GLYCERINE, ORAL

Chemistry - A trihydric alcohol, glycerin occurs as clear, sweet-tasting, syrupy, hygroscopic liquidthat has a characteristic odor. It is miscible with water and alcohol, but not miscible in oils. Glycerinsolutions are neutral to litmus. Glycerin may also be known as glycerol.

Storage, Stability, Compatibility

Glycerin oral solution should be stored in tight containers atroom temperature; protect from freezing.

Pharmacology - GLYCERINE, ORAL

Glycerin in therapeutic oral doses increases the osmotic pressure of plasma sothat water from extracellular spaces is drawn into the blood. This can decrease intraocular pressure(IOP). The amount of decrease in IOP is dependent upon the dose of glycerin, and the cause andextent of increased IOP. Glycerin also decreases extracellular water content from other tissues andcan cause dehydration and decreased CSF pressure.

Uses, Indications

Oral glycerin is used primarily for the short-term reduction of IOP in smallanimals with acute glaucoma. It may also be considered for use to reduce increased CSF pressure.
The IOP-lowering effect of glycerin may be more variable than with mannitol, but since it may begiven orally, it may be more advantageous to use in certain cases.

Pharmacokinetics - GLYCERINE, ORAL

Glycerin is rapidly absorbed from the GI tract; peak serum levels generallyoccur within 90 minutes and maximum decreases in IOP usually occur within an hour of dosingand usually persist for up to 8 hours. Glycerin is distributed throughout the blood and is primarilymetabolized by the liver. About 10% of the drug is excreted unchanged in the urine. Serum half-lifein humans is about 30-45 minutes.

Contraindications, Precautions, Reproductive Safety

Glycerin is contraindicated in patientshypersensitive to it. It is also contraindicated in patients with anuria (well established), severelydehydrated, severely cardiac decompensated, or with frank or impending acute pulmonary edema.
Glycerin should be used with caution in animals with hypovolemia, cardiac disease, or diabetes.
Acute urinary retention should be avoided during the preoperative period.
The safety of this drug in pregnant animals is unknown; use only when potential benefits outweigh the risks of therapy.

Adverse Effects, Warnings

Vomiting after dosing is the most common adverse effect seen withglycerin use. In humans, headache, nausea, thirst and diarrhea have also been reported.

Overdosage, Acute Toxicity

No specific information was located, but cardiac arrhythmias, nonketotic hyperosmolar coma, severe dehydration have been reported with the drug.

Drug Interactions

Concomitant administration of carbonic anhydrase inhibitors (e.g., acetozolamide, dichlorphenamide) or topical miotic agents may prolong the IOP-reducing effects of glycerin.