Sulfonamide allergy

The sulfonamides are used with caution in patients with renal or hepatic impairment and bronchial asthma. These drugs are given with caution to patients with allergies. Safety for use during pregnancy has not been established (Pregnancy Category C, except at term). 

The use of non-sulfapyridine-based aminosalicylates has led to greater tolerability. Although the adverse effects are similar to those of sulfasalazine, they occur at a much lower rate. Olsalazine, in particular, is associated with a higher incidence of secretory diarrhea. These agents can also be used safely in patients with a reported sulfonamide allergy. 

The most common side effects include somnolence, dizziness, anorexia, headache, nausea, word-finding difficulties, oligohidrosis, modest weight loss, and irritability. Symptomatic kidney stones may occur in 2.6% of patients. Hypersensitivity reactions may occur in 0.02% of patients, and it should be used with caution if at all in patients with a history of allergy to sulfonamides. Monitoring of renal function may be advisable in some patients. 

Hypersensitivity reactions Hypersensitivity reactions may occur in patients with or without a history of allergy or bronchial asthma cross-sensitivity with sulfonamides may also occur. Refer to Management of Acute Hypersensitivity Reactions. 

Sulfa drug allergy Probenecid is a sulfonamide patients with a history of allergy to sulfa drugs may react to probenecid. 

Sulfa allergy Use tipranavir with caution in patients with a known sulfonamide allergy. Tipranavir contains a sulfonamide moiety. 

Sulfonamide cross-sensitivity Amprenavir is a sulfonamide. The potential for cross-sensitivity between drugs in the sulfonamide class and amprenavir is unknown. Treat patients with a known sulfonamide allergy with caution. 

Uses Suppress/eluninate bacteriuria associated w/ chronic/recurrent UTI Action Converted to formaldehyde ammonia in acidic urine nonspecific bactericidal action Dose Adults. Hippurate 0.5-1 g bid. Mandelate 1 g qid PO pc hs Peds 6-12 y. Hippurate 25-50 mg/kg/d PO bid. Mandelate 50-75 mg/kg/d PO qid (take w/ food, ascorbic acid w/ adequate hydration) Caution [C, +] Contra Renal insuff, severe hepatic Dz, severe dehydration sulfonamide allergy Disp Tabs SE Rash, GI upset, dysuria, t LFTs EMS Monitor BP for hypovolemia and dehydration OD Sxs unknown symptomatic and supportive... 

Some adverse reactions are unrelated to either allergy or overdose these are termed idiosyncratic. For instance, sulfonamides may precipitate acute hemolysis in some people having a glucose-6-phosphate dehydrogenase dehciency. 

Choquet-Kastylevsky G., T. Vial, and J. Descotes (2002). Allergic adverse reactions to sulfonamides. Current Allergy and Asthma Report 2 16-25. 

Although allergic cross-reactivity with sulfonamide antibiotics and sulfonamide nonantibiotics has not been demonstrated, use with caution in patients with a history of severe sulfa allergies. 

Furosemide Loop diuretic Decreases NaCI and KCI reabsorption in thick ascending limb of the loop of Henle in the nephron (see Chapter 15) Increased excretion of salt and water reduces cardiac preload and afterload reduces pulmonary and peripheral edema Acute and chronic heart failure severe hypertension edematous conditions Oral and IV duration 2-4 h Toxicity Hypovolemia, hypokalemia, orthostatic hypotension, ototoxicity, sulfonamide allergy... 

Hydrochlorothiazide Decreases NaCI reabsorption in the distal convoluted tubule Same as furosemide, but less efficacious Mild chronic failure mild-moderate hypertension hypercalciuria Oral only duration 10-12 h Toxicity Hyponatremia, hypokalemia, hyperglycemia, hyperuricemia, hyperlipidemia, sulfonamide allergy... 

Trimethoprim Oral used only for tower urinary tract infections may be safely prescribed to patients with sulfonamide allergy... 

Darunavir contains a sulfonamide moiety and should be used cautiously in patients with sulfonamide allergy. 

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