Atenolol
Atenolol is a beta blocker. MedlinePlus states it is used to treat high blood pressure, angina and to improve survival after a heart attack, working by relaxing blood vessels and slowing the heart rate. Tenormin supplies atenolol alone as a tablet, while Tenoretic pairs it with the diuretic chlorthalidone.
Key points
- Atenolol’s DailyMed label describes it as a beta1-selective (cardioselective) beta-adrenergic blocker without membrane-stabilising or intrinsic sympathomimetic activity.
- Oral atenolol has an elimination half-life of approximately 6 to 7 hours.
- The atenolol and chlorthalidone label lists sensitivity to sulfonamide-derived drugs as a contraindication for Tenoretic, alongside the cardiac contraindications atenolol carries alone.
A boxed warning against stopping atenolol suddenly
One DailyMed record for atenolol tablets carries a boxed warning built around a single limb: cessation of therapy. It states that patients with coronary artery disease who are being treated with atenolol should be advised against abrupt discontinuation, because severe exacerbation of angina, myocardial infarction and ventricular arrhythmias have been reported in angina patients who stopped a beta blocker abruptly. Tenormin’s own FDA label and the atenolol and chlorthalidone label above carry the same caution as an ordinary warning, not a boxed one; the boxed status belongs to this particular label revision, not to atenolol as a whole.
Atenolol also carries a pregnancy warning, stated in full but never inside a box on the labels reviewed here. It can cause fetal harm when given to a pregnant woman, crosses the placental barrier and, from the second trimester on, has been associated with infants born small for gestational age. Beta blockers including atenolol can also mask tachycardia, an early warning sign of hypoglycaemia, though other signs such as dizziness and sweating may still appear.
Atenolol is also known regionally as Tensotin, a UAE-manufactured atenolol brand named in the Emirates Drug Establishment product directory.
Further reading
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