From the Guidelines
For a patient who cannot take oral Tegretol, intravenous administration of an alternative antiepileptic medication such as phenytoin or fosphenytoin is recommended, as carbamazepine does not have an available IV formulation. According to the provided evidence [ 1 ], carbamazepine (Tegretol) does not have an IV formulation available, making it necessary to consider alternative medications. The study published in the Annals of Emergency Medicine [ 1 ] provides information on loading doses and routes of administration for various antiepileptic medications, including phenytoin and fosphenytoin.
Some key points to consider when choosing an alternative medication include:
- The loading dose and route of administration: Phenytoin can be loaded orally or intravenously, while fosphenytoin is available for IV administration [ 1 ].
- The potential for adverse effects: Both phenytoin and fosphenytoin can cause adverse effects, including hypotension, bradyarrhythmias, and cardiac arrest with IV phenytoin, and local irritation at the injection site with fosphenytoin [ 1 ].
- The cost and availability of the medication: Fosphenytoin is now available as a generic, which may reduce its cost [ 1 ].
It is essential to note that the choice of administration route and medication should be made on a case-by-case basis, taking into account the individual patient's needs and medical history. Once the patient can resume oral intake, they should be transitioned back to oral carbamazepine at their previous effective dose to minimize the risk of withdrawal seizures or symptom recurrence.
From the FDA Drug Label
Conversion of patients from oral Tegretol tablets to Tegretol suspension: Patients should be converted by administering the same number of mg per day in smaller, more frequent doses (i.e., twice a day tablets to three times a day suspension).
The patient who cannot take anything by mouth cannot be given Tegretol suspension or tablets. No alternative formulation is mentioned in the label for patients who cannot take oral medications. 2
From the Research
Alternatives to Oral Tegretol
When a patient cannot take anything by mouth, alternative routes of administration for their antiepileptic medication, such as Tegretol (carbamazepine), must be considered.
- Non-enteral routes of administration, including intravenous, intramuscular, sublingual, and rectal routes, can be used for various medications, including psychotropics 3.
- For patients with epilepsy who cannot take their usual oral medications, strategies such as using non-pill oral formulations, intravenous formulations of the patient's home AED(s), a benzodiazepine bridge, and/or alternative intravenous AED(s) can be employed 4.
- Specifically for carbamazepine, an intravenous formulation can be used when patients are unable to take the medication orally 4.
- It is essential to consider the pharmacokinetics of the alternative route of administration, including potential alterations in absorption and metabolism 3.