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 this medication.
Breathing conditions: In general, people who have asthma and certain other breathing problems or chronic lung disease should not take a beta-blocker such as atenolol. Low doses of atenolol may be taken with caution by those with asthma who do not respond to or cannot tolerate alternative treatment.
Drowsiness/reduced alertness: The use of atenolol is unlikely to impair your ability to drive or operate machinery. However, it should be taken into account that dizziness, fatigue, or a slower reaction time may occur.
History of heart failure: If you have a history of heart failure you should be cautious while taking atenolol as it may increase the risks associated with this condition.
Hyperthyroidism:If you have hyperthyroidism (high levels of thyroid hormones) you should use caution while taking atenolol as it may reduce the symptoms of this condition, giving a false impression of improvement. Stopping the medication suddenly could worsen this condition.
Kidney disease: If you have kidney disease you should use caution while taking atenolol as you are at increased risk of experiencing side effects.
Low blood sugar: The signs of low blood sugar may not be as noticeable when taking atenolol. If you have diabetes and take insulin or other medications that affect insulin levels in the blood, you should be cautious and monitor blood sugar carefully while taking this medication.
Prinzmetal's angina: Atenolol may increase the number and duration of angina attacks in patients with Prinzmetal's angina. Therefore, people who have this condition should be cautious while taking atenolol.
Severe allergies: If you have allergies severe enough to cause anaphylaxis (a severe allergic reaction where swelling of the face, lips, and throat make it difficult to breathe), you should talk to your doctor about what to do if you have an allergic reaction. Atenolol may make it more difficult to treat your allergic reaction with epinephrine.
Slow heart rate: In general, people with an abnormally slow pulse should not take a beta-blocker such as atenolol.
Stopping usage: Atenolol should not be stopped suddenly. There have been reports of severe worsening of angina and of heart attack or abnormal heart rhythms occurring in people with angina pectoris who have done this.
Surgery: If you are scheduled for surgery, inform all doctors involved in your care that you are taking atenolol.
Pregnancy: There have not been adequate studies on the use of atenolol by pregnant women; however, studies have shown that atenolol does cross the placenta. This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: This medication passes into breast milk. If you are a breast-feeding mother and are taking atenolol, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
Children: The safety and effectiveness of using this medication have not been established for children.