Indirin Drug Interactions

Combination not recommended: Combined use of beta-blockers and calcium channel blockers with negative inotropic effects (e.g., verapamil, diltiazem) can lead to an exaggeration of the negative AV conduction and sinus node function particularly in patients with impaired ventricular function and/or SA or AV conduction abnormalities. This may result in severe hypotension and bradycardia. The combination with propranolol should be avoided, especially in patients with cardiac decompensation.
Concomitant use of sympathomimetic agents e.g., adrenaline, may counteract the effect of beta-blockers. Caution must be exercised in the parenteral administration of preparations containing adrenaline to patients taking beta-blockers as in, rare cases, vasoconstriction, hypertension and bradycardia may result.
Beta-agonist bronchodilators: Non-cardio selective beta-blockers oppose the bronchodilator effects of beta-agonist bronchodilators. Propranolol is contraindicated in patients with asthma.
Fingolimod: Potentiation of bradycardia effects with possible fatal outcomes. Treatment with Fingolimod should not be initiated in patients receiving beta-blockers. In case of combination, at least overnight monitoring is appropriate for treatment initiation.
Barbiturates: The plasma levels and the effects of beta-blockers are reduced by the barbiturates. Barbiturates are potent liver enzyme inducers which may increase the metabolism of propranolol.
Propafenone: Plasma propranolol levels can be raised up to 100% by propafenone. This probably was because propranolol is partially metabolized by the same enzyme like propafenone (CYP2D6). This combination is also not advisable because propafenone has negative inotropic effects.
Warfarin: Propranolol may cause a reduction in clearance and an increase in plasma concentrations of warfarin.
MAO inhibitors: Concomitant use of MAO inhibitors (except MAO-B inhibitors) with antihypertensive agents may diminish the antihypertensive effect and lead to hypertensive reactions.
Glycosides: Digitalis glycosides, in association with beta-blockers, may increase atrio-ventricular conduction time.
Combination to be used with caution, dose adjustment may be required: Amiodarone: A few cases suggest that patients treated with amiodarone can have severe sinus bradycardia when treated concomitantly with propranolol. Amiodarone has an extremely long half-life (about 50 days), which means that interactions may occur long after discontinuation of therapy.
Class I Antiarrhythmic drugs (Disopyramide, Quinidine): Class I antiarrhythmic drugs and beta-blockers have additive negative inotropic effects which may result in hypotension and severe hemodynamic side effects in patients with impaired left ventricular function.
Non-steroidal anti-inflammatory/anti-rheumatic drugs (NSAIDS): Anti-inflammatory drugs of NSAID-type counter the antihypertensive effect of beta-blockers. It has been studied mainly in indomethacin. In a study on diclofenac, no such interaction could be detected. Data for COX-2 inhibitors are missing.
Cimetidine: Cimetidine increases levels of propranolol in plasma, probably by inhibiting its first pass metabolism. There may be a risk of bradycardia with oral dosing.
Alcohol: Concomitant use of alcohol may increase the plasma levels of propranolol.
Anaesthetics: Concomitant use of beta-adrenergic antagonists and anaesthetics may attenuate reflex tachycardia and increase the risk of hypotension. As a general rule, avoid sudden withdrawal of beta-blocker treatment. The anaesthesiologist should be informed when the patient is receiving beta-adrenergic antagonists. Anaesthetics agents causing myocardial depression are best avoided.
Epinephrine (Adrenaline): A number of reports are available for severe hypertension and bradycardia in patients treated with propranolol and epinephrine. These clinical observations have been confirmed by studies in healthy volunteers. It has also been suggested that the intravascular administration of epinephrine may trigger these reactions.
Fluvoxamine: Fluvoxamine inhibits oxidative metabolism and increases plasma concentrations of propranolol. This may result in severe bradycardia.
Centrally-acting antihypertensives (Clonidine, Moxonidine, Methyldopa): Concomitant use of centrally acting antihypertensive drugs may worsen heart failure by a decrease in the central sympathetic tonus (reduction of heart rate and cardiac output, vasodilation). Abrupt withdrawal, particularly if prior to beta-blocker discontinuation, may increase risk of "rebound hypertension". If the two drugs are co-administered, the beta-blocker should be withdrawn several days before discontinuing clonidine. If replacing clonidine by beta blocker therapy, the introduction of beta-blockers should be delayed for several days after clonidine administration has stopped.
Rifampicin: The metabolism of propranolol may be increased by potent liver enzyme inducer rifampicin.
Alpha blockers: Concomitant use with alpha-blockers increases the risk of hypotension, especially orthostatic hypotension, and tachycardia and palpitations.
Dihydropyridine calcium channel blockers (Nifedipine): Concomitant use may increase the risk of hypotension, and cardiac failure may occur with latent cardiac insufficiency.
Chlorpromazine: The concurrent use of chlorpromazine with propranolol can result in a marked rise in plasma levels of both drugs, and thereby enhance its effects on heart rate and blood pressure as well as an enhanced antipsychotic effect for chlorpromazine and an increased antihypertensive effect for propranolol.
Lidocaine: Administration of propranolol during infusion of lidocaine may increase the plasma concentration of lidocaine by approximately 30%. Patients already receiving propranolol tend to have higher lidocaine levels than controls. The combination should be avoided.
Anti-migraine drugs: During concomitant treatment with propranolol, it inhibited the first-pass metabolism of rizatriptan whose AUC increases by 70-80%. A dose of 5 mg of rizatriptan is recommended for combination therapy. Ergotamine with propranolol has resulted in reports of vasospastic reactions in some patients.
Theophylline: Propranolol reduces the metabolic clearance of theophylline by about 30% at a dosage of 120 mg/day and 50% at doses of 720 mg/day.
Insulin and oral antidiabetic drugs: Concomitant use may mask certain symptoms of hypoglycemia (palpitations, tachycardia). Propranolol may prolong the hypoglycemic response to insulin.
Tobacco: Tobacco smoking can reduce the beneficial effects of the beta-blockers on heart rate and blood pressure.
Laboratory tests: Interfere with laboratory tests - propranolol has been reported to interfere with the estimation of serum bilirubin by the diazo method and with the determination of catecholamines by methods using fluorescence.