Distribution
The distribution half-life of drospirenone is about 1.6 to 2 hours. The apparent volume of distribution of drospirenone is approximately 4 L/kg. The plasma protein binding of drospirenone is 95 to 97%. It is bound to albumin and 3 to 5% circulates freely or unbound. Drospirenone has no affinity for sex hormone-binding globulin (SHBG) or corticosteroid-binding globulin (CBG), and hence is not bound by these plasma proteins in the circulation. Metabolism
The metabolism of drospirenone is extensive. It is metabolized into the acid form of drospirenone by opening of its lactone ring. The medication is also metabolized by reduction of its double bond between the C4 and C5 positions and subsequent sulfation. The two major metabolites of drospirenone are drospirenone acid and 4,5-dihydrodrospirenone 3-sulfate, and are both formed independently of the cytochrome P450 system. Neither of these metabolites are known to be pharmacologically active. Drospirenone also undergoes oxidative metabolism by CYP3A4. Elimination
Drospirenone is excreted in urine and feces, with slightly more excreted in feces than in urine. Only trace amounts of unchanged drospirenone can be found in urine and feces. At least 20 different metabolites can be identified in urine and feces. Drospirenone and its metabolites are excreted in urine about 38% as glucuronide conjugates, 47% as sulfate conjugates, and less than 10% in unconjugated form. In feces, excretion is about 17% glucuronide conjugates, 20% sulfate conjugates, and 33% unconjugated.The elimination half-life of drospirenone is between 25 and 33 hours. The half-life of drospirenone is unchanged with repeated administration.
The effect of ephedrine is delayed and the improvement occurs over a period of months.Salbutamol, a selective β(2)-adrenergic receptor agonist, has been found, in adults, to have fewer side effects than Ephedrine and to be more easily obtained in some countries. It has been trialed in children with positive resultsAs of 2022, the standard of care for DOK7  CMS is either ephedrine or salbutamol. People
Two brothers with apparent myasthenic syndrome with a seemingly circadian off/on cycle, living near Quetta, Pakistan were nicknamed the solar kids, because their condition resulted in an inability to move from approximately sunset to sunrise, while their daytime motor abilities were seemingly normal. Doctors observed that some "factor" seemed to become exhausted in the course of normal diurnal activities, and was "recharged" over the period of inertia and sleep. The father first sought help from spiritual healers, then turned to Western medicine. A younger brother of the two had also begun to manifest the same symptoms. The family had other children, two daughters and one son, who were unaffected. The "solar kids" condition, despite extensive testing, was said to be undiagnosed as of 2016, and assumed to be genetic, as their parents were cousins. Samples of their genetic material were to be sent to the UK for analysis. See also
Congenital disorder
Myasthenia gravis
Lambert-Eaton syndrome

References
External links
Congenital Myasthenic Syndromes
About Congenital Myasthenic Syndrome From the Mayo Clinic
Treatment for Congenital Myasthenic Syndromes From the Mayo Clinic