Metamizol (dipyrone) for pain therapy. A literature review and own clinical experiences

Objective: This article presents the current knowledge of pharmacology and clinical effects of Metamizol (Dipyrone) in dogs, cats and rodents. In the last years Metamizol has experienced a revival especially in human medicine. For long times Metamizol was known as a weak analgesic with especially antipyretic effects. The pharmacological effects were unknown for a long time. Today it is proven that central and peripheral effects are responsible for the potent analgesic efficacy of Metamizol. Opioiderg pathways and inhibition of the cyclooxygenases are proved mechanisms for the effects of this drug. Metamizol also shows antipyretic, weak antiphlogistic, spasmolytic and anticonvulsive effects. The analgesic efficacy is comparable to that of opioids. The side-effect of hypotension after intravenous injection can be avoided by slow injection. Agranulocytosis was never seen in veterinary medicine until now and is a side effect with an incidence of only 0.008% in human medicine. The gastro-intestinal tolerance of Metamizol is very good. Conclusion and clinical relevance: This article shows that Metamizol is an analgesic which is also very effective and well tolerated in veterinary patients.