Sulfamethoxazole and trimethoprim Side Effects
Please note - some side effects for Sulfamethoxazole and trimethoprim may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.
Side Effects by Body System - for Healthcare Professionals
Applies to: intravenous solution; oral suspension; oral tablet
The most common side effects have included nausea, vomiting, anorexia, rash, and urticaria. Side effects generally are more common and more severe in patients with AIDS.
The most frequently reported serious adverse reactions in elderly patients have included severe skin reactions, generalized bone marrow suppression, and decreased platelets.
Sulfonamides have rarely been associated with fatal reactions, including Stevens-Johnson syndrome, toxic epidermal necrolysis, fulminant hepatic necrosis, agranulocytosis, aplastic anemia, and other blood dyscrasias.
Adverse reactions to TMP-SMX occur in 50% to 100% of patients with AIDS, compared to approximately 14% in those without AIDS receiving treatment for Pneumocystis jiroveci (formerly P carinii) pneumonia. Up to 57% of AIDS patients treated with TMP-SMX require a change in therapy due to adverse effects.
Dermatologic side effects have been reported the most frequently with TMP-SMX and are usually due to hypersensitivity to the SMX component. These have included mild erythroderma (up to 6%), severe exfoliative dermatitis, and toxic epidermal necrolysis. A few cases of acute febrile neutrophilic dermatosis (Sweet's syndrome), characterized by abrupt onset of painful erythematous plaques or nodules and a fever greater than 38 degrees C, have been reported. Phototoxicity has been reported with both TMP and SMX.
Gastrointestinal side effects have included nausea, vomiting, diarrhea, stomatitis, glossitis, abdominal pain, anorexia, pseudomembranous colitis, and pancreatitis.
The use of TMP-SMX is associated with large increases in the risk of Stevens-Johnson syndrome or toxic epidermal necrolysis, although these phenomena are rare as a whole.
A case of fixed drug eruption due to polysensitivity (TMP-SMX and tenoxicam) and reactivation of previous (10 years earlier) TMP-SMX-associated fixed drug eruption lesions has been reported.
A 48-year-old male developed liver failure, renal failure requiring hemodialysis, and pancytopenia requiring blood transfusions after 10 days of treatment with TMP-SMX for pyelonephritis. This was believed to be a hypersensitivity reaction. He was a slow acetylator phenotype and had concurrently taken acetaminophen and diclofenac; the acetaminophen may have contributed to the reaction by inhibiting NAT2.
Hypersensitivity side effects have included urticaria, rash, anaphylaxis, allergic myocarditis, erythema multiforme, exfoliative dermatitis, angioedema, drug fever, chills, Henoch-Schonlein purpura, serum sickness-like syndrome, generalized allergic reactions or skin eruptions, conjunctival and scleral injection, photosensitivity, pruritus, periarteritis nodosa, systemic lupus erythematosus, fixed drug eruption, toxic epidermal necrolysis, Stevens-Johnson syndrome, and hepatic and/or cholestatic lesions. Hypersensitivity reactions may be more likely in patients with HIV infection, with opportunistic infections, or patients who are slow acetylators. Hypotension, pulmonary edema, and elevated serum transaminases have been reported following TMP-SMX administration to HIV-infected patients. Hypersensitivity reactions in some cases have included cholestatic jaundice, interstitial nephritis, liver failure, renal failure, and pancytopenia.
Hematologic side effects have rarely included eosinophilia, hypoprothrombinemia, methemoglobinemia, thrombocytopenia, neutropenia, leukopenia, agranulocytosis, and hemolytic, megaloblastic, and aplastic anemias. Hypouricemia has been associated with high-dose therapy. Thrombotic thrombocytopenic purpura and idiopathic thrombocytopenic purpura have been reported during postmarketing experience.
Because TMP inhibits a step in folate synthesis, patients that are likely to have preexisting folate deficiencies (e.g., alcoholics, malnourished patients, patients on phenytoin or antifolate metabolites, and those with chronic hemolysis) are at risk of developing megaloblastic anemia during TMP-SMX therapy. Folate replenishment reverses this effect.
Methemoglobinemia occurred twice in an HIV-infected patient who inadvertently received TMP-SMX a second time after the first course was discontinued due to development of methemoglobinemia.
Exacerbation of posthypoxic action myoclonus occurred in a patient with non-Hodgkin's lymphoma who was receiving high-dose intravenous TMP-SMX (115 mg/kg/day) for suspected Pneumocystis pneumonia.
HIV-infected patients receiving high-dose intravenous TMP-SMX appear to have a greater incidence of tremors. The tremors generally appear several days after initiating therapy and resolve several days after discontinuation or dose reduction.
An 82-year-old male developed higher-level gait disorder on day 37 of treatment, 2 days after his dosage was doubled to TMP 1600 mg-SMX 320 mg orally twice a day. During this time, the patient also had nocturnal delirium. TMP-SMX was discontinued on day 48 and the patient's gait returned to normal and his nocturnal delirium resolved by day 51.
Nervous system side effects have included headache, irritability, confusion, disorientation, dizziness, tremors, vertigo, ataxia, peripheral neuritis, lightheadedness, insomnia, coma, catatonia, seizures, aseptic meningitis, multifocal myoclonus, bilateral asterixis, exacerbation of posthypoxic action myoclonus, and nocturnal delirium. At least one case of higher-level gait disorder has been reported.
TMP inhibits renal tubular creatinine secretion, which can result in a significant decrease in creatinine clearance. These changes appear to be completely reversible upon discontinuation of therapy. SMX may cause sulfa crystalluria, especially during low urine output states.
Interstitial nephritis and tubular necrosis may be due to hypersensitivity.
The propylene glycol vehicle in intravenous sulfamethoxazole-trimethoprim and lorazepam has also been implicated in the development of acute tubular necrosis in a patient.
Hyperkalemia has occurred with both standard and high-dose therapy. Reported cases have resolved upon discontinuation of the drug, although a few have required treatment with sodium polystyrene sulfonate. Up to 20% of patients with AIDS who are given TMP-SMX for Pneumocystis pneumonia develop mild hyperkalemia.
Renal side effects have included renal failure, interstitial nephritis, elevated BUN and serum creatinine, toxic nephrosis with oliguria and anuria, tubular necrosis, crystalluria, and aggravation of renal disease. In addition, hyperkalemia may occur as a result of the blocking of sodium channels by trimethoprim, which causes a reduction of potassium excretion in the distal tubule. Cases of azotemia and hyperkalemic renal tubular acidosis have been reported. TMP-SMX may interfere with creatinine determinations by the Jaffe alkaline picrate assay, resulting in overestimations of normal values.
Hepatic side effects have included elevated liver function tests, jaundice secondary to cholestasis, fulminant hepatic failure, hepatic necrosis, hepatitis with simultaneous pancreatitis, and hepatorenal failure. Cases of cholestatic liver disease with ductopenia have also been reported.
Cholestatic hepatitis associated with TMP-SMX therapy may present with other signs of hypersensitivity, such as rash, fever, and eosinophilia. Biopsy findings in patients with TMP-SMX-associated cholestatic hepatitis have included hepatic necrosis, hepatocyte degeneration, hepatic granuloma, centrilobular congestion, and inflammatory infiltrates.
A 34-year-old female developed pancreatitis and hepatitis after inadvertently receiving TMP-SMX for treatment of a urinary tract infection several years after experiencing a previous episode of TMP-SMX-associated hepatitis.
Metabolic side effects have included metabolic acidosis, hypoglycemia (in patients with renal failure), hyperkalemia, and hyponatremia.
High doses of intravenous TMP-SMX appear to be associated with a greater incidence of metabolic acidosis.
Sulfonamides may induce hypoglycemia. However, the establishment of a causal relationship has been difficult in most cases of suspected sulfa-induced hypoglycemia because many of the affected patients had AIDS, may have had another viral infection, or were on other medications.
Other side effects have included a sepsis-like syndrome (hypotension, fever, rash, and pulmonary infiltrates), weakness, fatigue, and facial edema.
Local reactions associated with intravenous administration have infrequently included pain and irritation and rarely thrombophlebitis.
Psychiatric side effects have included depression, hallucinations, exacerbation of panic attacks, acute psychoses, nervousness, and apathy.
Endocrine side effects associated with sulfonamides have rarely included diuresis and goiter production.
Musculoskeletal side effects have included arthralgia and myalgia. Cases of rhabdomyolysis have been reported, primarily in patients with AIDS.
Respiratory side effects have included hypersensitivity reactions of the respiratory tract, including pulmonary infiltrates, cough, and shortness of breath.
Genitourinary side effects have included significant reductions in male sperm counts after 1 month of therapy.Top
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