Carbamazepine rectal
| Carbamazepine rectal | |
| What is it? | Analgesic—acting on neuropathic pain |
| Mechanism of action | Antiepileptic sodium channel blocker |
| Starting dose | 125 mg two times per day |
| Time to onset of effect | 4–8 hours17 |
| Formulation | Suppository (125 mg rectally is approximately equivalent to 100 mg PO) |
| Indication | Neuropathic pain Seizures |
| Common adverse effects | Dizziness; drowsiness; dry mouth; eosinophilia; fatigue; fluid imbalance; gastrointestinal discomfort; headache; hyponatraemia; leucopenia; movement disorders; nausea; oedema; skin reactions; thrombocytopenia; vision disorders; vomiting; weight increased16 |
| Contraindications | Acute porphyrias; AV conduction abnormalities (unless paced); history of bone marrow depression; cardiac disease; history of haematological reactions to other drugs may exacerbate absence and myoclonic seizures; skin reactions; susceptibility to angle-closure glaucoma16 |
| Caution | Hepatic impairment Bone marrow suppression |
| Licence | Licensed product for seizure control; ‘off label’ for neuropathic pain |
| Benefits | Licensed product |
| Risks | Expensive Lack of familiarity with this use in palliative care |
| Cost | £120 for 5×125 mg suppositories |
AV - atrial ventricular