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Sulfisoxazole and Phenazopyridine
Pronunciation
Generic Available
Synonyms
Pharmacological Index
Use
Pregnancy Risk Factor
Contraindications
Adverse Reactions
Drug Interactions
Mechanism of Action
Pharmacodynamics/Kinetics
Usual Dosage
Dietary Considerations
Administration
Mental Health: Effects on Mental Status
Mental Health: Effects on Psychiatric Treatment
Dental Health: Local Anesthetic/Vasoconstrictor Precautions
Dental Health: Effects on Dental Treatment
Patient Information
Nursing Implications
Dosage Forms

Pronunciation
(sul fi SOKS a zole & fen az oh PEER i deen)

Generic Available

Yes


Synonyms
Phenazopyridine and Sulfisoxazole

Pharmacological Index

Antibiotic, Sulfonamide Derivative; Local Anesthetic


Use

Treatment of urinary tract infections and nocardiosis


Pregnancy Risk Factor

B/D (at term)


Contraindications

Porphyria; hypersensitivity to any sulfa drug or any component; pregnancy at term; children <2 months of age unless indicated for the treatment of congenital toxoplasmosis; sunscreens containing PABA


Adverse Reactions

>10%:

Central nervous system: Fever, dizziness, headache

Dermatologic: Itching, rash, photosensitivity

Gastrointestinal: Anorexia, nausea, vomiting, diarrhea

1% to 10%:

Dermatologic: Lyell's syndrome, Stevens-Johnson syndrome

Hematologic: Granulocytopenia, leukopenia, thrombocytopenia, aplastic anemia, hemolytic anemia

Hepatic: Hepatitis


Drug Interactions

Decreased effect with PABA or PABA metabolites of drugs (ie, procaine, proparacaine, tetracaine); cyclosporine levels may be decreased

Increased effect/toxicity of oral anticoagulants, oral hypoglycemic agents, hydantoins, uricosuric agents, methotrexate when administered with sulfonamides

Increased toxicity of sulfonamides with diuretics, indomethacin, methenamine, probenecid, and salicylates


Mechanism of Action

Interferes with bacterial growth by inhibiting bacterial folic acid synthesis through competitive antagonism of PABA; phenazopyridine exerts local anesthetic or analgesic action on urinary tract mucosa through an unknown mechanism


Pharmacodynamics/Kinetics

Absorption: Sulfisoxazole acetyl is hydrolyzed in the GI tract to sulfisoxazole which is readily absorbed

Serum half-life: 4-7 hours, prolonged with renal impairment

Time to peak serum concentration: Within 2-3 hours


Usual Dosage

Adults: Oral: 4-6 tablets to start, then 2 tablets 4 times/day for 2 days, then continue with sulfisoxazole only


Dietary Considerations

Should be administered 1 hour before or 2 hours after a meal on an empty stomach


Administration

Administer around-the-clock rather than 4 times/day to promote less variation in peak and trough serum levels


Mental Health: Effects on Mental Status

Dizziness is common; sulfonamides reported to cause restlessness, irritability, depression, euphoria, disorientation, panic, hallucinations, and delusions


Mental Health: Effects on Psychiatric Treatment

Photosensitivity is common; use caution with concurrent psychotropics; may cause leukopenia; caution with clozapine and carbamazepine


Dental Health: Local Anesthetic/Vasoconstrictor Precautions

No information available to require special precautions


Dental Health: Effects on Dental Treatment

No effects or complications reported


Patient Information

See individual agents. Pregnancy/breast-feeding precautions: Inform prescriber if you are or intend to get pregnant. Consult prescriber if breast-feeding.


Nursing Implications

May cause reddish-orange discoloration of urine; staining of contact lenses has also been reported; drink plenty of fluids; administer on an empty stomach; avoid prolonged exposure to sunlight or wear protective clothing and sunscreen; notify physician if rash, difficulty breathing, severe or persistent fever, or sore throat occurs


Dosage Forms

Tablet: Sulfisoxazole 500 mg and phenazopyridine 50 mg


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