Probenecid

INTRODUCTION

Indications

Prevention of recurrences of gouty arthritis. Treatment of hyperuricemia secondary to thiazide therapy. Used to increase and prolong serum levels of penicillin and related anti-infectives.

Action

Inhibits renal tubular reabsorption of uric acid, thus promoting its renal excretion. Therapeutic Effects: Reduction of serum uric acid levels.

Adverse Reactions/Side Effects

CNS: headache, dizziness. GI: nausea, vomiting, abdominal pain, diarrhea, drug-induced hepatitis, sore gums. GU: uric acid stones, urinary frequency. Derm: flushing, rashes. Hemat: APLASTIC ANEMIA, anemia.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Monitor signs of anemia, including unusual fatigue, shortness of breath with exertion, pallor, and bruising. Notify physician immediately if these signs occur.

• Periodically assess patient's impairments (pain, range of motion), functional ability, and disability to help determine if gout symptoms are reduced by drug therapy.

• Assess dizziness that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician, and caution the patient and family/caregivers to guard against falls and trauma.

Interventions

• Implement appropriate manual therapy techniques, physical agents, therapeutic exercises, and orthotic/assistive devices to reduce pain, improve function, and augment the effects of antigout drug therapy.

Patient/Client-Related Instruction

• Advise patient about the likelihood of GI reactions such as nausea, vomiting, diarrhea, abdominal pain, and sore gums. Instruct patient to report severe or prolonged GI problems or signs of drug-induced hepatitis (yellow skin or eyes, abdominal pain, severe nausea and vomiting, fever, sore throat, malaise, weakness, facial edema).

• Instruct patient to report other untoward side effects such as severe or prolonged headache, urinary frequency, pain associated with kidney stones, or skin reactions (rash, flushing).

Pharmacokinetics

Absorption: Well absorbed following oral administration.

Distribution: Crosses the placenta.

Protein Binding: 75–95%.

Metabolism and Excretion: Mostly metabolized by the liver; 10% excreted unchanged in the urine.

Half-life: 4–17 hr.

Contraindications/Precautions

Contraindicated in: Hypersensitivity; Chronic high-dose salicylate therapy; Children <2 yr.

Use Cautiously in: Peptic ulcer; Blood dyscrasias; Uric acid kidney stones; Renal impairment (dosage reduction recommended; may not be effective if CCr ≤30 mL/min); Pregnancy or lactation (has been used safely during pregnancy; safety during lactation not established).

Interactions

Drug-Drug: ↑ ...