|Systematic (IUPAC) name|
|Pregnancy cat.||B3 (AU) C (US)|
|Legal status||Prescription Only (S4) (AU) POM (UK) ℞-only (US)|
|Bioavailability||almost complete (~80%)|
|Mol. mass||364.417 g/mol|
|(what is this?)|
Bumetanide (trade names Bumex or Burinex) is a loop diuretic of the sulfamyl category to treat heart failure. It is often used in people in whom high doses of furosemide are ineffective. It is marketed by Hoffmann-La Roche. The main difference between the two substances is in bioavailability and pharmacodynamic potency. Furosemide is incompletely absorbed in the intestine (60%), and there is substantial inter- and intraindividual differences in bioavailability (range 10-90%). Bumetanide is almost completely absorbed (80%), and the absorption is not altered when it is taken with food. It is said to be a more predictable diuretic, meaning that the predictable absorption is reflected in a more predictable effect.
Bumetanide is 40 times more potent than furosemide (for patients with normal renal function).
In the brain, bumetanide blocks the NKCC1 cation-chloride co-transporter, and thus decreases internal chloride concentration in neurons. In turn, this concentration change makes the action of GABA more hyperpolarizing, which may be useful for treatment of neonatal seizures, that quite often are not responsive to traditional GABA-targeted treatment, such as barbiturates. Bumetanide is therefore currently under evaluation as a prospective antiepileptic drug.