Zalcitabine (ddC)

Indications

Zalcitabine (ddC) is used for: Treatment as monotherapy in HIV-infected adults with advanced disease who cannot tolerate Zidovudine or whose disease has progressed despite it; For the treatment of selected patients with advanced AIDS in combination with Zidovudine

Adult Dose

Monotherapy, by mouth, 0.75 mg every 8 hours, given together with 200 mg Zidovudine (Total daily dose is 2.25 mg Zalcitabine and 600 mg Zidovudine); if Zalcitabine is discontinued due to toxicities decrease Zidovudine dose to 100 mg every 4 hours

Child Dose

Safety and efficacy in children less than 13 years of age have not been established.

Renal Dose

Dosage should be adjusted in renal and hepatic impairment

Administration

For Oral use

Contra Indications

Hypersensitivity to Zalcitabine; Avoid in pregnancy

Precautions

Pregnancy-Lactation

Recommendations on the use of Zalcitabine (ddC) in Pregnancy & Lactation: Zalcitabine is classified as FDA category C drug and has been withdrawn from the market because of the associated adverse reactions. Studies in animals have reported significant association with structural abnormalities. There are no adequate and well-controlled studies of its use during pregnancy and lactation (Antiretroviral Pregnancy Registry Steering Committee, 2019; Panel on Treatment of Pregnant Women with HIV Infection and Prevention of Perinatal Transmission, 2020). Recommendation: Zalcitabine is not recommended for use during pregnancy or lactation. References: 1. Antiretroviral Pregnancy Registry Steering Committee. (2019). The antiretroviral pregnancy registry interim report for 1 January 1989 through 31 July 2019. Registry Coordinating Center. www.APRegistry.com 2. Panel on Treatment of Pregnant Women with HIV Infection and Prevention of Perinatal Transmission. (2020). Recommendations for Use of Antiretroviral Drugs in Pregnant women with HIV infection and interventions to reduce perinatal HIV Transmission in the United States. Office of AIDS Research Advisory Council (OARAC). http://aidsinfo.nih.gov/contentfiles/lvguidelines/PerinatalGL.pdf

Interactions

Increased risk of peripheral neuropathy or other toxicities with amphotericin, aminoglycosides, chloramphenicol, cisplatin, dapsone, ethionamide, isoniazid, metronidazole, vincristine, phenytoin, nitrofurantoin

Adverse Effects

Side effects of Zalcitabine (ddC) : Oral ulcers, chest pain, headache, dizziness, myalgia, anaemia, granulocytopenia, skin rash, pruritus, nausea, dysphagia, abdominal pain, vomiting, diarrhoea, body weight reduction, oedema, palpitations, increased heart rate, pancreatitis, hepatic disorders, peripheral neuropathy, tremors, confusion, increased micturition frequency

Mechanism of Action