4 doctors agreed: Maybe not allergic: It's not unusual for pain medications such as morphine, demerol, or Dilaudid to be associated with some itching. They all can cause histamine release. This doesn't necessarily mean you are allergic to them. True allergy produces severe symptoms such as hives and trouble breathing. Sometimes Benadryl can help with itching. Or you can ask your doctor to try a different pain medication.
What is the most important electrolyte for the maintenance of osmotic pressure and volume in the extracellular fluid compartment? The most abundant positive ion or cation in the extracellular fluid  is sodium (Na+). Chloride (Cl-) is the most abundant negative ion  or anion.
Itâs simple. Extracellular fluid usually is the bodyfluid which is outside the cell. Everything except this is intracellular fluid. And the interstitial fluid is something that is present around the tissue cells of multicellular animals. So basically, the interstitial fluid is a major component of extracellular fluid. Dank!