In the elliptical orbit, the center of mass of the orbiting-orbited system is at one focus of both orbits, with nothing present at the other focus. As a planet approaches periapsis, the planet will increase in speed, or velocity.
Drugs that cause hyponatremia include: 1  Diuretics: Thiazides, bumetanide, indapamide, ethacrynic acid, furosemide. 2  Antidepressants: Selective serotonin reuptake inhibitors, tricyclic antidepressants (amitriptyline, protriptyline, desipramine), monoamine oxidase inhibitors, venlafaxine.
Common causes include medications and the syndrome of inappropriate antidiuretic hormone (SIADH) secretion. Hyponatremia can be classified according to the volume status of the patient as hypovolemic, hypervolemic, or euvolemic.