Salbutamol

Additional information

Salbutamol is also known as albuterol in English literature. It is a β2-agonist used for short term treatment of reversible obstructive pulmonary disease such as asthma, chronic obstructive pulmonary disease (COPD). Parenteral salbutamol is sometimes used as short term treatment in pregnant women to prevent premature labor [5,6].

Pharmacokinetics and dosing

In a study on sex and race differences in salbutamol pharmacokinetics (31 men, 29 women), 8 mg oral solution was given as a single dose. The apparent volume of distribution (Vd) was higher in men than in women (631±171 vs. 510±109 L). The maximum concentration and elimination rates were lower in men (10.3±2.1 vs. 12.0±1.9 ng/ml, and 0.14±0.01 vs. 0.16±0.01/h). When corrected for ideal body weight the difference in Vd was not different between the sexes [7]. No clinically relevant differences between men and women have been found [7-10], and therefore there are no general recommendations to differentiate dosing according to sex.

Effects

In a study on the effect of salbutamol (16 men, 14 women), men had a higher increase in FEV1 after salbutamol inhalation compared to women. When corrected for predicted FEV1 no sex differences was seen. However, the men in the study had a lower predicted FEV1 at baseline compared to the women which may have confounded the results [7].

Adverse effects

No studies with a clinically relevant sex analysis regarding the adverse effects of salbutamol have been found.

Reproductive health issues

When used to prevent premature labor it has been reported that salbutamol can cause retinopathy in the premature child [11]. Regarding teratogenic aspects, please consult Janusmed Drugs and Birth Defects (in Swedish, Janusmed fosterpåverkan).

Other information

In a study on inhalation technique using metered dose inhalers (33 men, 26 women), 75% of the participants had an incorrect inhalation technique, especially women, regardless of age. Only 4% of women and 43% of men had an acceptable inhalation technique. The authors speculate that this may add to the worse asthma prognosis in women, shown in a meta-analysis of six trials of randomly assigned asthma treatment [1].

Several studies have shown worse prognosis for women with asthma. In an observational registry study (416 men, 498 women), women were found to have more asthmatic symptoms, worse quality of life and require more health care due to their asthma [2]. In a Danish prospective study on hospitalization due to asthma (6104 men of whom 2.5% had asthma, 7436 women of whom 2.2% had asthma), women had a 1.7 higher relative risk to be hospitalized [3]. An observational study from Singapore found hospitalization due to asthma to be more common in boys than girls aged 0-4 years (boys/girls ratio 1.69). In adults aged 35-64 years, women were more hospitalized (men/women ratio 0.81) [4].