Vraag
Gepost op: 6 maart 2013Zetpillen met pentobarbital.
Wij hebben in de apotheek een voorschrift ontvangen voor Nembutal (=pentobarbitalnatrium) 60mg pro suppo. De bereiding op zich is geen probleem maar kan pentobarbitalnatrium wel geabsorbeerd worden in het rectum? Ik meen dat fenobarbitalnatrium niet kan geabsorbeerd worden in de darm door de lokale pH.
Antwoord
Hieronder vind je twee abstracts van publicaties over dit onderwerp.
Phenobarbital was administered to five patients, eight to 20 years of age, by four different administration routes: Intravenous, intramuscular, oral, and rectal. At each administration, extent of bioavailability, elimination rate constant, absorption rate constant, and volume of distribution of phenobarbital were calculated using a one-compartment open model. The results obtained suggest that rectal administration of phenobarbital is more reliable than intramuscular or oral administration of the drug for rapid treatment in children.
68 infants received 7--15 mg phenobarbital and sodium-phenobarbital/kg body weight by suppositories of different melting-points and hydroxyl-values (Witepsol H 12, W 35, E 76). The kinetic analysis of the serum concentration curve shows that the rate of rectal absorption is significantly increased if sodium-phenobarbital instead of phenobarbital is applied. The absorption rate is faster using suppositories with a lower melting-point (32.5 degrees C) compared to suppositories with a higher one (37.5 degrees C). Increasing the amount of hydroxyl values in the vehicle the absorption rate of phenobarbital becomes faster. Comparing the area under the serum concentration curve after intravenous and rectal application in 8 infants the absorption ratio was 74%.