Structural Biochemistry/Diprivan

Brief History

Many have heard of Milk of Magnesia, which is a milky-white product used as an antacid to offset discomforts caused by excess acidity in the stomach. But how many have heard about Milk of Amnesia? This is the term used by some to describe the intravenous anesthetic known as propofol, or Diprivan.

The Company Behind the Drug

The manufacturer of the drug is AstraZeneca. This company was founded as a result of the union of the Swedish Astra AB with British Zeneca Group PLC. The new joint company began on April 6, 1999. The two companies wanted to combine their efforts into one company so that they would be able to make greater strides in their research and development as a biopharmaceutical company.

About the Drug

Propofol is a liquid drug that is administered into patients’ veins. It is a general anesthetic that works to start and maintain anesthesia by slowing down the activity in the brain and nervous system. It is commonly used to sedate patients who have been ventilated or those who are about to go into surgery. Dosage can vary depending on the desired affect and age of the patient. Older patients over the age of 55 receive a 20 mg dose initially and then maintained on a 0.05-0.1 mg/kg/min IV. In contrast, younger patients under the age of 55 receive a 40 mg dose initially and then maintained on a 0.1-0.2 mg/kg/min IV. Propofol is also used in pediatrics and patients in intensive care units, with dosing adjusted accordingly.

Medical uses

Propofol is used for induction and maintenance of anesthesia, having largely replaced sodium thiopental for this indication. Propofol is also used to sedate individuals who are receiving mechanical ventilation. In critically ill patients propofol has been found to be superior to lorazepam both in effectiveness as well as overall cost. Propofol is also used for procedural sedation, for example during endoscopic procedures. Its use in these settings results in a faster recovery compared to midazolam.

Drug Usage

Any individual who are allergic to any ingredient in this medication or allergic to eggs, egg products, soybeans, or soy products should avoid using this medication.

Some medical conditions may interact with this medication. An individual should tell their doctor if any medical conditions apply to them:

• taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• pregnant, planning to become pregnant, or are currently breast-feeding
• have inflammation of the pancreas, high lipid levels in the blood, or epilepsy

Note: Medicines such as Benzodiazepines, narcotic pain relievers, or other sedatives can interact with this medicine and may increase the risk of this medication's side effects.

Advantages

Propofol is fast-acting and short-lived, which means that patients would be able to get back to their daily routine and diet much sooner. Other drugs would force patients to take more time to fully recover before they get back to their baseline activities. Another advantage is that propofol can serve as an alternative to opioids. Opioids work by binding to one of three receptor sites in the body found in the central and peripheral nervous systems. Opioids share the effect of sedation but usually come with side effects such as nausea and vomiting. By replacing the use of opioids with propofol, physicians are reducing these side effects seen in patients.

Disadvantages

Despite the many advantages of propofol, it is also important to look at the disadvantages of the drug. Unlike drugs such as morphine or midalozam, Diprivan does not have something to reverse its effects. Any and all drugs effects must be lived out until the drug is fully metabolized and excreted from the body through urine. As with many drugs, patients react differently to different drugs. Some medicines work as expected in fewer than half of the people who take them because slight differences in their genes can change the way their bodies react to the drugs. More specifically, slight differences in the genes that make cytochrome P450 proteins are the culprit since these are the proteins that process many of the medications. This has sparked interest in creating “personalized medicines” that tailor to specific individuals. Until then, propofol still poses risks such as causing a patient who is breathing normally to go into full respiratory arrest without any warning signs.

Administration

It is essential to maintain a clean environment at the injection site to prevent the risk of bacterial infection. According to RxList, Diprivan contains a small amount of disodium edetate in order to help avert the growth of tiny organisms such as bacteria. It is also for this reason that Diprivan comes in single-use packaging in order to prevent open vials of the drug from nesting these microorganisms. Scientific studies have shown that contamination of the drug has lead to fevers, infections, and even death.Diprivan is usually administered in one of three ways: syringe, infusion, and volumetric pump.

syringe

According to dictionary definitions, a syringe is “a tube fitted with a hollow needle for injecting or withdrawing fluids.” This method of administering the drug is self-explanatory.

infusion

Infusion pumps infuse medication such as Diprivan into a patient intravenously. These are commonly seen in hospitals in patient rooms where there is a fluid back hanging on a pole that drips the IV fluids into the patient at a rate determined by the physician to ensure proper dosages and effect.

volumetric pumps

Volumetric pumps are a similar method of administration like infusion except for that fact that they are usually used by physicians for long-term-care patients who need the drug or fluid to be infused into their system for an extended amount of time.

References

"Diprivan." RxList. N.p., 25 Oct. 2010. Web. 20 Nov. 2012. <http://www.rxlist.com/diprivan-drug.htm>.

"Diprivan (Propofol) ." AstraZeneca. N.p., n.d. Web. 20 Nov. 2012. <http://www.astrazeneca.com/Medicines/Neuroscience/Product/Diprivan>.

Euliano, T. Y., and J. S. Gravenstein. "A brief pharmacology related to anesthesia." Essential Anesthesia: From Science to Practice. Cambridge, UK: Cambridge University Press, 2004. 173. Print.

"History." AstraZeneca. N.p., n.d. Web. 20 Nov. 2012. <http://www.astrazeneca.com/About-Us/History>.

"Propofol Sedation: Who Should Administer?." Institute for Safe Medication Practices. N.p., 3 Nov. 2005. Web. 20 Nov. 2012. <http://www.ismp.org/newsletters/acutecare/articles/20051103.asp>.

"The New Genetics." National Institute of General Medical Sciences 7.662 (2006): 64. National Institutes of Health. Web. 20 Nov. 2012.