure. These drugs act on the kidneys to increase the production of urine, and they cause the body to lose water as well as sodium and other electrolytes.
Licorice
The most worrisome interaction for thiazide diuretics is with licorice (Glycyrrhiza glabra), an herb traditionally used for stomach ulcers. Even when taken individually, this herb and this type of drug can each lower potassium levels. Low levels of potassium in the blood can have serious effects, such as muscle weakness and abnormal rhythms of the heart.Licorice can also increase blood pressure, and therefore should never be used by someone with high blood pressure, whether taking a medication to control this condition or not.
Ginkgo
There is one published report of a reaction between a thiazide diuretic and ginkgo biloba. This herb is used for Alzheimers disease as well as circulatory problems such as prevention of stroke and treatment of peripheral vascular disease. In this particular case, a person taking the thiazide diuretic with ginkgo experienced an unexpected rise in blood pressure, despite being on the diuretic to control blood pressure. It is not clear if such an interaction would occur in most people taking both a thiazide diuretic and ginkgo, but until more is known, these substances should only be taken together under the supervision of your doctor. This supervision should include frequent blood pressure measurements during the first three to six months of using them jointly.
My suspicion, however, is that many people have used ginkgo and an HCTZ diuretic together since there is an overlap among people with high blood pressure and those with circulatory problems such as heart disease and peripheral vascular disease, as well as those at risk for Alzheimers disease. Nonetheless, until research clarifies this interaction, it is essential to be carefully monitored by your doctor if you combine these substances.
Electrolytes
Since thiazide diuretics cause the body to lose water and electrolytes (salts) such as sodium, it can cause electrolyte imbalances. These include excessive losses of potassium and/or magnesium and too much retention of calcium. In fact, the risk of abnormally elevated blood levels of calcium is even greater when taking vitamin D at the same time as a thiazide diuretic. When taking this medication, doctors generally monitor electrolytes very closely because of this risk of imbalances.
It is important, therefore, to inform your doctor of any changes