Hydroxyurea

INTRODUCTION

Indications

Treatment of head and neck carcinoma. Treatment of ovarian carcinoma. Treatment of resistant chronic myelogenous leukemia. Treatment of melanoma. Reduction of painful crises in sickle cell anemia and decreased need for transfusions in adult patients with a history of recurrent moderate-to-severe crises (at least 3 in the preceding year). Unlabeled Use: Used as part of antiretroviral therapy in patients with HIV infection.

Action

Interferes with DNA synthesis (cell-cycle S-phase–specific). May alter characteristics of RBCs. Therapeutic Effects: Death of rapidly replicating cells, particularly malignant ones. Decreased frequency of painful crises and decreased need for transfusions in sickle cell anemia.

Adverse Reactions/Side Effects

CNS: drowsiness (large doses). GI: anorexia, diarrhea, nausea, vomiting, constipation, hepatitis, stomatitis. GU: dysuria, infertility, renal tubular dysfunction. Derm: alopecia, exacerbation of postradiation erythema, erythema, pruritus, rashes. Hemat: leukopenia, anemia, thrombocytopenia. Metab: hyperuricemia. Misc: chills, fever, malaise.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Be alert for signs of leukopenia (fever, sore throat, signs of infection), thrombocytopenia (bruising, nose bleeds, bleeding gums), or unusual weakness and fatigue that might be due to anemia or other blood dyscrasias. Report these signs immediately to the physician or nursing staff.

• Assess drowsiness that might affect gait, balance, and other functional activities. Notify physician, nursing staff, and family/caregivers if drowsiness becomes problematic.

Interventions

• For patients who are medically able to begin exercise, implement appropriate resistive exercises and aerobic training to maintain muscle strength and aerobic capacity during cancer chemotherapy or to help restore function after chemotherapy.

• If treating patients with sickle-cell anemia, use caution during aerobic exercise and other forms of therapeutic exercise. Assess exercise tolerance frequently (blood pressure, heart rate, fatigue levels), and terminate exercise immediately if any untoward responses occur (See Appendix L).

Patient/Client-Related Instruction

• Advise patient to guard against infection (frequent hand washing, etc.), and to avoid crowds and contact with persons with contagious diseases.

• Advise patient that rashes and other skin reactions (itching, hair loss, redness, warmth) are likely. Severe or unexpected skin reactions should be reported to the physician.

• Advise patient about the likelihood of GI reactions such as diarrhea, nausea, vomiting, constipation, loss of appetite, and inflammation in/around the mouth. Instruct patient to report severe or prolonged GI problems, or signs of drug-induced hepatitis, including abdominal pain, severe nausea and vomiting, yellow skin or eyes, skin rashes, and muscle/joint pain.

• Advise patient that flu-like symptoms (fever, chills, body aches) are likely, and to report severe or prolonged symptoms.

• Instruct patient to report any urinary problems, including difficult or painful urination.

Pharmacokinetics