What is the Difference Between Phenytoin and Phenytoin Sodium

The key difference between phenytoin and phenytoin sodium is that phenytoin is less water-soluble, whereas phenytoin sodium is highly water-soluble.

Phenytoin is useful as an anti-seizure medication. Phenytoin sodium is the sodium salt of phenytoin. Both these compounds share similar chemical and physical properties. However, they have different solubility in water.

1. Overview and Key Difference
2. What is Phenytoin
3. What is Phenytoin Sodium
4. Similarities – Phenytoin and Phenytoin Sodium
5. Phenytoin vs Phenytoin Sodium in Tabular Form
6. Summary – Phenytoin vs Phenytoin Sodium

What is Phenytoin?

Phenytoin is a medication that is useful as an anti-seizure medicine. It is abbreviated as PHT. The brand name of this compound is Dilantin. This medication is useful for the prevention of tonic-clonic seizures as well as focal seizures. However, it cannot prevent absence seizures. The drug class to which this drug belongs is known as an anticonvulsant drug class.

The routes of administration for phenytoin medication include oral administration and intravenous injection. The bioavailability of this drug in our body is about 70-100% when taken orally. The protein binding ability of this drug is about 95%. The metabolism of this drug occurs in the liver. The elimination half-life of phenytoin is 10-22 hours. Moreover, the duration of the action of this drug is about 24 hours. Excretion occurs through the urinary tract or bile.

There can be some mild side effects of phenytoin; nausea, stomach pain, loss of appetite, poor coordination, increased hair growth, and enlargement of the gums. However, there can be some serious side effects as well, which include sleepiness, self-harm, liver problems, bone marrow suppression, low blood pressure, etc.

What is Phenytoin Sodium?

Phenytoin sodium is the sodium salt of the phenytoin compound. It is a derivative of phenytoin and, it is often the active compound in phenytoin medication. Therefore, this substance is also important as an anti-seizure medication that is useful in preventing tonic-clonic seizures and focal seizures. The common route of administration for phenytoin sodium is oral administration.

Since phenytoin sodium is the sodium derivative of the phenytoin compound, the chemical and physical properties of the two compounds are mostly similar to each other. However, phenytoin sodium is soluble in water because it has a sodium cation. It is insoluble in ether and chloroform. In comparison, phenytoin (without sodium) is less water-soluble.

What are the Similarities Between Phenytoin and Phenytoin Sodium?

Phenytoin and Phenytoin Sodium are medication important as an anti-seizure medicine that is useful in preventing tonic-clonic seizures and focal seizures
They are organic compounds.
Both are soluble in water but insoluble in ether and chloroform.

What is the Difference Between Phenytoin and Phenytoin Sodium?

Both phenytoin and phenytoin sodium tends to share similar chemical and physical properties. However, they have different solubility in water. The key difference between phenytoin and phenytoin sodium is that phenytoin is less water-soluble, whereas phenytoin sodium is highly water-soluble. Phenytoin is a non-ionized chemical compound, while phenytoin sodium is an ionized chemical compound with a sodium cation.

Below is a summary of the difference between phenytoin and phenytoin sodium in tabular form for side by side comparison.

Summary – Phenytoin vs Phenytoin Sodium

Phenytoin is a medication that is useful as an anti-seizure medication. Phenytoin sodium is the sodium salt of phenytoin. The key difference between phenytoin and phenytoin sodium is that phenytoin is less water-soluble, whereas phenytoin sodium is highly water-soluble.

Reference:

1. “Phenytoin Sodium Extended Oral: Uses, Side Effects, Interactions, Pictures, Warnings & Dosing.” WebMD, WebMD.
2. “Phenytoin.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine.
3. “Solubility of Sodium Phenytoin in Ethanol + Water Mixtures at Various Temperatures.” Taylor & Francis.
4. Carmichael, Ronald R., et al. “Solubility and Stability of Phenytoin Sodium When Mixed with Intravenous Solutions.” American Journal of Health-System Pharmacy, vol. 37, no. 1, 1980, pp. 95–98., https://doi.org/10.1093/ajhp/37.1.95.

Image Courtesy:

1. “Phenytoin structure” By Harbin – Own work (Public Domain) via Commons Wikimedia
2. “Assorted Medications (33931804863)” By NIAID – Assorted Medication (CC BY 2.0) via Commons Wikimedia