Hydroxyurea

Mechanism :

The precise mechanism by which hydroxyurea produces its antineoplastic effects is not known, but it is hypothesised that hydroxyurea causes an immediate inhibition of DNA synthesis, by acting as a ribonucleotide reductase inhibitor, without interfering with the synthesis of ribonucleic acid or of protein. Hydroxyurea probably acts by decreasing the rate of conversion of ribonucleotides and deoxyribonucleotides. This effect is particularly apparent in cells with a high rate of proliferation.

Indication :

• Primary squamous cell carcinomas of the head (except the lip) and neck.
• Resistant chronic myelocytic leukemia
• Melanoma
• To increase HbF in sickle cell anemia

Contraindications :

Contraindicated in patients with marked bone marrow depression, i.e., leukopenia (<2500 WBC/mm) or thrombocytopenia (<100 000/mm, or severe anemia).

Dosing :

Adverse Effect :

Bone marrow depression, maculopapular rash, facial erythema, peripheral erythema, skin ulceration, alopecia, hyperpigmentation, scaling, atrophy of skin and nails, violet papules, erythema, stomatitis, diarrhea, nausea and vomiting, anorexia, constipation, drowsiness, dizziness, headache, hallucinations, disorientation, convulsions, elevated BUN, serum uric acid, and creatinine levels; dysuria, fever with chills, asthenia, malaise, and elevation of hepatic enzymes; diffuse pulmonary infiltrates, dyspnea, infections.

Interaction :

Contraindicated:
Adenovirus vaccine, live; BCG live intravesical; influenza nasal vaccine, live; measles/mumps/rubella vaccine, live; rotavirus vaccine, live; smallpox vaccine (live vaccinia virus); typhoid vaccine, live; varicella vaccine, live; yellow fever vaccine, live;
zoster vaccine, live.
Avoid/Use Alternative:
Alefacept, Belimumab, Clozapine, Deferiprone, Natalizumab, Sipuleucel-T, Thiotepa.
Monitor/Modify Treatment:
Aldesleukin, Alemtuzumab, Altretamine, Azacitidine, Azathioprine, Bendamustine, Brentuximab vedotin, Busulfan, Cabazitaxel, Capecitabine, Carboplatin, Carmustine, Chlorambucil, Cidofovir, Cisplatin, Cladribine, Clofarabine, Cyclophosphamide, Cytarabine, Dacarbazine, Dactinomycin, Dasatinib, Daunorubicin, Decitabine, Dexrazoxane, Didanosine, Docetaxel, Doxorubicin, Epirubicin, Eribulin, Etoposide, Floxuridine, Flucytosine, Fludarabine, Fluorouracil, Ganciclovir, Gemcitabine, Gemtuzumab Ozogamicin, Ibritumomab Tiuxetan, Ibrutinib, Idarubicin, Ifosfamide, Imatinib, Interferon Alfa 2b, Interferon Alfacon-1, Interferon Beta 1a, Irinotecan, Ixabepilone, Lenalidomide, Lomustine, Mechlorethamine, Melphalan, Mercaptopurine, Methotrexate, Mitomycin, Mitoxantrone, Mycophenolate Mofetil, Mycophenolic Acid, Nelarabine, Obinutuzumab, Ofatumumab, Omacetaxine Mepesuccinate, Oxaliplatin, Paclitaxel, Peginterferon Alfa 2a, Peginterferon Alfa 2b, Pentostatin, Pomalidomide, Ponatinib, Pralatrexate, Procarbazine, Pyrimethamine, Radium Ra 223 Dichloride, Ruxolitinib, Stavudine, Temozolomide, Teniposide, Thioguanine, Topotecan, Tositumomab, Valganciclovir, Vinblastine, Vincristine, Vinorelbine, Zidovudine.

Caution Advised:

Abatacept, Adalimumab, Anthrax Vaccine, Belatacept, Cat's Claw, Certolizumab Pegol, Diphtheria/Tetanus And/or Pertussis Vaccine, Echinacea, Etanercept, Fingolimod, Ginseng, Asian, Golimumab, Haemophilus B Conjugate Vaccine, Hepatitis A Vaccine, Hepatitis B Vaccine, Human Papillomavirus Vaccine, Infliximab, Influenza H5N1 Vaccine, (Avian Flu), Influenza Vaccine, Japanese Encephalitis Vaccine, Leflunomide, Melatonin, Meningococcal Vaccine, Pneumococcal Vaccine, Poliovirus Vaccine, Rabies Vaccine, Teriflunomide, Tocilizumab, Tofacitinib, Typhoid Vi Polysaccharide Vaccine, Ustekinumab.

Renal Dose :

Hepatic Dose :