Butabarbital sodium, mephobarbital, phenobarbital, pentobarbital, secobarbital barbiturate sedatives and/or hypnotics Bitosol Sodium, Mebaral, Nembutal, Phenobarbital, Seconal
carbamazepine anticonvulsant for epilepsy and trigeminal neuralgia Atretol, Tegretol
ethanol chronic use wine, beer, whiskey, etc.
phenytoin control of seizures Dilantin
rifampin Treatment of pulmonary tuberculosis Rifadin, Rifamate, Rifater, Rimactane
urinary acidifiers, ascorbic acid keeps calcium soluble, controls urine-induced skin irritations, vitamin C K-Phos, Vitamin C (large doses)

 

Drugs Which May Increase Plasma Levels of Methadone or Increase Methadone EffectsGeneric

 

amitriptyline treatment of depression and anxiety Elavil, Endep, Entrafon, Limbitrol, Triavil
cimetidine H2 receptor antagonist for the treatment of gastric and duodenal ulcers, and gastric reflux disease Tagamet
diazepam control of anxiety and stress Dizac Vairelease, Valium
ethanol acute use wine, beer, whiskey, etc.
fluvoxamine maleate serotonin reuptake inhibitor for treatment of depression and compulsive disorders Luvox
ketoconazole anti-fungal agent Nizoral Tablets
urinary alkalinizers treatment of kidney stones, gout therapy Bicitra, Polycitra

Charts from A.T. Forum, (1997, Spring). Vol. VI, #2, p. 3.
Some drugs that cause false positives