In vitro, the Nalonee® preparation of naloxone caused a concentration-dependent relaxation of human pial cortical arteries contracted by potassium, noradrenaline, serotonin, prostaglandin F2α (PGF2α), and haemorrhagic cerebrospinal fluid, or inhibited contractions elicited by these agents. However, the preservatives in the Nalonee preparation, methyl- and propylparaben, had similar effects. Pure naloxone alone had no effect on potassium or PGF2α-induced contractions. It is suggested that the relaxant effects on vascular smooth muscle of Nalonee can be attributed to the alkylparabens rather than to naloxone. The pronounced relaxations induced by the alkylparabens had a rapid onset, and they were stable and could easily be cleared after rinsing.
ArtruAASteenPAMichenfelderJD, (1980) Cerebral metabolic effects of naloxone administered with anaesthetic and sub-anaesthetic concentrations of halothane in the dog. Anaesthesiology52:217–220
2.
BaskinDSHosobuchiY, (1981): Naloxone reversal of ischaemic neurological deficits in man. Lancet2:272–275
3.
BrandtLAnderssonK-EEdvinssonLLjunggrenB, (1981a) Effects of extracellular calcium and of calcium antagonists on the contractile responses of isolated human pial and mesenteric arteries. J Cereb Blood Flow Metabol1:339–347
4.
BrandtLLjunggrenBAnderssonK-AHindfeltBUskiT, (1981b) Effects of indomethacin and prostacyclin on isolated human pial arteries contracted by CSF from patients with aneurysmal SAH. J Neurosurg55:877–883
5.
FadenAIJacobsTPHoladayJW, (1980) Naloxone improves blood pressure and neurological recovery following cervical spinal trauma. Neurology30:433
6.
FlowerRJ, (1974) Drugs which inhibit prostaglandin biosynthesis. Pharmacol Rev26:33–67
7.
LevitanHBarkerJL, (1972) Salicylate: A structure-activity study of its effects on membrane permeability. Science176:1423–1425
8.
YoungWFlammESDemopoulusHBTomasulaJJDeCrescitoW, (1981) Effect of naloxone on post-traumatic ischaemia in experimental spinal contusion. J Neurosurg55:209–219
