Side Effects of Apresoline (hydralazine)

Apresoline (hydralazine) is an antihypertensive medication used to treat high blood pressure (hypertension), alone or in-combination with other anti-hypertensive medications. It is also used for treating hypertensive crisis and congestive heart failure.

Apresoline is a peripheral arterial vasodilator and causes relaxation of blood vessels which carry blood away from the heart and towards the organs and tissues. The exact mechanism of how Apresoline causes arterial smooth muscle relaxation is not yet understood. Apresoline affects calcium movement within blood vessels. Calcium is required for muscle contraction and therefore disturbances in calcium movement may cause smooth muscle relaxation in the blood vessels.

Apresoline is selective for arterioles (small arteries), and the overall effects of treatment include a decrease in arterial blood pressure, and peripheral vascular resistance. In addition to treating high blood pressure, Apresoline has shown to be beneficial for the treatment of congestive heart failure (CHF).

Although ACE inhibitors are preferred for the treatment of CHF, Apresoline in combination with isosorbide dinitrate is an alternative for patients who cannot tolerate ACE inhibitors. Parenteral or injectable hydralazine is used to treat hypertensive emergencies (severally high blood pressure) during pregnancy.

Common side effects of Apresoline include

• headache,
• loss of appetite,
• nausea,
• vomiting,
• diarrhea,
• palpitations,
• rapid heartbeat, and
• chest pain (angina pectoris).

Serious side effects of Apresoline include

• constipation,
• paralytic ileus,
• low blood pressure,
• edema,
• paradoxical pressor response,
• shortness of breath,
• peripheral neuritis,
• numbness,
• tingling,
• tremors,
• muscle cramps,
• psychotic reactions,
• difficulty urinating,
• blood disorders,
• hypersensitivity reactions,
• nasal congestion,
• flushing,
• abnormal tear production, and
• conjunctivitis.

Drug interactions of Apresoline include sympathomimetics such as cocaine, dobutamine, dopamine, norepinephrine, epinephrine, metaraminol, methoxamine, phenylephrine, phenylpropanolamine, ephedra, and ephedrine because they may decrease the effectiveness of Apresoline.

Apresoline should be used in pregnancy only if the potential benefit justifies the potential risk to the fetus. It is used for treating high blood pressure during pregnancy. Apresoline is excreted in breast milk. Apresoline should be used cautiously in females who are breastfeeding if treatment is necessary.

Common side effects of hydralazine are:

• headache,
• anorexia,
• nausea,
• vomiting,
• diarrhea,
• palpitations,
• tachycardia (rapid heartbeat), and
• angina pectoris (chest pain).

Other less commonly reported side effects include:

• constipation,
• paralytic ileus,
• low blood pressure,
• edema,
• paradoxical pressor response,
• dyspnea (shortness of breath),
• peripheral neuritis,
• numbness,
• tingling,
• tremors,
• muscle cramps,
• psychotic reactions,
• difficulty urinating,
• blood disorders,
• hypersensitivity type reactions,
• nasal congestion,
• flushing,
• abnormal tear production (lacrimation) , and
• conjunctivitis.

Adverse reactions with Apresoline (hydralazine) are usually reversible when dosage is reduced. However, in some cases it may be necessary to discontinue the drug.

The following adverse reactions have been observed, but there has not been enough systematic collection of data to support an estimate of their frequency.

Common

• Headache,
• anorexia,
• nausea,
• vomiting,
• diarrhea,
• palpitations,
• tachycardia,
• angina pectoris.

Less Frequent

• Digestive: constipation, paralytic ileus.
• Cardiovascular: hypotension, paradoxical pressor response, edema.
• Respiratory: dyspnea.
• Neurologic: peripheral neuritis evidenced by paresthesia, numbness, and tingling, dizziness: tremors; muscle cramps; psychotic reactions characterized by depression, disorientation, or anxiety.
• Genitourinary: difficulty in urination.
• Hematologic: blood dyscrasias, consisting of reduction in hemoglobin and red cell count, leukopenia, agranulocytosis, purpura, lymphadenopathy; splenomegaly.
• Hypersensitive Reactions: rash, urticaria, pruritus, fever, chills, arthralgia, eosinophilia, and, rarely, hepatitis.
• Other: nasal congestion, flushing, lacrimation, conjunctivitis.

• MAO inhibitors should be used with caution in patients receiving hydralazine.
• When other potent parenteral antihypertensive drugs, such as diazoxide, are used in combination with hydralazine, patients should be continuously observed for several hours for any excessive fall in blood pressure.
• Profound hypotensive episodes may occur when diazoxide injection and Apresoline (hydralazine) are used concomitantly.