Hypertension is dubbed as “the silent killer,” mostly because most patients do not even know that they have the condition until they have complications.  In fact, it is estimated that around 30 percent of Americans, and as much as 60 percent of hospitalized patients, are struggling with hypertension in any of its forms.

If, as a nurse, you feel that you are administering way too many antihypertensive medications to your patients, it must mean that you probably are. However, the number of patients with the condition isn’t the only worrying factor; some patients can require two or more drugs to keep their hypertension at bay. This can sometimes be a real challenge, because nurses must always stay on top of the medications’ effects, side effects, and interactions. Teaching patients about these drugs is essential when helping them manage their hypertension.

In this article, you will find some of the most commonly used drugs to treat hypertension, as well as the considerations you must keep in mind when teaching your patient how to treat their condition.

Treatment Via Diuretics

In many cases, diuretics are the first type of treatment issued to patients with hypertension because they’re inexpensive, easy to use, and have relatively few side effects. Diuretics achieve their antihypertensive effects by ridding the body of excess salt and water from the body, eliminating the excess pressure exerted upon the blood vessels by these fluids.

The most common types of diuretics are the potassium-sparing loop and thiazide. Physicians often use the latter, in the form of hydrochlorothiazide, because they are easy to find and are inexpensive. However, the major adverse effects of thiazide, and diuretics in general, are the electrolyte imbalance that they create, as well as dehydration.

Patient Teaching Points

• Diuretics must be used with caution in diabetics, as they can increase serum glucose and cholesterol levels. Furthermore, patients that are taking thiazide or loop diuretics must be monitored for signs of hypokalemia in the form of muscle weakness and changes in mental status, including irritability. The same applies to patients that are taking potassium-sparing diuretics, such as triamterene or the aldosterone antagonist.
• It’s a good practice to teach patients to take their diuretics in the morning, in order to avoid frequent  urination and diuresis at night.
• Always weigh the patient at the same time every day and report any significant weight gain, such as 3 pounds in 3 days.
• Remember to teach the patient that, even if feeling well, they should never skip their medical appointments because renal function must always be monitored, especially when under treatment with diuretics.

Treatment Via Adrenergic Blockers

Adrenergic blockers affect primarily the fight-or-flight response triggered by the effect of the sympathetic nervous system hormones, which also increase blood flow to the heart, lungs, skeletal muscles, and brain.

When triggered, these hormones essentially put the heart on overdrive and may cause damage to those who are already suffering from hypertension. Certain adrenergic blockers can select the beta1 receptors in the heart, and prevent the increases in heart rate due to the effects of the hormones, sparing it from ischemia and the damaging effects of hypertrophy and remodeling.

Other adrenergic receptors, called the alpha receptors, can cause vasoconstriction of peripheral blood vessels when stimulated, which can reduce blood flow to the heart, lungs, skeletal muscles, and brain. Alpha blockers prevent these effects, resulting in vasodilation of the peripherals vessels and reduced blood pressure.

Patient Teaching Points

• For patients with certain conditions like diabetes or asthma, the use of adrenergic blockers must be carefully monitored. For the former, these medications could mask the symptoms of hypoglycemia and, for the latter, they can block the beta2 receptors in the pulmonary vasculature, resulting in the exacerbation of asthma symptoms.
• It’s important that the patient knows not to stop treatment with these drugs suddenly due to the risk of rebound tachycardia and hypertension.
• When using alpha-blockers, the patient must be kept apprised of the risks of orthostatic hypotension, which can cause falls. To this end, they must also be instructed only to take their medication before bedtime, and to always stand up slowly, to avoid dizziness.

Treatment Via Calcium Channel Blockers

Another method of controlling blood pressure is by the manipulation of the channels that deliver calcium to the heart or that affect the peripheral blood vessels, which is exactly what calcium channel blockers achieve. However, these drugs can produce certain side effects including tachycardia, bradycardia, flushing, dizziness, and headaches, as well as carry an increased risk of use in patients that are prone to angina.

Patient Teaching Points

• It’s important to teach patients to always report signs of dizziness or if they are feeling an irregular heart rate.
• Certain precautions must be taken when under treatment via calcium channel blockers, such as refraining from drinking grapefruit juice because this substance interferes with the hepatic metabolism of these drugs, leading to higher blood drug levels and increased pharmacologic effects. In the same vein, using these drugs alongside cytochrome P450 isoenzymes inhibitors, such as erythromycin, will inhibit the metabolism of amlodipine, resulting in a stronger antihypertensive effect.

Treatments With RAAS Drugs

The renin-angiotensin-aldosterone system (RAAS) is hands-down the most complex hormonal mechanism for the regulation of blood pressure control in the entire body. There are three main types of drugs that help control hypertension by acting directly on the RAAS: ACE inhibitors, angiotensin II receptor blockers (ARBs), and renin inhibitors.

The first type of drug, ACE inhibitors, intervene in the final step of angiotensin I conversion into angiotensin II, which is a very potent vasoconstrictor and stimulant for the production of aldosterone. Aldosterone, on the other hand, is a substance that increases the reabsorption of sodium and water by the kidneys. Angiotensin II promotes myocardial and vascular endothelial remodeling, which produces harmful cardiovascular effects in the long run. By taking ACE inhibitors, a person can effectively avoid these harmful side effects, and reduce their morbidity and mortality from heart failure.

The second drug, ARBs, completely block the type 1 receptors for angiotensin, preventing vasoconstriction, aldosterone and antidiuretic hormone secretion, sodium and water retention, sympathetic nervous system stimulation, and cellular growth. Meanwhile, the drug does nothing to block the type 2 receptors for angiotensin, producing beneficial effects such as vasodilation, tissue differentiation and development, and prevention of hypertrophy.

Meanwhile, renin inhibitors prevent the conversion of angiotensin I to angiotensin II, thus stopping the creation of the harmful substance in its track.

In this sense, the drugs that interfere with the RAAS help to lower blood pressure, while also producing a beneficial effects, such as inhibiting vascular hyperplasia and cardiac-muscle remodeling that occurs in response to injury from chronic hypertension and myocardial infarction.

Patient Teaching Points

• If a patient is undergoing treatment via drugs that act on the RAAS system, they must be informed not to take potassium supplements. Furthermore, if they are already taking them, they must be asked to stop, as these drugs may increase the levels of the mineral in the blood which, combined with the supplements, may produce dangerous effects.
• Some of these drugs, especially ACE inhibitors, may cause dry coughing as a side effect.
• There are several rare, but dangerous side effects that may occur from the use of these drugs such as agranulocytosis, proteinuria, glomerulonephritis, acute kidney failure, and angioedema. This last one is more common in African-Americans and smokers.

Treatment via Direct Vascular Dilators

These drugs are meant to relax the smooth muscles in the arterial walls, decreasing blood pressure. However, they don’t directly affect cardiovascular health, so they are not recommended as first-line drugs. They can, however, be successfully used for when the patient is resistant to other antihypertensive medication.

Patient Teaching Points

• Treatment via Hydralazine may trigger lupus symptoms in the patient, which disappear once the therapy with this drug is stopped.
• Treatment via minoxidil may promote hair growth in many parts of the body, including the face, which may distress certain patients, especially women. However, this irregular hair growth stops once the treatment stops.

Treatment via Central Adrenergic Agonists

These drugs directly stimulate the alpha2-adrenergic receptors in the central nervous system, which decreases blood pressure by reducing sympathetic activity. These drugs are relatively safe and recommended as first-line treatments for pregnant women.

Patient Teaching Points

• The treatment with central adrenergic agonists may lead to an increased risk of orthostatic hypotension, so patients must be instructed to always rise from a sitting to standing position with caution.
• Common side effects of these drugs include dry mouth, sedation, depression, constipation, blurred vision, and urine retention.
• There is an inherent risk of rebound hypertension if forcefully abandoning this drug, so patients must be careful not to stop treatment on their own.

As a nurse, it’s vital for you to know each drug’s effects, side effects, and interactions as well. It’s the only way to ensure the best quality of care for the patient.