Propranolol was first introduced as a blood pressure drug 50 years ago and about 40 years ago it was discovered to be effective for the prevention of migraines. This is quite a remarkable drug because it is also used for rapid heart beat, heart attacks, tremor, and performance anxiety. Public speakers, musicians, and others take a small dose before performances and the drug reduces the physical stress responses such as sweating, tremulousness, weakness, and other. Blinded studies showed that musicians perform better when given a beta blocker compared to musicians who are given a placebo pill.
Since the introduction of propranolol, another two dozen beta blockers have been developed. The newer, so called selective beta blockers (they attach to only one type of stress receptor) tend to have fewer side effects than propranolol and other non-selective beta blockers. Selective beta blockers can be given to patients with well-controlled asthma, while non-selective ones can cause an asthma attack.
Recent studies have shown that chronic stress promotes the growth and spread of cancers. Researchers at MD Anderson Cancer Center decided to review the records of 1,425 patients who were treated for ovarian cancer at four hospitals between 2000 and 2010. Of these, 268 had been treated with a beta blocker while receiving chemotherapy for their ovarian cancer. The average survival of those who were on a beta blocker was 48 months compared to 42 months for those who were not. A more dramatic difference was found between those who were taking a non-selective beta blocker (propranolol in almost all cases): they lived 95 months – twice as long as women not on a beta blocker.
Considering these findings, if I decide to prescribe a beta blocker, I may start prescribing propranolol as the first-line drug for the prevention of migraines. And only if the patient has side effects, will I switch them to a selective beta blocker, such as atenolol or nebivolol (Bystolic). Common side effects of beta blockers are fatigue and dizziness from a drop in blood pressure and difficulty exercising because the heart rate cannot increase high enough to provide for the increase in demand for oxygen. Because regular aerobic exercise is my first recommendation for the prevention of migraines, I tend to reserve beta blockers for patients whose blood pressure is high or at the high end of normal range, whose pulse is fast, and for those who fail other preventive drugs and Botox (however, most insurers approve Botox for chronic migraines only if the patient fails 2 or 3 preventive drugs, including a beta blocker).
