Phenobarbitone Idaman Drug Interactions

Alcohol: Concurrent administration with alcohol may lead to an additive Central Nervous System (CNS) depressant effect. This is likely with concurrent administration with other CNS depressants.
Antidepressants: Including Monoamine Oxidase Inhibitors (MAOIs), Selective Serotonin Reuptake Inhibitors (SSRIs) and tricyclics may antagonize the antiepileptic activity of phenobarbitone by lowering the convulsive threshold.
Antiepileptics: Phenobarbitone plasma concentrations increased by oxcarbazepine, phenytoin and sodium valproate. Vigabatrin possibly decreases phenobarbitone plasma concentrations.
Antipsychotics: Concurrent use of chlorpromazine and thioridazine with phenobarbitone can reduce the serum levels of either drug.
Folic acid: If folic acid supplements are given to treat folate deficiency, which can be caused by the use of phenobarbitone, the serum phenobarbitone levels may fall, leading to decreased seizure control in some patients.
Memantine: The effect of phenobarbitone is possibly reduced.
Methylphenidate: Plasma concentration of Phenobarbitone is possibly increased.
Antiarrhythmics: Disopyramide and quinidine loss of arrhythmia control is possible. Plasma levels of antiarrhythmics should be monitored if phenobarbitone is added or withdrawn. Changes in dosage may be necessary.
Antibacterials: Chloramphenicol, doxycycline, metronidazole and rifampicin. Avoid concomitant use of telithromycin during and for 2 weeks after Phenobarbitone.
Anticoagulants: Phenobarbitone increases the rate of metabolism reducing serum concentrations when taking together with anticoagulants.
Antidepressants: Phenobarbitone increases the rate of metabolism reducing serum concentrations when taking together with paroxetine, mianserin and tricyclic antidepressants.
Antiepileptics: Phenobarbitone increases the rate of metabolism reducing serum concentrations when taking together with carbamazepine, lamotrigine, tiagabine, zonisamide, primidone and possibly ethosuxamide.
Antifungals: Antifungal effects of griseofulvin can be reduced or even abolished by concurrent use. Phenobarbitone possibly reduces plasma concentrations of itraconazole or posaconazole. Avoid concomitant use of voriconazole.
Antipsychotics: Phenobarbitone possibly reduces concentration of aripiprazole.
Antivirals: Phenobarbitone possibly reduces plasma levels of abacavir, amprenavir, darunavir, lopinavir, indinavir, nelfinavir, saquinavir.
Anxiolytics and Hypnotics: Phenobarbitone increases the rate of metabolism reducing serum concentrations when taking together with clonazepam.
Aprepitant: Phenobarbitone possibly reduces plasma concentration of aprepitant.
Beta-blockers: Phenobarbitone increases the rate of metabolism reducing serum concentrations when taking together with metoprolol, timolol and possibly propranolol.
Calcium channel blockers: Phenobarbitone causes reduced levels of felodipine, isradipine, diltiazem, verapamil, nimodipine and nifedipine and an increase in dosage may be required.
Cardiac glycosides: Blood levels of digitoxin can be halved by concurrent use.
Ciclosporin or Tacrolimus: Phenobarbitone increases the rate of metabolism reducing serum concentrations when taking together with ciclosporin or tacrolimus.
Corticosteroids: Phenobarbitone increases the rate of metabolism reducing serum concentrations when taking together with corticosteroids.
Cytotoxics: Phenobarbitone possibly reduces the plasma levels of etoposide or irinotecan.
Diuretics: Concomitant use with eplerenone should be avoided.
Haloperidol: Serum levels are approximately halved by concurrent use with phenobarbitone.
Hormone antagonists: Phenobarbitone increases the rate of metabolism reducing serum concentrations when taking together with gestrinone and possibly toremifene.
Methadone: Levels can be reduced by concurrent use of phenobarbitone and withdrawal symptoms have been reported in patients maintained on methadone when phenobarbitone has been added. Increases in the methadone dosage may be necessary.
Montelukast: Phenobarbitone increases the rate of metabolism reducing serum concentrations when taking together with montelukast.
Oestrogens and Progestogens: Reduced contraceptive effect.
Sodium oxybate: Enhanced effects, avoid concomitant use.
Theophylline: May require an increase in theophylline dose.
Thyroid hormones: May increase requirements for thyroid hormones in hypothyroidism.
Tibolone: Phenobarbitone increases the rate of metabolism reducing serum concentrations when taking together with tibolone.
Tropisetron: Phenobarbitone increases the rate of metabolism reducing serum concentrations when taking together with tropisetron.
Vitamins: Barbiturates possibly increase requirements for vitamin D.