Exacerbation of panic disorder during propranolol therapy.

Two patients experienced new onset or worsening of panic disorder during treatment with propranolol for tachycardia or palpitations associated with a diagnosis of mitral valve prolapse. Both patients had a family history of panic disorder; one also had a family history of mitral valve prolapse and depression. As antidepressant drugs can treat both depression and panic disorder, it would not be inconsistent that propranolol might exacerbate either disorder. Other possible interpretations of these two cases are discussed.