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Emergency treatment of high blood pressure
In a hospital setting, injectable drugs may be used for the emergency treatment of hypertension. The most commonly used agents in this situation are sodium nitroprusside (Nipride, Isoket) and labetalol (Normodyne). As already mentioned, emergency medical therapy may be needed for patients with severe (malignant) hypertension. In addition, emergency treatment of hypertension may be necessary in patients with short duration (acute) congestive heart failure LVF, dissecting aneurysm (dilation or widening) of the aorta, stroke, and toxemia of pregnancy (see below). In emergency, sublingual medication with capotopril ACE inhibitor, or sublingual drops of Nefedipine are also used.
Treatment during pregnancy
Women with hypertension may become pregnant. These patients have an increased risk of developing preeclampsia or eclampsia (toxemia) of pregnancy. These conditions usually develop during the last three months (trimester) of pregnancy. In preeclampsia, which can occur with or without pre-existing hypertension, affected women have 3 things, hypertension, protein loss in the urine (proteinuria), and swelling (edema). In eclampsia (toxemia), convulsions also occur and the hypertension may require prompt treatment. The foremost goal of treating the high blood pressure in toxemia is to keep the diastolic pressure below 105 mm Hg in order to prevent a brain hemorrhage in the mother.
Hypertension that develops before the 20th week of pregnancy almost always is due to pre-existing hypertension and not toxemia. High blood pressure that occurs only during pregnancy, called gestational hypertension, may start late in the pregnancy. These women, however, do not have proteinuria, edema, or convulsions. Furthermore, gestational hypertension appears to have no ill effects on the mother or the fetus. This form of hypertension resolves shortly after delivery, although it may recur with subsequent pregnancies.
The use of medications for hypertension during pregnancy is controversial. The key question is, "At what level should the blood pressure be maintained?" For one thing, the risk of untreated mild to moderate hypertension to the fetus or mother during the relatively brief period of pregnancy probably is not very large. Furthermore, lowering the blood pressure too much can interfere with the flow of blood to the placenta and thereby impair fetal growth. So, some sort of a compromise must be met. Accordingly, not all mild or moderate hypertension during pregnancy needs to be treated with medication. If it is treated, however, the blood pressure should be reduced slowly and not to very low levels, perhaps not below 140/80.
The anti-hypertensive agents used during pregnancy need to be safe for normal fetal development. The beta-blockers, hydralazine (an old vasodilator), labetalol, alpha methyldopa (Aldomet), and more recently, the calcium channel blockers have been advocated as suitable medications for hypertension during pregnancy. Certain other anti-hypertensive medications, however, are not recommended (they are contraindicated) during pregnancy. These include the ACE inhibitors, the ARB drugs, and probably the diuretics. ACE inhibitors may aggravate a diminished blood supply to the uterus (uterine ischemia) and cause kidney dysfunction in the fetus. The ARB drugs may even lead to death of the fetus. Diuretics can cause depletion of the blood volume and so impair placental blood flow and fetal growth
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