Murchison L E, How J, Bewsher P D
Br J Clin Pharmacol. 1979 Dec;8(6):581-7. doi: 10.1111/j.1365-2125.1979.tb01048.x.
1 Propranolol and metoprolol were both effective in controlling the symptoms and signs of hyperthyroidism. 2 Propranolol caused a highly significant increase in serum reverse T3 concentrations with lesser changes in other serum thyroid hormone levels, whereas metoprolol did not have this effect. 3 Steady-state plasma propranolol and metoprolol levels showed marked inter-individual variation. Metoprolol concentrations showed relatively little intra-individual variability, and could be related to the clinical efficacy of the drug, whereas no such relationship was demonstrated for propranolol.