What is phenytoin level test?
What is phenytoin level test?
The phenytoin test is ordered to measure and monitor the amount of phenytoin in the blood and to determine whether drug concentrations are in the therapeutic range. It may be ordered every few days when a patient first begins taking phenytoin to help adjust the dose to the desired blood level.
When should phenytoin levels be taken?
A level can be taken 2-4 hours following an IV loading or top-up dose (12-24 hours for oral doses) and levels should then be monitored every 24 hours until control is achieved and concentration has stabilised.
Why are phenytoin levels checked?
Phenytoin blood testing is ordered because phenytoin blood levels must be maintained within a narrow therapeutic range. If levels are too low, the affected person may experience seizures; if they are too high, the person may experience symptoms associated with phenytoin toxicity.
What happens if you take too much phenytoin?
An overdose of phenytoin can be fatal. Overdose symptoms may include twitching eye movements, slurred speech, loss of balance, tremor, muscle stiffness or weakness, nausea, vomiting, feeling light-headed, fainting, and slow or shallow breathing. Avoid drinking alcohol while you are taking phenytoin.
What does phenytoin do to the brain?
Phenytoin works by slowing down impulses in the brain that cause seizures. Phenytoin is used to control seizures. It does not treat all types of seizures, and your doctor will determine if it is the right medicine for you.
Is phenytoin a high risk medication?
Phenytoin has been linked to an increased risk of problems for your unborn baby. You’ll usually only be advised to take it if your doctor thinks the benefits of the medicine outweigh the risks. It’s important that you and your baby stay well during pregnancy.
What should I check before giving phenytoin?
Prior to the administration, the patency of the IV catheter should be tested with a flush of sterile saline. Each injection of parenteral Dilantin should then be followed by a flush of sterile saline through the same catheter to avoid local venous irritation due to the alkalinity of the solution.
How do you check phenytoin levels?
Laboratories often report the value in g/L instead (g/dL = g/L x 0.1). After a patient has received a loading dose of intravenous phenytoin, levels can be checked one hour after the dose. If loading is achieved by oral dosing, phenytoin levels can be checked 24 hours after the last dose10.
What causes low phenytoin levels?
Drugs which may decrease phenytoin levels include: carbamazepine, chronic alcohol abuse, reserpine, and sucralfate. Moban® brand of molindone hydrochloride contains calcium ions which interfere with the absorption of phenytoin.
How often should phenytoin blood levels be checked?
Phenytoin levels should be checked at specific times. Testing should be done a week to 10 days after treatment has started. Levels should be tested at regular intervals of at least once a month to ensure consistency.
What are appropriate phenytoin levels?
The normal therapeutic range for adults, who are consuming phenytoin is between 10.0-20.0 mcg/mL. As long as the drug remains within this range, there will be no side effects or other symptoms.
What does phenytoin mean?
Definition of phenytoin. : a crystalline anticonvulsant compound C 15H 12N 2O 2 used in the form of its sodium salt in the treatment of epilepsy. — called also diphenylhydantoin.