Life Cycle
The excretion Schistosome eggs in urine or feces depending on species
The hatching of the eggs leading to release of the free-swimming, ciliated larvae called miracidia
Miracidia find and penetrate the snails, which are the intermediate hosts (specific species of snails is dependent on the species of schistosoma)
Within the snails, two successive generations of sporocysts occur
Sporocyts gives rise to the infective free-swimming larvae with forked tails called cercariae, and they leave the snails to enter the water
Cercariae finds the human hosts and penetrate their skin
Upon entrance into the human hosts, cercariae lose their tails and become schistosomulae
The schistosomulae travels to the lungs and heart via the venous circulation
They migrate to the portal venous system of the liver where they mature into the adult form with two separate sexes
The adult male and female are paired together, exits the liver via portal venous system, and travel to the venous systems of the intestines or bladder (species dependent) and produce eggs
S. japonicum - superior mesenteric veins (but can also inhabit inferior mesenteric veins)
S. mansoni - inferior mesenteric veins (but can also inhabit superior mesenteric veins)
S. haematobium - vesicular and pelvic venous plexus of the bladder (occasionally rectal venules)
S. intercalatum and S. guineensis - inferior mesenteric plexus (lower portion of the bowels compared to S. mansoni)Schistosomes can live an average of 3–5 years, and the eggs can survive for more than 30 years after infection. Other hosts
Schistosomiasis is also a concern of cattle husbandry and mice. O-methyl-threonine is weakly effective in mouse schistosomiasis but is not in use.
There is no specific antidote to barbiturate overdose; treatment is supportive, generally  including the administration of intravenous saline, naloxone, thiamine, glucose, sodium bicarbonate to alkalize the urine and increase rate of excretion, and activated charcoal via nasogastric tube.Acetaminophen exerts its toxicity through the production of a toxic metabolite that can cause liver damage at doses as low as four grams. Larger doses can precipitate acute liver failure, acute kidney injury, or gastrointestinal bleeding; death has been known to occur with ingestion of ten to fifteen grams. The specific antidote to acetaminophen overdose is N-acetylcysteine. Mechanism of action
Butalbital exerts a generalized depressant effect on the central nervous system and, in very high doses, has peripheral effects. Acetaminophen has analgesic and antipyretic effects mediated by a metabolite that acts at cannabinoid receptors. Caffeine is thought to produce constriction of cerebral blood vessels and serves to counteract the sedative effect of butalbital.Butalbital has a half-life of about 35 hours. Acetaminophen has a half-life of about 1.25 to 3 hours, but may be increased by liver damage and after an overdose. Caffeine has a half-life of about 2.5 to 4.5 hours. References
External links
"Acetaminophen mixture with butalbital". Drug Information Portal. U.S. National Library of Medicine. "Acetaminophen mixture with butalbital and caffeine". Drug Information Portal. U.S. National Library of Medicine.