Metoprolol

Additional information

Pharmacokinetics and dosing

Studies in healthy volunteers have shown that after metoprolol administration, women have higher AUC and lower clearance than men [1, 2].No sex differences in pharmacokinetics of p.o. and i.v. metoprolol have been observed (9 men, 9 women) [3]. No sex differences in pharmacokinetics of metoprolol in children 6-17 years old have been observed (n=120)[4]. Based on the sex differences in pharmacokinetics of metoprolol, it is suggested that women may require lower than standard doses to avoid adverse effects. On the other hand, men may require larger doses to require therapeutic benefit [1].

Effects

According to the pharmacokinetics of metoprolol, women should have obtained higher plasma levels and the pharmacologic effects of metoprolol should have been greater. However, the concentration-effect relationship for metoprolol do not differ between men and women [1].

Coronary artery disease

One study found that metoprolol treated men had better anti-ischemic effects, measured as exercise duration and metabolic equivalents (METS), than women [5].

Heart failure

Mortality results from MERIT-HF trial in patients with heart failure with reduced ejection fraction (HFrEF) (3093 men, 898 women) showed very similar survival benefits in women and men with NYHA II-IV heart failure [6].

Hypertension

The antihypertensive effect of metoprolol in patients with mild to moderate hypertension (45 men, 116 women) was analyzed in an open and uncontrolled trial of metoprolol and was similar in men and women [7].

Myocardial infarction

A clinical study (4353 men, 1121 women) found no sex differences of the metoprolol effect (200 mg once daily) on post-infarction mortality [8].

Adverse effects

In an open uncontrolled trial of metoprolol in mild to moderate hypertension (45 men, 116 women), the incidence of side effects increased with age but was not influenced by the patient’s sex [7].

Reproductive health issues

Regarding teratogenic aspects, please consult Janusmed Drugs and Birth Defects (in Swedish, Janusmed fosterpåverkan).