Phenmetrazine Barbiturates

Drugs that may affect barbiturates include alcohol, charcoal, chloramphenicol, MAO inhibitors, rifampin, and valproic acid. Drugs that may be affected by barbiturates include acetaminophen, anticoagulants, beta blockers, carbamazepine, chloramphenicol, clonazepam, oral contraceptives, corticosteroids, digitoxin, doxorubicin, doxycycline, felodipine, fenoprofen, griseofulvin, hydantoins, methoxyflurane, metronidazole, narcotics, phenmetrazine, phenylbutazone, quinidine, theophylline, and verapamil. 

Class B includes oral amphetamines, barbiturates, codeine, ethylmorphine, glutethimide, pentazocine, phenmetrazine and pholcodine. 

A comparative study in 50 overweight adults, of the effects of phenmetrazine 25 mg three times daily with or without amobarbital 30 mg three times daily, found that although the adverse CNS effects, particularly insomnia, headache and nervousness, were decreased by the presence of the barbiturate, the weight-reducing effects were also decreased (by 65%). ... 

---