A fixed-dose combination (FDC) of a benzodiazepine (Clonazepam) and a non-selective beta-adrenergic blocker (Propranolol). This combination is primarily used in the Indian context for the management of anxiety disorders, particularly where somatic symptoms like palpitations and tremors are prominent. It leverages the anxiolytic and sedative effects of Clonazepam with the beta-blocking action of Propranolol to control peripheral autonomic symptoms. Its use as an FDC is controversial and has been scrutinized by regulatory bodies for rationality.
Adult: Usually 1 tablet (Clonazepam 0.25mg + Propranolol 20mg) twice daily. May be increased gradually based on response and tolerability. Maximum: Typically 2 tablets twice daily (Clonazepam 1mg + Propranolol 80mg/day). Treatment should be at the lowest effective dose for the shortest duration.
Note: Take with or just after food to minimize gastric upset and to slow absorption, potentially reducing dizziness. Swallow whole with a glass of water. Do not crush or chew. Avoid grapefruit juice. Do not stop abruptly; taper dose gradually under medical supervision.
The combination exerts a dual mechanism: 1) Central action: Clonazepam potentiates GABAergic inhibition in the CNS (limbic system, thalamus, hypothalamus), producing anxiolytic, sedative, and anticonvulsant effects. 2) Peripheral action: Propranolol competitively blocks beta-1 and beta-2 adrenergic receptors, reducing sympathetic drive. This decreases heart rate, myocardial contractility, blood pressure, and tremor, thereby alleviating the physical symptoms of anxiety.
Pregnancy: Category D (US FDA). Both drugs cross the placenta. Clonazepam is associated with risk of fetal malformations (cleft lip/palate), neonatal flaccidity, and withdrawal symptoms. Propranolol may cause intrauterine growth restriction, neonatal bradycardia, and hypoglycemia. Use only if potential benefit justifies the fetal risk. Avoid especially in first trimester and near term.
Driving: STRONGLY DISCOURAGED. Causes drowsiness, dizziness, blurred vision, and impaired judgment and motor coordination. Patients should not drive or operate machinery until individual response is known.
| Other CNS Depressants (Alcohol, Opioids, Barbiturates, other Benzodiazepines) | Potentiated sedation, respiratory depression, risk of death | Major |
| CYP3A4 Inhibitors (Ketoconazole, Itraconazole, Clarithromycin, Ritonavir) | Increased Clonazepam levels, risk of toxicity | Major |
| CYP2D6 Inhibitors (Fluoxetine, Paroxetine, Quinidine) | Increased Propranolol levels, exaggerated bradycardia/hypotension | Moderate |
| Calcium Channel Blockers (Verapamil, Diltiazem) | Additive negative inotropic and chronotropic effects; severe bradycardia/heart block | Major |
| Digoxin | Additive bradycardia | Moderate |
| Clonidine | Potentiated hypotension; dangerous rebound hypertension if clonidine withdrawn while on propranolol | Major |
| NSAIDs (e.g., Ibuprofen, Indomethacin) | Antagonize antihypertensive effect of propranolol | Moderate |
| Theophylline | Mutual inhibition of effects; reduced bronchodilation | Moderate |
| Insulin/Oral Hypoglycemics | Propranolol masks tachycardia of hypoglycemia; may impair glucose recovery | Major |
| Levodopa | Increased risk of hypotension | Moderate |
Same composition (Clonazepam (0.25mg) + Propranolol (20mg)), different brands: