Allopurinol interactions

Capecitabine: Avoid concomitant use. (Allopurinol label, Drug interactions)

Serious Adverse Reactions with Concomitant Theophylline Serious and fatal reactions have been reported in patients receiving concurrent administration of ciprofloxacin and theophylline. (Ciprofloxacin label, Warnings and precautions)

Avoid the use of Exjade with CYP1A2 substrate theophylline. (Deferasirox label, Drug interactions)

…hormones Diuretics Cardiac glycosides, such as digitalis glycosides Quinidine Drugs potentiating hypokalemic effects of epinephrine • Potassium depleting diuretics • Corticosteroids • Theophylline Epinephrine should not be used to counteract circulatory collapse or hypotension caused by phenothiazines, as a reversal of the pressor effects of epinephrine may result… (Epinephrine label, Drug interactions)

WARNING: CARDIOVASCULAR DEATH Gout patients with established cardiovascular (CV) disease treated with ULORIC had a higher rate of CV death compared to those treated with allopurinol in a CV outcomes study [see Warnings and Precautions (5.1) ] . (Febuxostat label, Boxed warning)

Theophylline or Aminophylline : Do not co-administer with KETALAR as concomitant use may lower the seizure threshold ( 7.1 ). (Ketamine label, Drug interactions)

Quinine Prevention or Management: Avoid concomitant use Decrease AUC by 75%–85% Telithromycin Decrease AUC by 86% Theophylline Decrease exposure by 20% to 40% Effect of Other Drugs on Rifampin Concomitant antacid administration may reduce the absorption of rifampin. (Rifampin label, Drug interactions)

Phosphodiesterase Inhibitors Concomitant administration of Adempas with specific PDE-5 inhibitors (such as sildenafil, tadalafil, or vardenafil) or nonspecific PDE-5 inhibitors (such as dipyridamole or theophylline) is contraindicated [see Dosage and Administration (2.6), Drug Interactions ( 7.1 ) and Clinical Pharmacology ( 12.2 )]. (Riociguat label, Contraindications)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

Sympathomimetics, Methylxanthines, Steroids In clinical studies, concurrent administration of aclidinium bromide and other drugs commonly used in the treatment of COPD including sympathomimetics (short-acting beta 2 agonists), methylxanthines, and oral and inhaled steroids showed no increases in adverse drug reactions. (Aclidinium label, Drug interactions)

Upon initiation or discontinuation of Adalimumab-fkjp in patients being treated with CYP450 substrates with a narrow therapeutic index, monitoring of the effect (e.g., warfarin) or drug concentration (e.g., cyclosporine or theophylline) is recommended and the individual dose of the drug product may be adjusted as needed. (Adalimumab label, Drug interactions)

Theophylline: Albendazole induces cytochrome P450 1A in human hepatoma cells; therefore, it is recommended that plasma concentrations of theophylline be monitored during and after treatment. (Albendazole label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Concomitant use of the following drugs may also increase the risk of skin rash, which may be severe: bendamustine, ampicillin and amoxicillin [ see Drug Interactions (7.1) ]. (Allopurinol label, Warnings and precautions)

Concomitant use of the following drugs may also increase the risk of skin rash, which may be severe: bendamustine, ampicillin and amoxicillin [ see Drug Interactions (7.1) ]. (Allopurinol label, Warnings and precautions)

Concomitant use of the following drugs may also increase the risk of skin rash, which may be severe: bendamustine, ampicillin and amoxicillin [ see Drug Interactions (7.1) ]. (Allopurinol label, Warnings and precautions)

Dicumarol Clinical Impact Allopurinol tablets prolongs the half-life of the anticoagulant, dicumarol. (Allopurinol label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Concomitant use with allopurinol increases the exposure of either mercaptopurine or azathioprine which may increase the risk of myelosuppression. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

…also increase the risk of seizure: concomitant use of other medications that lower the seizure threshold (e.g., other bupropion products, antipsychotics, tricyclic antidepressants, theophylline, and systemic corticosteroids), metabolic disorders (e.g., hypoglycemia, hyponatremia, severe hepatic impairment, and hypoxia), or use of illicit drugs (e.g., cocaine)… (Bupropion label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

There was a small decrease in the clearance of oral cetirizine hydrochloride caused by a 400-mg dose of theophylline; it is possible that larger theophylline doses could have a greater effect [see Clinical Pharmacology ( 12.3 )]. (Cetirizine label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

Xanthine Derivatives: Theophylline Use With Caution Theophylline: Clarithromycin use in patients who are receiving theophylline may be associated with an increase of serum theophylline concentrations [see Pharmacokinetics ( 12.3 )] . (Clarithromycin label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

In order to prevent gout flares when treatment with allopurinol tablets is initiated, concurrent prophylactic treatment with colchicine or an anti-inflammatory agent is recommended [ see Dosage and Administration (2.2) ]. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Cyclosporine Clinical Impact Concomitant use of allopurinol increases cyclosporine concentrations, which may increase the risk of adverse reactions. (Allopurinol label, Drug interactions)

Dicumarol Clinical Impact Allopurinol tablets prolongs the half-life of the anticoagulant, dicumarol. (Allopurinol label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

…studies, administration of a hormonal contraceptive containing EE did not lead to any increase or only to a weak increase in plasma concentrations of CYP3A4 substrates (e.g., midazolam) while plasma concentrations of CYP2C19 substrates (e.g., omeprazole and voriconazole) and CYP1A2 substrates (e.g., theophylline and tizanidine) can have a weak or moderate increase. (Drospirenone and ethinyl estradiol label, Drug interactions)

Therefore, an increase in the metabolism of CYP1A2 substrates (e.g., theophylline, caffeine) resulting from induction is not anticipated, although clinical studies of induction have not been performed. (Duloxetine label, Drug interactions)

Tamsulosin Dosage adjustments are not necessary when tamsulosin is administered concomitantly with digoxin or theophylline [see Clinical Pharmacology (12.3) ]. (Dutasteride and tamsulosin label, Drug interactions)

Dicumarol Clinical Impact Allopurinol tablets prolongs the half-life of the anticoagulant, dicumarol. (Allopurinol label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Dicumarol Clinical Impact Allopurinol tablets prolongs the half-life of the anticoagulant, dicumarol. (Allopurinol label, Drug interactions)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

Drug Interactions Theophylline Erythromycin use in patients who are receiving high doses of theophylline may be associated with an increase in serum theophylline levels and potential theophylline toxicity. (Erythromycin label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

(See CLINICAL PHARMACOLOGY: Drug Interaction Studies .) Theophylline Fluconazole increases the serum concentrations of theophylline. (Fluconazole label, Drug interactions)

Theophylline: Clearance decreased; reduce theophylline dose by one-third ( 5.8 ). (Fluvoxamine label, Warnings and precautions)

Dicumarol Clinical Impact Allopurinol tablets prolongs the half-life of the anticoagulant, dicumarol. (Allopurinol label, Drug interactions)

• Xanthine derivatives, steroids, diuretics, or non-potassium sparing diuretics may potentiate hypokalemia or ECG changes. (Formoterol label, Drug interactions)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Dicumarol Clinical Impact Allopurinol tablets prolongs the half-life of the anticoagulant, dicumarol. (Allopurinol label, Drug interactions)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

Upon initiation or discontinuation of RENFLEXIS in patients being treated with CYP450 substrates with a narrow therapeutic index, monitoring of the effect (e.g., warfarin) or drug concentration (e.g., cyclosporine or theophylline) is recommended and the individual dose of the drug product may be adjusted as needed. (Infliximab label, Drug interactions)

Theophylline A recent study has shown that concomitant administration of isoniazid and theophylline may cause elevated plasma levels of theophylline, and in some instances a slight decrease in the elimination of isoniazid. (Isoniazid label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Theophylline Clinical Impact: Increased clearance of theophylline [see Clinical Pharmacology (12.3) ] . (Lansoprazole label, Drug interactions)

In patients taking ARAVA, exposure of drugs metabolized by CYP1A2 (e.g., alosetron, duloxetine, theophylline, tizanidine) may be reduced. (Leflunomide label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

There was a small decrease (~16%) in the clearance of cetirizine caused by a 400 mg dose of theophylline. (Levocetirizine label, Drug interactions)

However, concomitant administration of other fluoroquinolones with theophylline has resulted in prolonged elimination half-life, elevated serum theophylline levels, and a subsequent increase in the risk of theophylline-related adverse reactions in the patient population. (Levofloxacin label, Drug interactions)

Concomitant use with ethinyl estradiol-containing CHCs may increase systemic exposure of other drugs (e.g., cyclosporine, prednisolone, theophylline, tizanidine, and voriconazole). (Levonorgestrel and ethinyl estradiol label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Theophylline: Theophylline clearance may decrease when hyperthyroid patients on a stable theophylline regimen become euthyroid; a reduced dose of theophylline may be needed. (Methimazole label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Effect of XATMEP on Other Drugs Theophylline Methotrexate may decrease the clearance of theophylline. (Methotrexate label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

…may cause hypoglycemia concomitant administration of medications that may lower the seizure threshold, including other bupropion products, antipsychotics, tricyclic antidepressants, theophylline, systemic steroids Recommendations for Reducing the Risk of Seizure: Clinical experience with bupropion suggests that the risk of seizure may be minimized by adhering to… (Naltrexone and bupropion label, Warnings and precautions)

Effects of Combined Oral Contraceptives on Other Drugs COCs containing EE may inhibit the metabolism of other compounds (e.g., cyclosporine, prednisolone, theophylline, tizanidine, and voriconazole) and increase their plasma concentrations. (Norgestimate and ethinyl estradiol label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

This may result in a prolonged half-life for some drugs that are also metabolized by this system (e.g., cyclosporine, theophylline/methylxanthines, warfarin) when coadministered with quinolones. (Ofloxacin label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Theophylline Increased plasma concentrations of theophylline The theophylline dosage of may need to be decreased. (Paroxetine label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Theophylline: Theophylline clearance may decrease when hyperthyroid patients on a stable theophylline regimen become euthyroid; a reduced dose of theophylline may be needed. (Propylthiouracil label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Bronchodilator: theophylline ↓ theophylline Increased dosage of theophylline may be required; therapeutic monitoring should be considered. (Ritonavir label, Drug interactions)

Dicumarol Clinical Impact Allopurinol tablets prolongs the half-life of the anticoagulant, dicumarol. (Allopurinol label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

Drug Interactions Some studies have shown that simultaneous sucralfate administration in healthy volunteers reduced the extent of absorption (bioavailability) of single doses of the following: cimetidine, digoxin, fluoroquinolone antibiotics, ketoconazole, l-thyroxine, phenytoin, quinidine, ranitidine, tetracycline, and theophylline. (Sucralfate label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

When tadalafil was administered to subjects taking theophylline, a small augmentation (3 beats per minute) of the increase in heart rate associated with theophylline was observed. (Tadalafil label, Drug interactions)

Digoxin and Theophylline Dosage adjustments are not necessary when a tamsulosin hydrochloride capsule is administered concomitantly with digoxin or theophylline [see Clinical Pharmacology ( 12.3 )] . (Tamsulosin label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

The influence of terbinafine on the pharmacokinetics of fluconazole, cotrimoxazole (trimethoprim and sulfamethoxazole), zidovudine or theophylline was not considered to be clinically significant. (Terbinafine label, Drug interactions)

In patients taking AUBAGIO, exposure of drugs metabolized by CYP1A2 (e.g., alosetron, duloxetine, theophylline, tizanidine) may be reduced. (Teriflunomide label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Theophylline Clinical Impact Concomitant use of allopurinol doses greater than or equal to 600 mg/day may decrease the clearance of theophylline Intervention Monitor and adjust theophylline doses as reflected in the prescribing information. (Allopurinol label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Concomitant Respiratory Medications SPIRIVA RESPIMAT has been used concomitantly with short-acting and long-acting sympathomimetic (beta-agonists) bronchodilators, methylxanthines, oral and inhaled steroids, antihistamines, mucolytics, leukotriene modifiers, cromones, and anti-IgE treatment without increases in adverse reactions. (Tiotropium label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Upon initiation or discontinuation of TOFIDENCE, in patients being treated with these types of medicinal products, perform therapeutic monitoring of effect (e.g., warfarin) or drug concentration (e.g., cyclosporine or theophylline) and the individual dose of the medicinal product adjusted as needed. (Tocilizumab label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently. (Allopurinol label, Warnings and precautions)

• Effect of Smoking Cessation on Other Drugs: Pharmacokinetics or pharmacodynamics of certain drugs (e.g., theophylline, warfarin, insulin) may be altered, necessitating dose adjustment. (Varenicline label, Drug interactions)

Theophylline Verapamil may inhibit the clearance and increase the plasma levels of theophylline. (Verapamil label, Drug interactions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Assess INR frequently and adjust warfarin dosage accordingly when allopurinol is added to warfarin therapy. (Allopurinol label, Drug interactions)

Coadministration of zafirlukast (20 mg/day) or placebo at steady-state with a single dose of sustained release theophylline preparation (16 mg/kg) in 16 healthy boys and girls (6 through 11 years of age) resulted in no significant differences in the pharmacokinetic parameters of theophylline. (Zafirlukast label, Precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

In foreign marketing experience in patients with renal failure, use of allopurinol concomitantly with captopril has been associated with neutropenia but this association has not appeared in U.S. reports. (Captopril label, Warnings)

ATROVENT HFA has been used concomitantly with other drugs, including sympathomimetic bronchodilators, methylxanthines, oral and inhaled steroids commonly used in the treatment of COPD. (Ipratropium label, Drug interactions)

Acetazolamide, Urea, Xanthine Preparations, Alkalinizing Agents Clinical Impact: Concomitant use can lower serum lithium concentrations by increasing urinary lithium excretion. (Lithium label, Drug interactions)

…digoxin; (2) hypoglycemics–insulin, chlorpropamide, phenformin, tolazamide, and tolbutamide; (3) tranquilizers and sedatives–chlordiazepoxide, diazepam, and phenobarbital; (4) antigout–allopurinol, colchicine, and probenecid; (5) antiarrhythmics–procainamide, propranolol (see WARNINGS however), and quinidine; and (6) analgesics, antipyretics and anti-inflammatories–propoxyphene,… (Prazosin label, Drug interactions)

Hepatotoxic Drugs Clinical trials in ALS patients excluded patients on concomitant medications which were potentially hepatotoxic (e.g., allopurinol, methyldopa, sulfasalazine). (Riluzole label, Drug interactions)

The effect on CYP1A2 was explored further in a clinical interaction study with theophylline and no effect on metabolism was observed. (Alosetron label, Drug interactions)

Other Drugs: In healthy volunteers, amlodipine, phenytoin, glyburide, ranitidine, omeprazole, hormone replacement therapy (a combination of conjugated estrogens and medroxyprogesterone), antacid (aluminum and magnesium hydroxides), and theophylline did not affect the pharmacokinetics of dofetilide. (Dofetilide label, Drug interactions)

…Penciclovir No clinically significant alterations in penciclovir pharmacokinetics were observed following single-dose administration of 500 mg famciclovir after pretreatment with multiple doses of allopurinol, cimetidine, theophylline, zidovudine, promethazine, when given shortly after an antacid (magnesium and aluminum hydroxide), or concomitantly with emtricitabine. (Famciclovir label, Drug interactions)

Compounds that have been tested in man have included antipyrine, digoxin, propranolol, theophylline, and warfarin and no clinically meaningful interactions were found. (Finasteride label, Drug interactions)

No dose adjustment is needed when SINGULAIR is co-administered with theophylline, prednisone, prednisolone, oral contraceptives, fexofenadine, digoxin, warfarin, gemfibrozil, itraconazole, thyroid hormones, sedative hypnotics, non-steroidal anti-inflammatory agents, benzodiazepines, decongestants, and Cytochrome P450 (CYP) enzyme inducers [see Clinical Pharmacology… (Montelukast label, Drug interactions)

Drug Interactions No interactions have been observed between nizatidine and theophylline, chlordiazepoxide, lorazepam, lidocaine, phenytoin, and warfarin. (Nizatidine label, Drug interactions)