sulfadiazine
Regulatory sources consulted
Approved indications
- Infections due to susceptible organisms when a systemic sulfonamide is indicated, including toxoplasmosis combined with pyrimethamine.
Contraindications
Absolute
- Hypersensitivity to sulfadiazine or other sulfonamides, with possible cross-reactivity with sulfonylureas, thiazides, and carbonic anhydrase inhibitors; severe renal or hepatic impairment; porphyria; G6PD deficiency; third trimester of pregnancy; and age under 2 months.
Clinical warnings
- Severe cutaneous reactions, including Stevens-Johnson syndrome and toxic epidermal necrolysis, require immediate discontinuation at the first rash or mucosal signs. — CIMA/AEMPS, ficha técnica 06960
- Major warning · Blood dyscrasias and marrow suppression may occur; monitor blood counts, especially with high doses, prolonged treatment, folate deficiency, or renal impairment. — CIMA/AEMPS, ficha técnica 06960
- Major warning · Hemolysis may occur in G6PD deficiency; avoid high doses and monitor for anemia. — CIMA/AEMPS, ficha técnica 06960
Drug interactions
- ModeratePara-aminobenzoic acid derivatives, including procaine
Mechanism: They may antagonize sulfadiazine antibacterial activity.
Recommendation: Avoid the combination.
CIMA/AEMPS, ficha técnica 06960
- HighAnticoagulants, phenytoin, and sulfonylureas
Mechanism: Sulfadiazine may enhance their effects and toxicity through displacement or metabolic inhibition.
Recommendation: Monitor INR, phenytoin concentrations, and glucose as applicable.
CIMA/AEMPS, ficha técnica 06960
- HighMethotrexate and other myelotoxic, nephrotoxic, or hepatotoxic drugs
Mechanism: They increase hematologic, renal, or hepatic toxicity risk.
Recommendation: Avoid if possible; if combined, monitor blood counts and renal and hepatic function.
CIMA/AEMPS, ficha técnica 06960
- HighCyclosporine
Mechanism: It may reduce cyclosporine concentrations.
Recommendation: Monitor cyclosporine concentrations and renal function.
CIMA/AEMPS, ficha técnica 06960
Adverse events
Common (≥1%)
Nausea, vomiting, diarrhea, and rash
Rare but serious
Anaphylaxis, agranulocytosis, aplastic anemia, SJS/TEN, and hemolysis
Pregnancy and lactation
It is contraindicated in the third trimester and in infants younger than 2 months. At other stages, use only if essential. A decision must be made whether to discontinue breastfeeding or the drug, considering benefit to the mother.
Recent literature (PubMed)
Patients with haematological malignancies might develop life-threatening toxoplasmosis, especially after allogeneic haematopoietic stem-cell transplantation (HSCT). Reactivation of latent cysts is the primary mechanism of toxoplasmosis following HSCT; hence, patients at high risk are those who were seropositive before transplantation. The lack of trimethoprim-sulfamethoxazole prophylaxis and various immune status parameters of the patient are other associated risk factors. The mortality of toxoplasma disease-eg, with organ involvement-can be particularly high in this setting. We have developed guidelines for managing toxoplasmosis in haematology patients, through a literature review and consultation with experts. In allogeneic HSCT recipients seropositive for Toxoplasma gondii before transplant, because T gondii infection mostly precedes toxoplasma disease, we propose weekly blood screening by use of quantitative PCR (qPCR) to identify infection early as a pre-emptive strategy. As trimethoprim-sulfamethoxazole prophylaxis might fail, prophylaxis and qPCR screening should be combined. However, PCR in blood can be negative even in toxoplasma disease. The duration of prophylaxis should be a least 6 months and extended during treatment-induced immunosuppression or severe CD4 lymphopenia. If a positive qPCR test occurs, treatment with trimethoprim-sulfamethoxazole, pyrimethamine-sulfadiazine, or pyrimethamine-clindamycin should be started, and a new sample taken. If the second qPCR test is negative, clinical judgement is recommended to either continue or stop therapy and restart prophylaxis. Therapy must be continued until a minimum of two negative PCRs for infection, or for at least 6 weeks for disease. The pre-emptive approach is not indicated in seronegative HSCT recipients, after autologous transplantation, or in non-transplant haematology patients, but PCR should be performed with a high level of clinical suspicion. Sulfadiazine is a sulfonamide antibacterial agent
Toxoplasma gondii is responsible for the disease toxoplasmosis and has the broadest host range among apicomplexan parasites, as it infects virtually all warm-blooded vertebrates. Toxoplasmosis is a zoonotic and emerging public health concern with considerable morbidity and mortality, especially in the developing world, affecting approximately one-third of the world's human population. Clinical presentation varies among species, and the infection establishes lifelong chronicity in hosts. Most of the host species (including healthy humans) are asymptomatic on the one hand, it is fatal to marsupials, neotropical primates and some marine mammals on the other hand. In immunocompetent humans, infection is typically asymptomatic, whereas immunocompromised individuals may develop disseminated disease affecting virtually any organ system-most commonly reproductive, cerebral, and ocular systems. Toxoplasmosis spreads by ingestion of food or water contaminated with T. gondii oocysts, consumption of undercooked/raw meat containing tissue cysts, transplacental transmission from mother to fetus, or by receiving infected organ/blood from the infected individual. Toxoplasmosis is mainly diagnosed by serologic tests and polymerase chain reaction (PCR). It is treated with pyrimethamine combined with sulfadiazine or clindamycin, often supplemented with leucovorin, atovaquone, and dexamethasone. Despite having many potent anti-T. gondii antigenic candidates, there is no commercially available vaccine for humans due to many factors, including the complex life cycle of the parasite and its evasion strategies. To date, the only commercially available anti-T. gondii vaccine is for sheep, licensed for veterinary use to prevent ovine abortions. In this review, we have summarized the current understanding of toxoplasmosis. The sulfonamides represent a large class of antibiotics that have multiple clinical uses. The sulfonamides were the first effective antibiotics to be introduced into clinic
Advances in the understanding of equine protozoal myeloencephalitis (EPM) are reviewed. It is now apparent that EPM can be caused by either of 2 related protozoan parasites, Sarcocystis neurona and Neospora hughesi, although S neurona is the most common etiologic pathogen. Horses are commonly infected, but clinical disease occurs only infrequently; the factors influencing disease occurrence are not well understood. Epidemiologic studies have identified risk factors for the development of EPM, including the presence of opossums and prior stressful health-related events. Attempts to reproduce EPM experimentally have reliably induced antibody responses in challenged horses, but have not consistently produced neurologic disease. Diagnosis of EPM has improved by detecting intrathecal antibody production against the parasite. Sulfadiazine/pyrimethamine (ReBalance) and the triazine compounds diclazuril (Protazil) and ponazuril (Marquis) are effective anticoccidial drugs that are now available as FDA-approved treatments for EPM.