Cytra-3 Oral Syrup and Phenytoin Chewable Tablets
Determining the interaction of Cytra-3 Oral Syrup and Phenytoin Chewable Tablets and the possibility of their joint administration.
In the database of official manuals used in the service creation an interaction registered by statistical results of studies was found, which can either lead to negative consequences for the patient health or strengthen a mutual positive effect. A doctor should be consulted to address the issue of joint drug administration.
Consumer:Using sodium citrate together with phenytoin may decrease the effects of phenytoin. Separate the times of administration of sodium citrate and phenytoin by at least two to three hours. If your doctor does prescribe these medications together, you may need a dose adjustment or special test to safely use both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
Professional:ADJUST DOSING INTERVAL: Concurrent administration of antacids may decrease the bioavailability of phenytoin. The mechanism of interaction is unknown. In eight healthy volunteers, coadministration of a single 600 mg dose of phenytoin and an antacid containing either aluminum-magnesium hydroxide or calcium carbonate (dose equal to 160 mEq of neutralizing capacity) given one and three hours after meals and at bedtime on the same day resulted in an approximately 25% reduction in the total area under the concentration-time curve (AUC) of phenytoin compared to administration alone. An antacid containing aluminum hydroxide-magnesium trisilicate given in an equivalent dose also reduced the AUC of phenytoin, but the difference was not statistically significant. In another study, aluminum hydroxide-magnesium trisilicate caused a 12% reduction in steady-state serum phenytoin levels in six epileptic patients, but seizure frequency was not affected. There have also been isolated case reports of patients with low serum phenytoin levels or inadequate seizure control attributed to concurrent antacid administration. In a few of the patients, serum phenytoin levels rose two to threefold when antacid administration was delayed by 2 to 3 hours. However, some studies have failed to find a significant interaction with these antacids.
MANAGEMENT: Given the narrow therapeutic index and the large interindividual variability in the pharmacokinetics of phenytoin, patients requiring concomitant antacid therapy should consider separating the times of administration by at least two to three hours if possible. Serum phenytoin levels and seizure activity should be monitored.
- "Product Information. Dilantin (phenytoin)." Parke-Davis, Morris Plains, NJ.
- Carter BL, Garnett WR, Pellock JM, et al "Effects of antacids on phenytoin bioavailability." Ther Drug Monit 3 (1981): 333-40
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- Chapron DJ, Kramer PA, Mariano SL, Hohnadel DC "Effect of calcium and antacids on phenytoin bioavailability." Arch Neurol 36 (1979): 436-8
- D'Arcy PF, McElnay JC "Drug-antacid interactions: assessment of clinical importance." Drug Intell Clin Pharm 21 (1987): 607-17
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Generic Name: citric acid / potassium citrate / sodium citrate
Brand name: Cytra-3, Polycitra, Polycitra-LC, Tricitrates, Virtrate-3
Synonyms: Cytra-3
Generic Name: phenytoin
Brand name: Dilantin, Phenytek, Dilantin Infatabs, Phenytoin Sodium, Prompt
Synonyms: Phenytoin
In the course of checking the drug compatibility and interactions, data from the following reference sources was used: Drugs.com, Rxlist.com, Webmd.com, Medscape.com.
- Cytra-3 Oral Syrup-Phenytoin Extended-Release Capsules
- Cytra-3 Oral Syrup-Phenytoin Infatabs
- Cytra-3 Oral Syrup-Phenytoin injection
- Cytra-3 Oral Syrup-Phenytoin Intravenous
- Cytra-3 Oral Syrup-Phenytoin Oral Suspension
- Cytra-3 Oral Syrup-Phenytoin Sodium
- Phenytoin Chewable Tablets-Cytra-K
- Phenytoin Chewable Tablets-Cytra-K (Potassium Citrate and Citric Acid Powder Pack)
- Phenytoin Chewable Tablets-Cytra-K (Potassium Citrate and Citric Acid Solution)