Adrenocorticotrophic action of long-acting tetracosactrin compared with corticotrophin-gel

Abstract

Location of Placenta-Thompson et al. BMTM 391At the end of the scan the individual counting rates from each detector viewing the " hot" region indicate whether the placenta was anterior or posterior. ResultsThe indications for placentography were a suspicion of placenta praevia in 58 patients who presented with antepartum haemorrhage (52) or a persistent unstable lie at 37 weeks (6) (see Table), and the need to define the placenta before amniocentesis in four. The usual gestation period at which the test was performed was 32-33 weeks, but satisfactory results were obtained as early as 30 weeks. In four patients placenta praevia diagnosed on scanning was not confirmed clinically. These false-positive results were due mainly to overcautious assessment of the scans early in the series, and with experience it has been possible to increase the accuracy of prediction. Of 42 patients with antepartum haemorrhage 32 were allowed home for intervals of two to six weeks after placentography had indicated that the placenta was in the upper uterine segment; no foetal loss resulted. Summary of Results Placental DiscussionClinical Applications.-The accuracy of the method described is 93%, and is comparable to that of other reported isotope techniques; its main clinical value is the exclusion of placenta praevia before allowing the patient home for part or all of the remainder of the antenatal period, and it is -important in this connexion to note that in no patient was a placenta praevia missed. In this way we calculate that the equivalent of three out of 100 hospital beds a year are released for other purposes. No attempt was made to estimate the degree of placenta praevia, as all cases carrv the risk of further possible severe haemorrhage, and are therefore kept in hospital until after delivery.The other application of the procedure is before amniocentesis, when there is clinical evidence of an anteriorly placed placenta. Here the scan is useful in the selection of a suitable puncture site.Choice of Isotope.-Albumin tagged with 181I was chosen as the most suitable tracer material, because it has been successfully used elsewhere for placental location (Weinberg et al., 1957; Heagy and Swartz, 1961 ; Durfee and Howieson, 1962), its biological characteristics are fully known, its production is reliable, it is relatively cheap, and it is readily obtained commercially. Isotopes such as 1321 and technetium 99m have the advantage of a much shorter half-life, so that larger quantities of radioactive material can be used, resulting in higher counting rates and better discrimination. If, however, the facilities required for routine production of albumin, tagged with these isotopes are not available 1811 albumin has been shown to give satisfactory results. SummaryA technique of isotope placental location is described which uses 1311 and a colour autoscan apparatus. The use of a twocollimator modification has been found to increase the definition of this method, so that the readily available albumin-tagged 1811 gave satisfactory re...

Long‐term Cognitive Outcomes of a Cohort of Children with Cryptogenic Infantile Spasms Treated with High‐dose Adrenocorticotropic Hormone

“…Although the precise milligram depot-tetracosactide to International Units of ACTH relation is unclear, the best estimates are that 1 mg tetracosactide is equivalent to ∼80 U to 100 U ACTH gel in terms of maximal plasma cortisol concentration (20)(21)(22). However, depot-tetracosactide has a longer duration of action; mean plasma level had returned to normal by 24 h after the corticotropin gel, and by 48 h after I mg depot-tetracosactide.…”

Comparison of the Adrenocorticotrophic Activities of Two Synthetic Polypeptides: Synacthen and DW 75

“…Introduction Martinez-Manautou et al (1966, 1967 showed that continuous dosage with 0.5 mg. of chlormadinone acetate daily exerted an antifertility effect, though ovulation was not always inhibited. In a trial involving over 900 women for more than 8,000 cycles only one pregnancy occurred that could be attri-buted to a failure of the method, giving a pregnancy rate of 0.2 per 100 woman-years.…”

Prolonged Corticotrophic Action of a Synthetic Substituted 1-18 ACTH

“…It has potent corticotrophic properties but a length of action of only four to five hours when used in an unmodified form (Landon et al, 1964). In order to produce a therapeutically useful preparation tetracosactrin has been adsorbed on to zinc phosphate to delay its absorption from the site of injection (tetracosactrin depot, Synacthen depot, Cortrosyn depot) and the adrenocorticotrophic actions of this compound last for 24 to 48 hours after an intramuscular injection of 1 mg (Besser et al, 1967;Nelson et al, 1968;Haupt et al, 1969;Treadwell and Dennis, 1969). However, this preparation may produce painful local reactions if given subcutaneously or sometimes intramuscularly (Besser et al, 1967;Nelson et al, 1968;Treadwell and Dennis, 1969), and this seems to be due to the contained zinc complexes.…”

“…In order to produce a therapeutically useful preparation tetracosactrin has been adsorbed on to zinc phosphate to delay its absorption from the site of injection (tetracosactrin depot, Synacthen depot, Cortrosyn depot) and the adrenocorticotrophic actions of this compound last for 24 to 48 hours after an intramuscular injection of 1 mg (Besser et al, 1967;Nelson et al, 1968;Haupt et al, 1969;Treadwell and Dennis, 1969). However, this preparation may produce painful local reactions if given subcutaneously or sometimes intramuscularly (Besser et al, 1967;Nelson et al, 1968;Treadwell and Dennis, 1969), and this seems to be due to the contained zinc complexes. Occasionally generalized allergic reactions after tetracosactrin depot occur though in general it can be used in patients who are hypersensitive to animal ACTH (El-Shaboury, 1968;Jensen and Sneddon, 1969).…”