Following the suspicions that thrombosis has been raised after the administration of the AstraZeneca vaccine, it is worth remembering that several hundred drugs have been linked to the drug-induced thrombocytopenia (TCPIF). TCPIF patients have a decrease in platelet count 5 to 10 days after drug administration with an increased risk of bleeding.
Diagnosis, furthermore, is often challenging, because most hospitalized patients take multiple medications and have comorbidities that can also cause thrombocytopenia.
Heparin
The European Medicines Agency (EMA) has announced that it is possible to associate rare cases of blood clots and low levels of blood platelets with the AstraZeneca vaccine, so it should appear as a "very rare" side effect, with a probability of <1/10,000.
The first cases of thrombosis after vaccination with AstraZeneca were detected between 3 and 14 days after dosing. The patients presented a "very intense headache that worsened when lying down and did not improve with analgesics", there were even cases that also presented "vomiting or irregular bleeding." This last condition is what is known clinically as thrombocytopenia.
More than 300 drugs have been implicated in TCPIF. A systematic review of individual patient data found that the most frequently reported drugs with a definite or probable causal relationship with thrombocytopenia were quinine, quinidine, trimethoprim/sulfamethoxazole, vancomycin, penicillin, rifampin, carbamazepine, ceftriaxone, ibuprofen, mirtazapine, oxaliplatin. as well as the glycoprotein IIb/IIIa (GPIIb/IIa) inhibitors abciximab, Tirofiban, and eptifibatide.
The review included 273 patients (61.5% men), mean age 60 ± 15 years. The average stay was 18 ± 17 days. The incidence of thrombocytopenia was 2.26%. The most involved services were Hematology (56), Intensive Medicine (48) and Oncology (40). Thrombocytopenia was moderate in 69% of the cases, in 26 in % mild and in 5% severe.
There were 8 cases of drug-induced thrombocytopenia (incidence 0.063%), resolved in a mean of 7.6 days. Related medications were enoxaparin (2), linezolid (2), tacrolimus (2), thymoglobulin (1), and heparin (1). The doctor was recommended to suspend the drug (2), reduce the dose (3) or monitor it (3), with an acceptance of 100%.
However, The most common drug involved in DITP is usually heparin. Life-threatening thromboembolic complications are common in patients with heparin-induced thrombocytopenia (TIH). Thrombocytopenia may occur in 10 to 30% of heparin-treated patients in the absence of obvious immune system involvement.
The incidence of TCPIF is not known exactly, since case notification is voluntary and no studies designed for this purpose have been carried out. Based on various epidemiological studies in the United States and Europe, the minimum estimated incidence is around 10 cases per million inhabitants/year.
On the other hand, the incidence of TCPIF varies depending on the medications, with values from 5% to 40% in patients receiving heparin, while for other drugs it is lower than 1%. The drugs that have been most frequently related to the appearance of TCPIF are Cinchona alkaloids (quinine/quinidine), sulfonamides, NSAIDs, diuretics, anticonvulsants and tuberculostatics.
–
The news
More than 300 drugs can cause thrombosis, many of them more likely than AstraZeneca
was originally published in
Xataka Science
by
Sergio Parra
.