Classification of some agents, based on different national bodies Pharmaceutical agent Australia United States Acetylsalicylic acid (aspirin) C D third trimester Amoxicillin A B Amoxicillin with clavulanic acid B1 B Cefotaxime B1 B Diclofenac C D third trimester Isotretinoin X X Leflunomide X X Loperamide B3 C[7] Paracetamol (acetaminophen) A C[8] Paroxetine D D Phenytoin D D Rifampicin C C Thalidomide X X Theophylline A C Temazepam C X Tetracycline D D Triamcinolone (skin) A C