| GENERIC NAME |
COMBINED EFFECT |
|
|
|
| ------------------------- |
----------------------- |
| Amiodarone |
Increased anticonvulsant effect. |
| Antacids* |
Decreased anticonvulsant effect. |
| Anticoagulants* |
Increased effect of both drugs. |
| Antidepressants, |
May need to adjust anticonvulsant dose. |
|
|
|
| Barbiturates* |
Changed seizure pattern. |
| Calcium |
Decreased effects of both drugs. |
| Carbamazepine |
Possible increased anticonvulsant |
| |
metabolism. |
| Carbonic anhydrase |
Increased chance of bone disease. |
|
|
|
| Central nervous |
Oversedation. |
|
|
|
|
|
|
| Chloramphenicol |
Increased anticonvulsant effect. |
| Cimetidine |
Increased anticonvulsant toxicity. |
| Contraceptives, oral* |
Increased seizures. |
| Cortisone drugs* |
Decreased cortisone effect. |
| Cyclosporine |
May decrease cyclosporine effect. |
| Digitalis |
Decreased digitalis effect. |
|
|
|
| Disopyramide |
Decreased disopyramide effect. |
| Disulfiram |
Increased anticonvulsant effect. |
| Estrogens* |
Increased estrogen effect. |
| Felbamate |
Increased side effects and adverse |
| |
reactions. |
| Fluconazole |
Increased anticonvulsant effect. |
| Furosemide |
Decreased furosemide effect. |
| Gold compounds* |
Increased anticonvulsant blood levels. |
| |
Hydantoin dose may require adjustment. |
| Glutethimide |
Decreased anticonvulsant effect. |
| Griseofulvin |
Increased griseofulvin effect. |
| Hypoglycemics, oral* |
Possible decreased hypoglycemic effect. |
| Hypoglycemics, other* |
Possible decreased hypoglycemic effect. |
| Isoniazid |
Increased anticonvulsant effect. |
| Itraconazole |
Decreased itrconazole effect. |
| Leucovorin |
May counteract the effect of phenytoin |
| |
or any hydantoin anticonvulsant. |
| Loxapine |
Decreased anticonvulsant effect of |
| |
phenytoin or any hydantoin anti- |
| |
convulsant. |
| MAO inhibitors* |
Increased polythiazide effect. |
| Methadone |
Decreased methadone effect. |
| Methotrexate |
Increased methotrexate effect. |
| Methylphenidate |
Increased anticonvulsant effect. |
| Molindone |
Increased phenytoin effect. |
| Nicardipine |
Increased anticonvulsant effect. |
| Nimodipine |
Increased anticonvulsant effect. |
| Nitrates* |
Excessive blood pressure drop. |
| Nizatidine |
Increased effect and toxicity of |
| |
phenytoin. |
| Omeprazole |
Delayed excretion of phenytoin |
| |
causing increased amount of phenytoin |
| |
in blood. |
| Oxyphenbutazone |
Increased anticonvulsant effect. |
| Para-aminosalycylic |
Increased anticonvulsant effect. |
|
|
|
| Paroxetine |
Decreased anticonvulsant effect. |
| Phenacemide |
Increased risk of paranoid symptoms. |
| Phenothiazines* |
Increased anticonvulsant effect. |
| Phenylbutazone |
Increased anticonvulsant effect. |
| Potassium supplements* |
Decreased potassium effect. |
| Probenecid |
Decreased probenecid effect. |
| Propafenone |
Increased effect of both drugs and |
| |
increased risk of toxicity. |
| Propranolol |
Increased propranolol effect. |
| Quinidine |
Increased quinidine effect. |
| Rifampin |
Decreased anticonvulsant effect. |
| Sedatives* |
Increased sedative effect. |
| Sotalol |
Decreased sotalol effect. |
| Sucralfate |
Decreased anticonvulsant effect. |
| Sulfa drugs* |
Increased anticonvulsant effect. |
| Theophylline |
Reduced anticonvulsant effect. |
| Trimethoprim |
Increased phenytoin effect. |
| Valproic acid |
Breakthrough seizures. |
| Xanthines* |
Decreased effects of both drugs. |