Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Captopril.

Angioedema: Angioedema (a serious allergic reaction that causes the area around the throat and tongue to swell) may occur with the use of ACE inhibitors, including captopril. This occurs for about 1 in 1,000 people. If you experience swelling of the face, tongue, or throat, stop taking captopril at once and seek immediate medical attention. People who have had angioedema caused by other substances may be at increased risk of angioedema while taking an ACE inhibitor.

Cough: People taking captopril may develop a dry, persistent cough that usually disappears only after stopping or lowering the captopril dose. Be sure to tell your doctor of any cough that does not seem to be related to a usual cause.

Fluid and electrolyte levels: Increases in blood levels of potassium occur for a small percentage of people who take captopril. This rarely causes problems, but your doctor should monitor your potassium levels. People with kidney disease or diabetes are at a higher risk of having increased blood potassium while taking captopril.

Infection: Captopril can reduce the number of cells that fight infection in the body (white blood cells). Tell your doctor immediately if you notice signs of an infection, such as fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness. Your doctor will do blood tests regularly to monitor the number of specific types of blood cells in your blood.

Report any signs of infection, such as sore throat or fever, to your doctor.

Kidney function: Changes in kidney function have been seen in certain people taking Captopril. The use of diuretics (water pills) or aliskiren may further increase the risk of kidney problems for those already at risk for this problem. If you have kidney disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Captopril, and whether any special monitoring is needed.

Let your doctor know if you notice any decrease in urine output or increased swelling of the lower limbs, which suggests an accumulation of fluid due to decreased urination.

Liver function: Changes in liver function have occurred in people with or without preexisting liver problems during treatment with this medication. In most cases, the changes were reversed when the medication was stopped. If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Low blood pressure: Occasionally, blood pressure drops too low after taking captopril. This usually happens after the first or second dose or when the dose is increased. It is more likely to occur for those who take aliskiren or water pills, have a salt-restricted diet, are on dialysis, are suffering from diarrhea or vomiting, or have been sweating excessively and not drinking enough liquids. Get up slowly when rising from a sitting or lying down position. If low blood pressure causes you to faint or feel lightheaded, contact your doctor.

Excessive sweating and lack of fluid intake may lead to an excessive fall in blood pressure because of reduced fluid in your blood vessels. Vomiting or diarrhea may also lead to a fall in blood pressure. Consult your doctor if you feel your blood pressure is too low.

Surgery: If you are scheduled to have any type of surgery, inform all the doctors involved in your care that you are taking captopril.

Pregnancy: ACE inhibitors such as captopril may cause severe harm or death to the developing baby if taken by the mother during pregnancy. Captopril should not be used during pregnancy. If you become pregnant while taking Captopril, contact your doctor immediately.

Breast-feeding: Small amounts (1%) of captopril are passed from the mother to the infant in breast milk. The effect of this amount on the breast-fed child has not been determined. Talk to your doctor about whether you should breast-feed while taking Captopril.

Children: The safety and effectiveness of using Captopril have not been established for children.