Long-term clinical experience with atenolol--a new selective beta-1-blocker with few side-effects from the central nervous system.

During the last four years we have used a new cardioselective beta-adrenergic blocking substance, ICI 66.082 (atenolol or Tenormin), alone or in combination with other drugs for treatment of hypertension in a total of 104 patients, including 15 with a chronic obstructive lung disease. Fifty-one patients started treatment with atenolol because of side-effects--especially from the central nervous system--during previous treatment with non-selective beta-blockers, mostly propranolol (Inderal). Mean duration of treatment was 16 months (range 8--36) and mean dosage 163 mg/day. In 18 patients treatment with Tenormin was withdrawn, but only in 10 of them could this be referred to side-effects. Of the 51 patients who complained of or showed side-effects from another beta-blocker, 80% were improved after changing to Tenormin. Of the patients with side-effects from the central nervous system, 73% improved, especially those who complained of nightmares, hallucinations, insomnia or mild depression.