In patients taking phenytoin, the reduction of folic acid levels sometimes results in a macrocytic anemia. The mechanism of interaction is complex, but there are data suggesting that phenytoin induces pH changes in the gut, which affect the enterohepatic circulation of folate.

Why does phenytoin cause folic acid deficiency?

Maxwell et al proposed that folate deficiency in phenytoin users might be a result of an increase in the demand for the folate co-enzymes required either for the anti-convulsant drug hydroxylations or, for other hepatic enzymes induced by these drugs.

Does phenytoin cause vitamin deficiency?

Therefore, the above analysis has witnessed that the long-term phenytoin treatment was the cause for the deficiency of Vitamin B12 or Folate concentration of Epileptic patients.

Does folic acid interfere with Dilantin?

For example, the seizure medicines phenytoin (Dilantin, Phenytek), carbamazepine (Tegretol,Tegretol XR Carbatrol) and phenobarbital can cause a deficiency of folic acid by interfering with the way it’s absorbed.

Why is folic acid given in epilepsy?

It is especially important for all women to get enough folic acid before and during pregnancy to lessen the risk of birth defects in their child. Women taking certain seizure medicines may also be at risk for birth defects in their child, therefore being aware of the role of folic acid before conception is critical.

What are the side effects of phenytoin?

• headaches.
• feeling drowsy, sleepy or dizzy.
• feeling nervous, unsteady or shaky.
• feeling or being sick (nausea or vomiting)
• constipation.
• sore or swollen gums.
• mild skin rash.

Does valproic acid cause folate deficiency?

In addition, enzyme-inducing anticonvulsants, such as phenytoin, carbamazepine, primidone, and phenobarbital, are known to decrease folate levels, and valproic acid may interfere with folate metabolism.

What are the causes of ADR?

Factors which might increase the possibility of the occurrence of ADRs include; extremes of age, gender, multiple drugs, disease state, past history of ADR or allergy, genetic factors, large doses and many other factors.

What causes drug interactions?

A drug interaction is a reaction between two (or more) drugs or between a drug and a food, beverage, or supplement. Taking a drug while having certain medical conditions can also cause a drug interaction. For example, taking a nasal decongestant if you have high blood pressure may cause an unwanted reaction.

What causes a low Dilantin level?

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.

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Can phenytoin cause osteoporosis?

Antiepileptic Drugs Certain anticonvulsants may cause bone loss. The medications most commonly associated with osteoporosis include phenytoin, phenobarbital, carbamazepine, and primidone.

What is fetal hydantoin syndrome?

Fetal hydantoin syndrome is a characteristic pattern of mental and physical birth defects that results from maternal use of the anti-seizure (anticonvulsant) drug phenytoin (Dilantin) during pregnancy. The range and severity of associated abnormalities will vary greatly from one infant to another.

Can a folate deficiency cause seizures?

Individuals with FOLR1-related folate deficiency present with ataxia, dyskinesia, spasticity, seizures, and regression in cognitive abilities and motor skills during early childhood. Seizures commonly observed include generalized tonic-clonic, atonic, and myoclonic.

Why would a neurologist prescribe folic acid?

Folic acid supplementation reduces the risk of many types of birth defects. The offspring of women taking some AEDs are at an increased risk for birth defects associated with folic acid deficiency because their AEDs lower folic acid levels in the blood.

Is phenytoin an antifolate?

Drugs that incidentally antagonize folate Such drugs include some anticonvulsants (valproic acid, carbamazepine, phenobarbital, phenytoin, and primidone) and trimethoprim. Lamotrigine is also an anticonvulsant with known (from in vitro testing) weak anti-folate effects.

Which antiepileptic drug causes megaloblastic anemia?

Badenoch2 in 1954 was the first to suggest a causal relationship between megaloblastic anemia and anticonvulsant medication in two case reports. Diphenylhydantoin, primidone (Mysoline), and barbiturates either singly or in combination have been shown capable of inducing megaloblastic anemia.

How does phenytoin affect pregnancy?

What is Phenytoin? Phenytoin is a medication used to treat epilepsy (seizure disorder). If phenytoin is taken by the mother in the first trimester, there is approximately a 5 to 10 percent chance that the baby could be born with a combination of birth defects known as the Fetal Hydantoin Syndrome.

Does phenytoin cause bradycardia?

Phenytoin is an anticonvulsant which is also a Class IB antiarrhythmic. Its common adverse drug reactions (ADRs) include gastrointestinal symptoms, psychiatric disorders, gingival hyperplasia, and rash. Bradycardia and hypotension following intravenous (IV) phenytoin are rare ADRs.

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 are the 3 types of drug interactions?

Drug interactions can be categorised into 3 groups: Interactions of drugs with other drugs (drug-drug interactions), Drugs with food (drug-food interactions) Drug with disease condition (drug-disease interactions).

How do drug interactions affect therapeutic response to medications?

In pharmacodynamic interactions, one drug alters the sensitivity or responsiveness of tissues to another drug by having the same (agonistic) or a blocking (antagonistic) effect. These effects usually occur at the receptor level but may occur intracellularly.

What is the impact of drug interactions on drug levels and dosing?

The risk of developing an adverse drug reaction secondary to a drug–drug interaction increases significantly with the number of medications a patient is receiving. Interactions affecting drug absorption may result in changes in the rate of absorption, the extent of absorption, or a combination of both.

What is unpredictable ADR?

Idiosyncratic adverse drug reactions are a heterogeneous group of adverse effects that are not predictable from the pharmacological actions of the drug. Many of these reactions occur as a consequence of pharmacogenetic variations in drug bioactivation and drug or metabolite detoxification or clearance.

What is the difference between adverse reaction and side effect?

Adverse events are unintended pharmacologic effects that occur when a medication is administered correctly while a side effect is a secondary unwanted effect that occurs due to drug therapy.

What is triage in pharmacovigilance?

Triage refers to the process of placing a potential adverse event report into one of three categories: 1) non-serious case; 2) serious case; or 3) no case (minimum criteria for an AE case are not fulfilled).

What happens if phenytoin is low?

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 causes DILANTIN levels to increase?

What increases my risk for Dilantin toxicity? Your risk of Dilantin toxicity is higher if you are elderly. Your risk is increased if your dose is increased or you take other medicines that affect the way Dilantin works. Examples include other medicines used to treat seizures and some antibiotics.

How is phenytoin metabolized?

Phenytoin is metabolized by cytochrome P450 (P450) enzymes primarily to 5-(p-hydroxyphenyl-),5-phenylhydantoin (HPPH), which may be further metabolized to a catechol that spontaneously oxidizes to semiquinone and quinone species that covalently modify proteins.

How does Dilantin affect bones?

A new study shows young women taking phenytoin (also commonly known as Dilantin) for one year lost 2.6% of the bone density in the femoral neck — the upper part of the thigh bone near the hip joint. It’s a common and dangerous site for fractures among the elderly.

How does phenytoin decrease bone density?

Some evidence suggests that antiepileptics (including phenytoin, phenobarbital, carbamazepine, and primidone) induce the cytochrome P450 enzyme system, which results in increased clearance of vitamin D, leading to secondary hyperparathyroidism, increased bone turnover, and reduced bone density.

Do seizure medications cause osteoporosis?

Risks of developing osteoporosis Having epilepsy and taking anti-epileptic drugs (AEDs) may contribute to the risk of developing osteoporosis, but how much they contribute to this risk is not clear, and will vary from person to person.