Current Drug Safety - Volume 19, Issue 1, 2024

Background: Methemoglobinemia is a life-threatening disorder, with levels above 1 percent considered abnormal and typically resulting from drug or toxic substance exposure. Case Presentation: In this study, we describe a case of a 43-year-old woman with a long-standing complaint of fatigue. Iron deficiency anemia was diagnosed based on the blood test findings of hemoglobin of 101 g/L, mean red blood cell volume of 75 fL, ferritin of 2.81 ug/L, transferrin saturation of 4.3 percent, and C-reactive protein of 0.6 mg/L. As a preferred treatment option, 1000 mg ferric carboxymaltose on two distinct days was preferred. After administering the first dose of the medication, we noticed incidentally that methemoglobin levels increased to 2.3%. When venous blood gas was repeated before and after administration of the second dose of the drug, methemoglobin levels were found to be 0.8% and 1.8%, respectively. There was no change in vital signs in both two dosages, and she only suffered a temporary sore throat. Her anemia improved with intravenous iron therapy, and she is currently being followed in our clinic. Conclusion: No case or research reporting an increase in methemoglobin levels following oral and/or intravenous treatment to patients with iron deficiency anemia has been found in the literature. Therefore, this is the first contribution to the existing literature.

Introduction: We reported a patient with rheumatoid arthritis who received chronic methotrexate (MTX) therapy and experienced several adverse reactions like hemocytopenia and renal impairment. Under the monitoring of the therapeutic drug concentration, calcium folate and other measures were used to accelerate methotrexate excretion and eliminate adverse reactions. Case Presentation: A 66-year-old man with rheumatoid arthritis received MTX and developed adverse effects of bone marrow suppression, like pancytopenia. He had a black stool, and he tested positive for occult blood, which was considered gastrointestinal bleeding. The blood MTX concentration reached 4.07 μmol/L, and leucovorin was administered to rescue the patient's life. Besides, hydration and alkaline urine were applied to quickly clear methotrexate inside the body. Conclusion: Low-dose MTX has fewer adverse reactions but may cause bone marrow suppression- related side effects. Blood concentration monitoring can be used to guide the rescue of MTX poisoning.

Background: Phenprocoumon is a vitamin K antagonist that is widely prescribed in Europe and Latin America for the prophylaxis and treatment of thromboembolic events. Case Presentation: A 90-year-old female was admitted to our hospital with tonic-clonic seizures, possibly due to dementia syndrome. Valproic acid (VPA) was prescribed for the treatment of seizures. VPA is an inhibitor of cytochrome P450 (CYP) 2C9 enzymes. A pharmacokinetic interaction with phenprocoumon occurred, which is a substrate for CYP2C9 enzymes. The interaction resulted in a strong INR increase and subsequent clinically relevant bleeding in our patient. Valproic acid is not specifically mentioned in the phenprocoumon drug label as a CYP2C9 inhibitor, and in the Dutch medication surveillance database, no medication alert is shown when prescribing this combination, and no interaction with phenprocoumon has been reported so far. Conclusion: When prescribing this combination, the prescriber should be warned and advised to intensify INR monitoring if the combination is to be continued.

Background: The development of direct-acting antivirals directed against the Hepatitis C Virus has dramatically modified the therapeutic approach to chronic hepatic viral disease. Larger use of such drugs has also led to increasing reports about their adverse effects. This report aimed to describe a case of leucocytoclasic vasculitis following treatment based on the sofosbuvir/ledipasvir regimen with complete disappearance shortly after withdrawal in a 61-year-old patient treated for genotype 1 hepatitis C. Case Presentation: A 61-year-old Tunisian woman with a history of hepatitis C virus genotype 1 infection developed palpable purpura in front of low extremity articulation, five weeks after the onset of sofosbuvir/Ledipasvir. The histological examination concluded with leucocytoclasic vasculitis, with total disappearance three days after withdrawal. The pre-therapeutic assessment showed no positivity of Cryoglobulinemia. Anti-neutrophil cytoplasmic antibodies (ANCA) were negative. A sustained viral response was obtained only 5 weeks after treatment without an increase of viral load during follow-up. Conclusion: There was a temporal relationship between antiviral treatment and non-ANCA skin vasculitis. The pharmacological department concluded the imputability of antiviral treatment (score I2B2).

Introduction: Pantoprazole is a proton pump inhibitor mainly used to treat conditions causing excess stomach acid. Stevens-Johnson syndrome (SJS) is a rare bullous disease. The main etiologic factors are drugs, especially antibiotics, anticonvulsants, oxicam and allopurinol. Proton pump inhibitors have been rarely reported as a causative agent in SJS, and only sporadic cases secondary to pantoprazole have just been mentioned in the literature. Case Report: A 49-year-old woman was referred to the dermatology department for a pruritic generalized eruption, associated with erosive cheilitis. The patient reported self-medication by pantoprazole for two weeks. Physical examination revealed target-like lesions with bullous center in some areas. A skin detachment on the left breast and the neck affecting 10% of the total body surface area was observed. Mucosal examination revealed erosive, painful cheilitis covered by large hemorrhagic crusts and erosions of the nasal cavity. The lesions cleared completely few days after pantoprazole withdrawal and local corticosteroids. Further investigations ruled out infectious etiologies. Conclusion: This case highlights the possible occurrence of hypersensitivity reactions due to the use of a PPI, which is a widely used medication and a generally well-tolerated drug.

>Introduction: Linezolid is increasingly utilized to treat gram-positive bacteria that are resistant to other antibiotics like vancomycin-resistant Staphylococcus aureus, methicillinresistant Staphylococcus aureus as well as drug-resistant tuberculosis. It acts by inhibiting protein synthesis in bacteria. Although it is a relatively safe medicine, many reports of hepatotoxicity and neurotoxicity linked to long-term usage have been received but patients with pre-existing risk factors, such as diabetes and alcoholism, may have toxicity even after short-term use of linezolid. Case Presentation: Here we are presenting a case of a 65-year-old female with diabetes who developed hepatic encephalopathy after one week of treatment with linezolid prescribed for nonhealing diabetic ulcer after a culture sensitivity test. After the use of linezolid 600 mg BD for 8 days patient developed altered sensorium and breathlessness and had high bilirubin, SGOT, and SGPT. She was diagnosed with hepatic encephalopathy. Linezolid was withdrawn and after 10 days all laboratory parameters for liver function test were improved. Conclusion: Care should be taken when prescribing linezolid in such patients with pre-existing risk factors as they are prone to develop hepatotoxic and neurotoxic adverse effects even after short-term use of linezolid.

Introduction: Reported cases after the post-commercialization phase of mRNA vaccines against COVID-19 have revealed that myocarditis and pericarditis may occur predominantly in male adolescents after the second dose of the vaccine. Case Presentation: We report two cases of cardiac disorders associated with mRNA COVID-19 vaccination, both of them in 15 year-old males. One of the patients presented acute pericarditis and the second one presented acute myocarditis with left ventricular dysfunction at hospital discharge. Discussion and Conclusion: Physicians should be aware with the typical manifestations of these cardiovascular events after the vaccination and report suspicious cases to pharmacovigilance agencies as soon as possible. The population should rely on the pharmacovigilance system that continues to recommend vaccination as the most effective strategy to reduce the negative consequences of the pandemic.