V2 receptors maintain plasma osmolality and are coupled to aquaporin channels in the collecting ducts of kidneys where they regulate AVP levels. Conivaptan hydrochloride functions by antagonizing V2 receptors in the renal collecting ducts and thus causing aquaresis or water secretion. Typical pharmacodynamic effects of the drug are an increase in  net fluid loss, increase in  urine output, and decrease in the osmolality of urine. Conivaptan inhibits its own metabolism in the body, displaying non-linear pharmacokinetics. About 99% of conivaptan found is bound to human plasma proteins over the range of 10 ng/mL to 1000 ng/mL. The mean half-life of the drug is 5 hours and mean clearance is 15.2 L/hr. Adverse effects
Most adverse reactions to conivaptan are found at the site of infusion. Other complications include blood and lymphatic system disorders, gastrointestinal disorders, metabolism and nutrition disorders, psychiatric disorders as well as vascular disorders. There is risk of too rapid correction of hyponatremia causing fatal osmotic demyelination syndrome. Chemistry
Conivaptan hydrochloride is an off-white or a pale yellow power with a solubility of 0.25 mg/mL in water at 23 °C. The injectable formulation consists of 20 mg conivaptan hydrochloride, 0.4 g ethanol, 1.2 g propylene glycol and water. Development and commercialization
Conivaptan hydrochloride was discovered by Yamanouchi Pharmaceuticals and marketed by Astellas. Yamanouchi Pharmaceuticals filed a new drug application to the FDA for conivaptan hydrochloride to treat hyponatremia on 2 February 2004. On 1 December, Yamanouchi received approval for investigational hyponatremia treatment using conivaptan hydrochloride.
If the hearing loss is severe to profound in both ears, the child may be a candidate for a cochlear implant (beyond the scope of this discussion). Unilateral sensorineural hearing loss was not generally considered a serious disability by the medical establishment before the nineties; it was thought that the afflicted person was able to adjust to it from birth. In general, there are exceptional advantages to gain from an intervention to enable hearing in the microtic ear, especially in bilateral microtia. Children with untreated unilateral sensorineural hearing loss are more likely to have to repeat a grade in school and/or need supplemental services (e.g., FM system – see below) than their peers.Children with unilateral sensorineural hearing loss often require years of speech therapy in order to learn how to enunciate and understand spoken language. What is truly unclear, and the subject of an ongoing research study, is the effect of unilateral conductive hearing loss (in children with unilateral aural atresia) on scholastic performance. If atresia surgery or some form of amplification is not used, special steps should be taken to ensure that the child is accessing and understanding all of the verbal information presented in school settings. Recommendations for improving a childs hearing in the academic setting include preferential seating in class, an FM system (the teacher wears a microphone, and the sound is transmitted to a speaker at the childs desk or to an ear bud or hearing aid the child wears), a bone-anchored hearing aid (BAHA), or conventional hearing aids.