Glycerin (Oral)

The relief of pressure around the eyes is one of the primary uses for glycerin, typically for patients who have com/health/coma/">glaucoma, or are about to undergo some kind of eye surgery.


The most common use of orally ingested glycerin is for relieving pressure around the eyes, which is necessary for patients who suffer from glaucoma. It is also used prior to eye surgery, when it is desirable to reduce pressure before delicate operations are performed. It is available only by prescription from a doctor, and is marketed in the U.S. under the brand name of Osmoglyn.

Acute attacks of glaucoma are managed very quickly with glycerin, and its effectiveness makes it one of the most recommended treatments for the disease because of this quality. By creating an osmotic gradient between ocular fluids and plasma, glycerin reduces intraocular pressure, providing effective relief to the sufferer.

It is not recommended for patients who are dealing with extreme dehydration, cardiac decompensation, acute pulmonary edema, or who experience any kind of hypersensitivity to any of the ingredients which it is comprised of.

Condition Treated

  • Relieve eye pressure (Glaucoma), Bowel evacuation

Type Of Medicine

  • Ophthalmic, Hyperosmotic diuretic

Side Effects

Besides the beneficial effects imparted to patients using glycerin, there may be some unwanted side effects experienced to a greater or lesser degree. While many patients will not experience any side effects whatsoever, it is possible that other patients will experience mild to moderate side effects such as those listed below. If you should have any of these side effects yourself and they are uncomfortable enough that you feel medical treatment is necessary, you should contact your doctor at the earliest opportunity.

Although it is extremely rare, it's possible that you might experience an allergic reaction to glycerin, and if this occurs, you should seek medical attention immediately, because there is a potential for these symptoms to worsen and even to become life-threatening. The symptoms most recognizable for a person having an allergic reaction to glycerin are as follows:

  • Severe itchiness in various locations around the body
  • Swelling or puffiness in the facial area, especially in the tongue, lips, and eyelids
  • Severe dizziness or lightheadedness
  • A tightness in the chest, often accompanied by severe difficulty with breathing
  • The appearance of hives and/or rashes on skin surfaces.

Other side effects associated with the ingestion of glycerin include some or all of the following:

  • Persistent headaches
  • Nausea and/or vomiting
  • Confusion or disorientation
  • Fast or irregular heartbeat
  • Diarrhea
  • Lightheadedness, with the sensation you are about to faint
  • Dry mouth and/or an increased thirst.

In addition to those listed above, other fairly mild side effects may come and go in the immediate aftermath of taking glycerin. These rarely require any kind of medical attention, and will simply subside on their own accord, as your body adjusts to the medication.


A standard dosage of glycerin for both adults and children calls for between 1 and 2 g per kilogram of weight prior to surgery, or as treatment for an acute attack of glaucoma. A standard preparation would be to mix a 50% oral solution with sodium chloride 0.9%, flavored with some kind of fruit juice such as orange, lemon, or lime.

Alternatively, a commercially premixed solution may be administered which is between 50% and 75% flavored. If necessary, this dosage may be repeated approximately every six hours as needed. While the dosage level described above is fairly typical, your precise dosing should be set by your family doctor, based on several factors such as the strength of the medication itself, elapsed time between doses, and the specific medical condition which is being treated.

If you should miss a scheduled dosage of glycerin, it is permissible to take it as soon as you remember. However, if you don't remember until near the next regularly scheduled dosage, it's better to skip the missed dose and just take the next scheduled one. It's never advisable to double up on dosages just to get back on schedule.


Before using glycerin, it's a good idea to prepare a list of all the medications you're currently using, including vitamins, herbal supplements, over-the-counter drugs, and any other prescription medications which you are currently taking. Your doctor can review this list and determine if there is any potential for drug interactions between glycerin and anything else you are using. It is possible for interactions between some drugs to take place and trigger undesirable side effects in the patient, and these can sometimes be severe enough that they warrant extreme caution and vigilance. It's also possible for interactions to occur which diminish the effectiveness of one of the drugs, in some cases rendering usage of that drug almost useless.

If you're taking any other kind of medication at all, it's a good idea to have this list on hand in case you ever have to go to an emergency room clinic or some other kind of healthcare facility where your primary care doctor is not in residence. This medication list can be extremely helpful for an emergency room doctor to be able to prescribe treatment for your condition safely, while avoiding the potential for drug interactions.

With regard to drugs known to interact with glycerin, there is only one which is commonly checked by doctors, and that is arsenic trioxide.

It's usually not a good idea to be using alcohol or tobacco at the same time that you are taking any other prescription medication, so you should consult with your doctor if you do use either alcohol or tobacco.

There are a few medical conditions which may be impacted by using glycerin:

  • Heart disease or kidney disease' there's a potential for glycerin to exacerbate any symptoms or conditions associated with these two diseases
  • Confused or disoriented mental state
  • Type II diabetes mellitus 'there is a potential for glycerin to either initiate a condition of dehydration, or to worsen a dehydrated condition that already exists.


With most prescription medications, there is a potential for medical conditions to be impacted other than the condition you are actually treating. Taking glycerin via the oral route, there are very few warnings or precautions which are associated with the drug, and for the most part, patients need not be concerned with impact to other medical conditions.

However, it advisable for patients who are suffering from type II diabetes mellitus to consult with their doctor about taking glycerin, because of the potential for worsening dehydration. There may also be some impact on patients who have a confused metal state or who have liver or kidney disease. If you have any of these existing conditions, make sure to consult with your doctor prior to taking glycerin.

Some patients who take glycerin will experience mild to moderate headaches, and if this should occur with your own usage of the drug, it can often be relieved simply by lying down for a short period after ingestion. If these headaches persist or if they become worse, you should contact your doctor for advice.

Generally speaking, your family doctor will want to consult with you regularly while you are being treated with glycerin, to ensure that the medication is being effective in treatment, and that there are no tolerance issues with your body.

There are no unusual risks regarding pediatric patients who take glycerin, and for the most part children will be subject to the same kind of side effects and precautions that older patients would be. Geriatric patients are slightly more at risk from dehydration than younger patients, since glycerin is known to reduce fluid levels in the body, and seniors generally have lower fluid levels to begin with.

There are no extensive studies or research programs which have been conducted on animal populations to suggest that there are any adverse effects on pregnant women taking glycerin. There are likewise no studies which have been conducted that suggest there are any difficulties for women who choose to breastfeed while taking glycerin. In medical literature, there are also no reports of problems with fetal development for women being treated with glycerin.

However, it is still advisable that any woman who is pregnant or thinking of becoming pregnant should discuss the situation with the family doctor prior to being treated with glycerin. Any plans to breastfeed an infant should also be a subject for consultation with the family doctor.


When storing glycerin at home, it should always be kept in a closed container, and the location should only be subject to normal room temperatures, with no extremes of hot or cold temperatures. It's also advisable to make sure there is no excess humidity in the room where your glycerin is to be stored, and direct light is also to be avoided.

All precautions should be taken to ensure that glycerin is not accessible to pets or small children, even if that means the medication has to be stored in a very high place which cannot be reached, even by standing on furniture.

If the expiration date has been exceeded, the glycerin should not be used, and should instead be discarded. However, it should not simply be flushed down the toilet or sink drain, but should be disposed of according to proper methods. If your doctor or pharmacist has not discussed proper disposal methods with you, you can look these up on the FDA website for the safe disposal of medicines.


Glycerin is a prescription medication which is most commonly used in the treatment for an acute attack of glaucoma, or as a preparatory step before eye surgery. It acts to relieve pressure around the eyes, and is therefore extremely useful in such situations. It has very few side effects or precautions which are associated with it, so most patients can use this drug with no tolerance issues whatsoever. When used orally, it can be taken as needed, although dosing should always be at six hour intervals to avoid excess usage, and precise dosing should be pre-determined by your family doctor.