olsalazine

Absorption: Acts locally in colon, where 98–99% is converted to mesalamine (5-aminosalicylic acid).

Distribution: Action is primarily local and remains in the colon.

Metabolism/Excretion: 2% absorbed into systemic circulation is rapidly metabolized; mostly eliminated as mesalamine in the feces.

Half-Life: 0.9 hr.

Time/Action Profile ⬆ ⬇

(plasma concentrations)

ROUTE	ONSET	PEAK	DURATION
PO	unknown	1 hr; 4–8 hr	12 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity reaction to salicylates;
Cross-sensitivity with furosemide, sulfonylureas, or carbonic anhydrase inhibitors may exist;
Glucose-6-phosphate dehydrogenase (G6PD) deficiency;
Urinary tract or intestinal obstruction;
Porphyria;
Lactation: Lactation.

Use Cautiously in:

Severe hepatic or renal impairment;
Renal impairment (↑ risk of renal tubular damage);
OB: Safety not established in pregnancy;
Pedi: Children 2 yr (safety and effectiveness not established);
Geri: risk of blood dyscrasias (agranulocytosis, neutropenia, pancytopenia) in older adults. Consider hepatic/renal/cardiac function, concomitant illnesses, and drug therapies.

Adv. Reactions/Side Effects ⬆ ⬇

Derm: ACUTE GENERALIZED EXANTHEMATOUS PUSTULOSIS (AGEP), DRUG REACTION WITH EOSINOPHILIA AND SYSTEMIC SYMPTOMS (DRESS), itching, photosensitivity, rash, STEVENS-JOHNSON SYNDROME (SJS), TOXIC EPIDERMAL NECROLYSIS (TEN)

GI: diarrhea, abdominal pain, anorexia, exacerbation of colitis, HEPATOTOXICITY, nausea, vomiting

GU: interstitial nephritis, nephrolithiasis, renal impairment

Hemat: blood dyscrasias

Neuro: ataxia, confusion, depression, dizziness, drowsiness, headache, psychosis, restlessness

Misc: acute intolerance syndrome, hypersensitivity reactions

Interactions ⬆ ⬇

Drug-drug:

↑risk of bleeding after neuraxial anesthesia with low molecular weight heparins and heparin; discontinue olsalazine before initiation of therapy or monitor closely if discontinuation not possible.
May ↑ levels of and risk of bleeding from warfarin; closely monitor INR.
May ↑ myelosuppressive effects of mercaptopurine or azathioprine; avoid concurrent use, if possible.
Concurrent use with NSAIDs may ↑ risk of nephrotoxicity.
↑risk of developing Reye syndrome; avoid olsalazine during 6 wk after varicella vaccine.

Route/Dosage ⬆ ⬇

PO (Adults ): 500 mg twice daily.

Availability ⬆ ⬇

Capsules: 250 mg

Assessment ⬆ ⬇

Assess abdominal pain and frequency, quantity, and consistency of stools at the beginning of and during therapy.
Monitor for hypersensitivity reactions; may present as internal organ involvement (myocarditis, pericarditis, nephritis, hepatitis, pneumonitis, hematologic abnormalities). Discontinue olsalazine if hypersensitivity reactions occur.
Assess patient for allergy to sulfonamides and salicylates. Patients allergic to sulfasalazine may take mesalamine or olsalazine without difficulty, but therapy should be discontinued if rash or fever occur.
Monitor intake and output ratios. Fluid intake should be sufficient to maintain a urine output of ≥1200–1500 mL daily to prevent crystalluria and stone formation.
Assess for severe cutaneous adverse reactions (SJS, TEN, DRESS, and AGEP). Discontinue olsalazine at first sign of severe cutaneous reactions.

Lab Test Considerations:

Monitor urinalysis, BUN, and serum creatinine prior to and periodically during therapy. If renal function declines during therapy, discontinue olsalazine.
- May cause ↑ AST and ALT levels.
Monitor CBC prior to and every 3–6 mo during prolonged therapy. Discontinue olsalazine if blood dyscrasias occur.

Implementation ⬆ ⬇

Maintain adequate hydration during therapy.
PO: Administer with food in evenly divided doses every 12 hr.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take medication as directed, even if feeling better. Take missed doses as soon as remembered unless almost time for next dose.
Inform patient of possible reddish-brown urine discoloration when in contact with surfaces or water treated with hypochlorite-containing bleach.
May cause dizziness. Caution patient to avoid driving or other activities that require alertness until response to medication is known.
Advise patient to notify health care professional if skin rash, sore throat, fever, mouth sores, unusual bleeding or bruising, wheezing, fever, or hives occurs.
Advise patient to avoid sun exposure and to wear sunscreen and protective clothing when outdoors due to ↑risk of photosensitivity reactions.
Instruct patient to notify health care professional if symptoms do not improve after 1–2 mo of therapy.
Instruct patient to notify health care professional if symptoms worsen or do not improve. If symptoms of acute intolerance (cramping, acute abdominal pain, bloody diarrhea, fever, headache, rash) occur, discontinue therapy and notify health care professional immediately.
Rep: Advise females of reproductive potential to use effective contraception and to notify health care professional if pregnancy is planned or suspected and to avoid breastfeeding during therapy. Monitor breastfed infants for diarrhea.
Inform patient that proctoscopy and sigmoidoscopy may be required periodically during treatment to determine response.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇