1. Paracetamol overdose : depletion glutathione ,NAPQI ; n acetyl p bennzquinone Imine. 2. ASPIRIN : it causes Rye syndrome (6 months to 18 year old ), risk of bleeding . 3. SILDENAFIL CITRATE : inhibits PDE 5 (phosphodieaterase type 5 ) . 4. SENNA : weaker laxative than biscodyl and castor oil 5. PENCILLAMINE : chelating agent to treat WILSONS DISEASE , CYSTINURIA .