| 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. |