Propranolol therapy in thyrotoxicosis. A review of 84 patients undergoing surgery.

The effect of propranolol on the surgical course of 84 thyrotoxic patients undergoing partial thyroidectomy or extrathyroidal surgery was evaluated. Seventy-two patients (group 1) underwent surgery with propranolol as their sole preparatory medication, whereas in 12 (group 2) surgery was carried out after a rather prolonged period of thionamide preparation with the addition of propranolol preoperatively as an adjunctive therapeutic agent. Preoperative pulse rate and systolic blood pressure levels fell in both groups, and the clinical features of thyrotoxicosis were rapidly ameliorated with an average dose of propranolol of 330 mg (range 40 to 1,280 mg) daily. Maximal clinical response occurred within 48 to 72 hours of starting propranolol therapy. In 14 patients in group 1, paired serum calcium levels were reduced by the administration of propranolol preoperatively; serum thyroxine levels were unchanged. Serum thyroxine decay, evaluated postoperatively in the patients in group 1, was decreased. The half life of thyroxine was inversely related to the initial thyroxine levels. Analysis of these data indicates that the administration of propranolol alone provides rapid, safe and effective preparation of thyrotoxic patients for emergency or for elective thyroidal or extrathyroidal surgical procedures.

Metabolic effects of propranolol in thyrotoxicosis. I. Nitrogen, calcium, and hydroxyproline.

The effect of propranolol on the hypermetabolism of thyrotoxicosis was investigated in eight subjects with diffuse toxic goiter. After equilibration on a constant nitrogen, calcium, and hydroxproline intake, nitrogen balance was determined before and during propranolol therapy prior to subtotal thyroidectomy and compared to similar data obtained in seven of the patients following surgically induced euthyroidism. Propranolol administration was associated with clinical amelioration and a rapid, statistically significant, improvement in nitrogen retention. A slight additional improvement in retention was noted in the postoperative euthyroid state. Oxygen consumption, measured serially in four patients, was not significantly changed by propranolol. Urinary loss of calcium, phosphorus, and hydroxyproline was unaffected by propranolol, but excretion of these substances was sharply reduced in the subjects restudied postoperatively. These data offer a evidence of a previously unreported nitrogen sparing effect of oral propranolol during its short-term administration in thyrotoxic man.

Effectiveness of a new calcium antagonist in severe hypertension.

Nitrendipine is a new nifedipine-like calcium antagonist antihypertensive agent. In this study, nitrendipine 5-40 mg orally bid was administered for up to three months to 16 patients with severe essential hypertension (untreated supine diastolic blood pressure greater than or equal to 115 mm Hg). Hydrochlorothiazide or propranolol or both were also given to patients who did not achieve goal blood pressure with nitrendipine alone. Five patients achieved goal blood pressure (supine less than or equal to 90 mm Hg) with nitrendipine alone and six more after the addition of a second drug, and only four required triple-drug therapy. One patient was terminated from the study because of headaches, a common nitrendipine side effect. This study demonstrates that nitrendipine is an effective and well-tolerated agent in the treatment of severe hypertension.