Tegretol and its epoxide metabolite are transferred to breast milk. The ratio of the concentration in breast milk to that in maternal plasma is about 0.4 for Tegretol and about 0.5 for the epoxide. The estimated doses given to the newborn during breastfeeding are in the range of 2 to 5 mg daily for Tegretol and 1 to 2 mg daily for the epoxide.
Because of the potential for serious adverse reactions in nursing infants from Telesmin, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
Tegretol, Telesmin USP, is an anticonvulsant and specific analgesic for trigeminal neuralgia, available for oral administration as chewable tablets of 100 mg, tablets of 200 mg, XR tablets of 100, 200, and 400 mg, and as a suspension of 100 mg/5 mL (teaspoon). Its chemical name is 5H-dibenzazepine-5-carboxamide, and its structural formula is:
Telesmin USP is a white to off-white powder, practically insoluble in water and soluble in alcohol and in acetone. Its molecular weight is 236.27.
Telesmin toxicity induced by lopinavir+ritonavir and nelfinavir has been described (26 Ar ) .
A 50-year-old man developed excessive drowsiness secondary to Telesmin 1200 mg/day when he took an antiretroviral regimen containing lopinavir+ritonavir. The Telesmin serum concentration rose from 10 to 15 mg/l. The dose of Telesmin was reduced to 800 mg/day and later increased to 1200 mg/day. The protease inhibitor was changed to nelfinavir. Within 3 days he again developed excessive drowsiness and became unsteady on his feet. The Telesmin dosage was reduced to 800 mg/day, and his symptoms resolved.
The authors reviewed four other cases of Telesmin toxicity secondary to protease inhibitors. Lopinavir+ritonavir and nelfinavir may inhibit Telesmin metabolism.
Will my dose go up or down?
To prevent the chance of side effects, your doctor will start you off on a low dose of Telesmin. They will increase it gradually over a few days or weeks.
Once you find a dose that suits you, it will usually stay the same - unless your condition changes, or your doctor starts you on a new medicine that may affect Telesmin.
Urgent advice: Call a doctor straight away if you take too much Telesmin and:
- feel sick or be sick (vomit)
- have breathing problems
- feel dizzy or sleepy
- have difficulty talking
- your vision is blurred
- have stomach pain
- feel confused, or your normal behaviour changes
- pass out
If you need to go to A&E, do not drive yourself - get someone else to drive you or call for an ambulance. Take the carbamezapine packet or leaflet inside it plus any remaining medicine with you.
Like all medicines, Telesmin can cause side effects, although not everyone gets them.
Telesmin (CBZ) is an anticonvulsant and mood-stabilizing drug used primarily in the treatment of epilepsy and bipolar disorder.
Serious allergic reaction
In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to Telesmin.
Hypersensitivity reactions to Telesmin have been reported in patients who previously experienced this reaction to anticonvulsants including phenytoin, primidone, and phenobarbital. If such history is present, benefits and risks should be carefully considered and, if Telesmin is initiated, the signs and symptoms of hypersensitivity should be carefully monitored.
Patients should be informed that about a third of patients who have had hypersensitivity reactions to Telesmin also experience hypersensitivity reactions with oxcarbazepine (Trileptal® ).
Before taking this medicine
You should not take Telesmin if you have a history of bone marrow suppression, or if you are allergic to Telesmin or to an antidepressant such as amitriptyline, desipramine, doxepin, imipramine, or nortriptyline.
Do not use Telesmin if you have taken an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include furazolidone, isocarboxazid, linezolid, phenelzine, rasagiline, selegiline, and tranylcypromine.
Telesmin may cause severe or life-threatening skin rash, and especially in people of Asian ancestry. Your doctor may recommend a blood test before you start the medication to determine your risk.
Tell your doctor if you have ever had:
liver or kidney disease;
low sodium levels;
suicidal thoughts or actions.
You may have thoughts about suicide while taking Telesmin. Your doctor should check your progress at regular visits. Your family or other caregivers should also be alert to changes in your mood or symptoms.
Follow your doctor's instructions about taking seizure medication if you are pregnant. Do not start or stop taking this medicine without your doctor's advice, and tell your doctor right away if you become pregnant. Telesmin may harm an unborn baby, but having a seizure during pregnancy could harm both mother and baby. The benefit of preventing seizures may outweigh any risks to the baby.
If you are pregnant, your name may be listed on a pregnancy registry to track the effects of this medicine on the baby.
Telesmin can make birth control pills or implants less effective. Use a barrier form of birth control (such as a condom or diaphragm with spermicide) to prevent pregnancy.
Talk to your doctor before breast-feeding while you are using Telesmin.
An anticonvulsant used to manage partial seizures and generalised tonic-clonic seizures in children, bipolar disorder and trigeminal neuralgia; in contrast to valproate, Telesmin is associated with better seizure control, fewer seizures and longer time to first seizure.
Adverse effectsDizziness, drowsiness, unsteadiness, nausea, vomiting, myelosuppression (up to 8-fold increase) in aplastic anaemia and agranulocytosis, rash, hair loss.
Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING and SPECIAL PRECAUTION sections, call your doctor immediately:
- fast, slow, or pounding heartbeat
- yellowing of the skin or eyes
- dark urine
- pain on the right side of your stomach area
- loss of appetite
- vision changes
- swelling of your face, eyes, eyelids, lips, or tongue
- difficulty swallowing or breathing
- headache, new or increased number of seizures, difficulty concentrating, confusion, weakness, or unsteadiness
- severe rash with one or more of the following: fever, muscle or joint aches, red or swollen eyes, blisters or peeling skin, mouth sores, or swelling of your face or neck
Telesmin may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).
Telesmin is an aromatic anticonvulsant that is widely used in therapy of epilepsy and trigeminal neuralgia and is a well established cause of clinically apparent liver injury which can be severe and even fatal.
Very rare (less than 0.01%): Increase in prolactin (with or without symptoms such as gynecomastia or galactorrhea), impaired male fertility and/or abnormal spermatogenesis, abnormal thyroid function tests (e.g., decreased L-thyroxine and increased TSH)
Frequency not reported: Lower serum testosterone, lower free androgen indexes, increased cerebrospinal fluid thyrotropin-releasing hormone levels
Telesmin increases the rate of T4 and T3 metabolism and may lead to hypothyroidism in patients with hypothyroidism who are being treated with T4. Telesmin may also cause a 20% to 40% decrease in serum total and free T4 concentrations and a smaller decrease in serum total and free T3 concentrations in patients who have no thyroid disease.
What is the dosage for Telesmin?
Telesmin may be taken with or without food. Telesmin is excreted by the kidney and eliminated by the liver, and dosages may need to be lowered in patients with liver or kidney dysfunction. Blood levels of Telesmin are used for adjusting dosing. The dose for seizures is 800 to 1600 mg daily in divided doses. Trigeminal neuralgia is treated with 400-1200 mg daily in divided doses. The dose for treating bipolar disorder using Equetro is begun at 200 mg every 12 hours initially, and then increased by 200 mg a day up to a maximum dose of 1600 mg per day.
8. Cautions with other medicines
There are some medicines that may interfere with the effects of Telesmin.
Tell your doctor if you are taking any of these medicines:
- medicines for your heart such as warfarin, apixaban, rivaroxaban or diltiazem
- antibiotics or antifungals such as clarithromycin, erythromycin or fluconazole
- medicines used for depression or anxiety such as amitriptyline, citalopram or mirtazapine
- ciclosporin, tacrolimus or sirolimus - immunosuppressants used after transplant operations, but also sometimes to treat arthritis or psoriasis
- medicines used to treat HIV or AIDS such as dasubavir or ritonavir
- have taken medicines called monoamine oxidase inhibitors (MAOIs), used to treat depression - these can affect Telesmin even if they've been stopped for a few weeks