He metamizole It is the best-selling medicine in Spain and is indicated to combat acute pain and fever. Known in Spain under the brand Nolotilhas good digestive tolerance, unlike some anti-inflammatories such as ibuprofen. However, like all drugs, it has possible side effectssome of them serious. Therefore, they must be taken with caution, no more than a week in a row and under a doctor’s prescription.
The most adverse effect of Nolotil is agranulocytosisa hematological disease that occurs when the level of granulocytes in the blood (neutrophils, eosinophils and basophils) is low, which decreases the body’s ability to fight germs and, by extension, infections.
According to what the pharmaceutical companies that are authorized to sell the drug in Spain to health professionals have warned, they are serious and worrying. This past Monday they sent them a letter with the alert and recommendations. Specifically, “early symptoms that suggest agranulocytosis are fever, chills, sore throat and painful changes in the mucous membranes, especially in the mouth, nose and throat, or in the genital or anal area.” In this regard, they warn that “agranulocytosis, which can cause serious and life-threatening infections, is a known adverse reaction of medications containing metamizole.”
Communication, distributed and supervised by the European Medicines Agency (EMA) and the Spanish Agency for Medicines and Health Products (AEMPS), emphasizes the need for physicians to be attentive to these symptoms, given that agranulocytosis can manifest at any time during treatment with metamizole (Nolotil), and even shortly after its completion. ending.
More benefits than risks, according to the EMA
Although a recent EMA report concludes that the benefits of metamizole outweigh its risksthis drug has been under surveillance due to cases of decrease in granulocytes, crucial immune cells, which in severe situations can be fatal. Even in some countries like The UK bans metamizole (Nolotil). The Government of Spain, however, downplays the risk due to low incidence.
Masked symptoms
The letter highlights the importance of stopping treatment and seeking immediate medical attention if these symptoms occur. He also warns that if metamizole is taken to treat fever, some of these signs may not be evident, especially if the patient is on antibiotics.
“If signs and symptoms suggest agranulocytosis, a complete blood count should be performed immediately, including formula leukocyte, and discontinue treatment while awaiting results,” the letter reads. “If agranulocytosis is confirmed, treatment should not be restarted.”
Pharmaceutical companies also remind that, following a European review, the contraindications, warnings and precautions related to the use of medicines containing metamizole have been reviewed to minimize serious outcomes associated with the risk of agranulocytosis. This updated information will be incorporated into both the technical sheet for health professionals as well as for patients.
Agranulocytosis: a dangerous condition
Agranulocytosis is characterized by a sudden drop in granulocytes, a type of white blood cell essential for defense against infections. The lack of granulocytes leaves the patient vulnerable to serious and life-threatening infections. This adverse effect is the most dangerous associated
Other adverse effects of metamizole, the active ingredient in Nolotil
As warned by the CIMA (Spanish Agency for Medicines and Health Products) in the technical data sheet of this active ingredient, metamizole can have several side effectsfrom the mildest, such as a slight drop in blood pressure (something that happens to one in ten patients), to rashes in one in 100, allergic reactions in one in 1,000 or other very rare ones, such as or agranulocytosis or serious kidney and liver problems.
In general, we can divide the adverse effects in five groups:
Hematological
Metamizole can cause leukopeniawhich is a decrease in the number of white blood cells in the blood. If this decrease is very severe, it is known as agranulocytosis, a very rare but very serious side effect, as it can compromise the patient’s life. This reaction does not depend on the dose and can appear at any time, and even in patients who have previously received metamizole without problems. Metamizole can also reduce the number of red blood cells and platelets.
Allergic reactions
Metamizole can cause allergic reactions of lesser or greater severity, from skin rashes, hives or rhinosinusitis to asthma or anaphylactic shocksomething very rare. For this reason, it is recommended that people with asthma or atopy take it with caution and in the case of patients at high risk of anaphylactoid reactions, assess whether treatment is appropriate.
in blood pressure
In one in 10 patients, blood pressure may drop, especially in patients with pre-existing arterial hypotension, hypovolemia, dehydration, circulatory instability, incipient circulatory insufficiency or with very high fever. In these cases, hypotension can become severe.
skin reactions
Although very rare, metamizole can cause serious skin reactions, such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug reaction with eosinophilia and systemic symptoms (DRESS)which can be life-threatening or serious. The first warning sign is the appearance of vesicles or blisters, erythema, ulcers in the mouth or
Hepatic
In some cases, cases of hepatitis have been reported, manifesting with symptoms such as jaundice, skin rashes, fever, increased blood level of liver enzymes… Most patients recover after stopping treatment, but in isolated cases it progressed to even acute liver failure.
Kidney
In rare cases, metamizole may cause kidney damage, which manifests itself as inflammation of the kidney (interstitial nephritis), a decrease or suppression of urine output, an increase in the amount of protein excreted in the urine, or chromaturia (abnormal coloration of the urine). urine).
Other very rare side effects
They can be gastrointestinal bleeding, Kounis syndrome (a type of heart disorder) or sepsis (serious infection involving an inflammatory reaction of the entire body).
When to see a doctor
As warn from the Spanish Agency of Medicines and Health ProductsIf we are taking metamizole and notice any of these symptoms, we must go to a medical center as soon as possible:
- Feeling of illness: nausea, vomiting, fever, feeling tired, loss of appetite.
- Very dark urine.
- Symptoms of liver damagesuch as light-colored stools, yellowing of the skin or the whites of the eyes, itching, rash, or pain in the upper stomach area.
- Signs of allergic reactionssuch as skin and mucous membrane reactions (itching, burning, redness, swelling, hives…), difficulty breathing, swelling of feet, hands, lips, throat or respiratory tract…
- Hematological or cardiac signs: alterations in heart rhythm and decreased blood pressure, very pale skin, fatigue…
In addition, it is recommended that you do not take metamizole people who have previously had allergic reactions or hematological reactions with medications containing metamizole or other similar compounds, have suffered symptoms of asthma, rhinitis or urticaria, suffer from acute porphyria, genetic deficiency of glucose-6-phosphate dehydrogenase, have suffered alterations in bone marrow function and during pregnancy and lactation.