Zalcitabine( Dideoxycytidine ; ddC )
Class: Nucleoside reverse transcriptase inhibitor
- Tablets 0.375 mg
- Tablets 0.75 mg
Inhibits replication of DNA in HIV.
Oral bioavailability is about 80%. Absorption rate of a 1.5 mg oral dose was reduced with food. C max is 25.2 ng/mL. T max is 0.8 h. AUC is 72 ng•h/mL.
Vd is 0.534 L/kg. Less than 4% protein bound. Drug interaction involved in binding site is unlikely.
Major metabolite is dideoxyuridine.
Renal elimination is the primary route of elimination. The t ½ is about 2 h.
Special PopulationsRenal Function Impairment
Prolonged elimination may be expected.Children
Mean bioavailability is 54%.
Indications and UsageCombination therapy
For the treatment of selected patients with advanced HIV infection.
Dosage and AdministrationCombination therapy
Adults and Adolescents more than 13 yr
PO 0.75 mg (coadministered with other antiviral agents) every 8 h (total daily dose 2.25 mg zalcitabine).
Store at room temperature in tight containers.
Drug InteractionsAminoglycosides, amphotericin, foscarnet
May increase risk of peripheral neuropathy and other zalcitabine toxicities caused by decreased clearance of zalcitabine.Chloramphenicol, cisplatin, dapsone, disulfiram, ethionamide, glutethimide, gold, hydralazine, iodoquinol, isoniazid, metronidazole, nitrofurantoin, phenytoin, ribavirin, vincristine
May increase risk of peripheral neuropathy.Drugs associated with pancreatitis (eg, pentamidine)
Fatal pancreatitis has occurred, possibly related to zalcitabine and IV pentamidine given concurrently.
Laboratory Test Interactions
None well documented.
Chest pain; cardiomyopathy; CHF.
Headache; dizziness; confusion; impaired concentration; peripheral neuropathy.
Rash; pruritus; dermatitis.
Pancreatitis; oral ulcers; nausea; dysphagia; anorexia; abdominal pain; vomiting; diarrhea; dry mouth; esophageal ulcers; dyspepsia; glossitis.
Weight decrease; weight gain; increased amylase; hyperglycemia; hyponatremia; hypoglycemia; loss of appetite.
Nasal discharge; cough; respiratory distress.
Myalgia; arthralgia; foot pain; fatigue; anaphylactoid reaction; abnormal GGT.
Hepatic failure and death, possibly related to underlying hepatitis B and zalcitabine, have been reported.Lactic acidosis and hepatomegaly
Have been reported with steatosis (including fatal cases) reported with the use of nucleoside analogues alone or in combination with other antiretrovirals.Neuropathy
Severe peripheral neuropathy, use with extreme caution in patients with preexisting neuropathy.Pancreatitis
Rarely occurs; monitor.
Category C .
Undetermined. It is recommended that HIV-positive women do not breast-feed.
Safety and efficacy in children less than 13 yr not established.
Patients with renal impairment (CrCl less than 55 mL/min) may be at greater risk of toxicity because of decreased drug clearance. Dosage reduction may be needed.
In patients with history of liver disease or alcoholism, zalcitabine may exacerbate hepatic dysfunction. Dosage reduction or interruption of therapy may be needed.
Anaphylactoid reaction has occurred. Urticaria has occurred without other signs of anaphylaxis.
Cardiomyopathy/CHF may develop. Use drug with caution in patients with history of cardiomyopathy or CHF.
Esophageal ulcers have occurred.
HIV infection complications
Patients receiving zalcitabine or any other antiretroviral therapy may continue to develop opportunistic infections and other complications of HIV infection.
Rash, fever, peripheral neuropathy.
- Advise patient to take around the clock as prescribed and not to increase the dose.
- Advise patient not to share the drug with others.
- Inform patient and family that patient may continue to develop opportunistic infections and other complications of HIV infection and should remain under close medical supervision.
- Explain that zalcitabine is not a cure but may offer symptomatic improvement.
- Reinforce fact that zalcitabine does not decrease risk of transmission of HIV through sexual contact or blood contamination.
- Instruct patient to notify health care provider immediately of signs of peripheral neuropathy (numbness and burning feeling in arms and legs) or pancreatitis (abdominal pain, nausea, vomiting).
- Encourage patient to report all changes in conditions to health care provider.
- Inform patient that long-term effects of this drug alone and in combination with zidovudine are unknown.
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