<unk>  has a potential of blood-related toxicity (blood dyscrasias), but causes less kidney, cardiovascular, and gastrointestinal toxicity than non-steroidal anti-inflammatory drugs (NSAIDs). Like NSAIDs, it can trigger bronchospasm or anaphylaxis, especially in those with asthma. Serious side effects include agranulocytosis, aplastic anaemia, hypersensitivity reactions (like anaphylaxis and bronchospasm), toxic epidermal necrolysis and it may provoke acute attacks of porphyria, as it is chemically related to the sulfonamides. The relative risk for agranulocytosis appears to greatly vary according to the country of estimates on said rate and opinion on the risk is strongly divided. Genetics may play a significant role in<unk>  sensitivity. It is suggested that some populations are more prone to suffer from<unk>  induced agranulocytosis than others. As an example,<unk> -related agranulocytosis seems to be an adverse effect more frequent in British population as opposed to Spaniards. According to a systematic review from 2016<unk>  significantly increased the risk of upper gastrointestinal bleeding by a factor ranging from 1.4 to 2.7 (relative risk). Contraindications Previous hypersensitivity (such as agranulocytosis or anaphylaxis) to<unk>  or any of the excipients (e.g. lactose) in the preparation used, acute porphyria, impaired haematopoiesis (such as due to treatment with chemotherapy agents), third trimester of pregnancy (potential for adverse effects in the newborn), lactation, children with a body weight below 16 kg, history of aspirin-induced asthma and other hypersensitivity reactions to analgesics. + Known interactions Drug(s) Interaction/reason for theoretical potential for interaction Ciclosporin Decreased serum levels of ciclosporin. Chlorpromazine Additive hypothermia (low body temperature) may result. Methotrexate Additive risk for haematologic (blood) toxicity. Oral anticoagulants (blood thinners), lithium, captopril, triamterene and antihypertensives may also interact with<unk> , as other pyrazolones are known to interact adversely with these substances. Overdose It is considered fairly safe on overdose, but in these cases supportive measures are usually advised as well as measures to limit absorption (such as activated charcoal) and accelerate excretion (such as haemodialysis).
Metamizole
Astemizole
Sodium azide
Eflornithine
Miproxifene phosphate
Fursultiamine
Mesocarb
Amifampridine