Care should be taken with patients whose cardiac reserve is poor. Beta-adrenoreceptor blocking agents should be avoided in overt heart failure. However, they may be used in patients whose signs of failure have been completed. Atenolol may be used with caution in patients with chronic obstructive airways disease. However, some increase in airways resistance may occur occasionally in asthmatic patients. This can be reversed by the commonly used dosage of bronchodilators such as Salbutamol or Isoprenatine. Patients suffering from ischemic heart diseases, as with other beta-blocking agents, treatments should not be discontinued abruptly. In pregnancy and lactation, Atenolol has been used effectively under dose supervision for the treatment of pregnancy-associated hypertension. There was no evidence or fetal abnormalities. However, it is required that anticipated benefits be weighed against possible risks.