“I've been taking Tegretol for epilepsy for years, and now the psychiatrist wants to give me another medication.” Tegretol is not a new drug, but it interacts with other medications more than most, which is why it is worth understanding well. This guide explains what it is used for, what monitoring it needs, and why every doctor you see should know you are taking it.
What is Tegretol?
Tegretol is a brand name for carbamazepine. In Egypt it is available as regular tablets and as extended-release tablets sold as Tegretol CR. It is an established, long-standing psychiatric and neurological medication. It works by calming sodium channels in nerve cells, which reduces the excess electrical signaling behind epileptic seizures and helps stabilize mood.
Uses of Tegretol
- Epilepsy: partial seizures, generalized tonic-clonic seizures, and mixed seizure types.
- Trigeminal neuralgia (also called tic douloureux), a sharp, shock-like pain in the face.
- Mood stabilizer in bipolar disorder: for manic and mixed episodes, especially when lithium and valproate have not worked or are not tolerated, as part of bipolar disorder treatment.
Tegretol is not helpful for absence seizures or some other types of epilepsy, and it may make them worse. It is therefore chosen only after a careful diagnosis of the seizure type.
Side Effects of Tegretol on the Body
| System | Possible effect |
|---|---|
| Brain | Dizziness, drowsiness, unsteadiness, and blurred or double vision, especially at the start |
| Digestive system | Nausea, vomiting and dry mouth |
| Skin | Rash, and rarely serious reactions such as Stevens-Johnson syndrome |
| Immune system | Rarely, a serious drop in white blood cells, red blood cells and platelets |
| Hormones | Low blood sodium caused by excess antidiuretic hormone |
| Liver | Raised liver enzymes, and rarely hepatitis |
Boxed warnings: skin and blood
According to MedlinePlus, the risk of severe skin reactions is higher in people of Asian ancestry who carry a specific genetic factor, the HLA-B*1502 gene, so testing for it is recommended before starting treatment in people from these backgrounds. These reactions usually appear in the first few months of treatment. In rare cases carbamazepine can also reduce the production of blood cells, so the doctor orders a complete blood count before starting and at regular intervals.
- Complete blood count before treatment and periodically.
- Liver function tests.
- Sodium level, especially in older adults and people taking diuretics.
- Blood level of the drug when needed to adjust the dose.
Tegretol Interactions With Other Medications
Carbamazepine is a strong inducer of liver enzymes, so it speeds up the breakdown of many medications and weakens their effect. These include hormonal birth control pills, blood thinners such as warfarin, antipsychotics such as Seroquel and Risperdal, some antidepressants, and Lamictal. This matters especially for people being treated for addiction, because it can lower the level of methadone and buprenorphine and bring on withdrawal symptoms. Conversely, grapefruit and some antibiotics and antifungals raise its level.
Because Tegretol also speeds up the breakdown of itself after the first few weeks, the doctor may need to review the dose and measure the drug level some time after starting. So do not assume that the dose that suited you at the start will always remain right.
Pregnancy and breastfeeding
Carbamazepine is linked to a risk of birth defects if taken during pregnancy, but stopping it suddenly can cause dangerous seizures for both mother and baby. For this reason, pregnancy should be planned in advance with the doctor, and the medication should not be stopped without medical advice. During breastfeeding, the doctor decides whether to continue.
Is Tegretol addictive?
No. Tegretol does not cause addiction or a “high.” However, stopping it suddenly can cause seizures, sometimes dangerous repeated seizures, and a return of mood episodes. It is therefore withdrawn gradually under a medical plan. Do not start or stop Tegretol without a doctor.
When should you see the doctor?
Tell every doctor you see that you are taking Tegretol, especially if you are starting a psychiatric medication or addiction treatment. At Eradah Hospital, drug interactions are reviewed before any plan, within dual diagnosis programs and medically supervised detox, and the patient is followed with the necessary tests.