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Genotypic testing for Zalcitabine resistance (HIV-associated)

Published: August 9, 2026Updated: August 16, 2026

This test checks whether your HIV virus has developed resistance to the antiviral medication zalcitabine, which may affect how well your treatment works.

Quick summary

["Determining drug resistance helps doctors tailor your HIV treatment plan for better outcomes."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
30285-1
Short code
Zalcitabine Islt Genotyp
Synonyms
Zalcitabine Islt Genotyp
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
genotyping
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What Does This Test Measure?

The test analyzes specific genetic mutations in the HIV virus that could make it resistant to zalcitabine, a nucleoside reverse transcriptase inhibitor (NRTI) used in HIV treatment. It identifies changes in the viral genome that may reduce the drug’s effectiveness.

Why Is This Test Important?

If your virus shows resistance to zalcitabine, your doctor may adjust your treatment to avoid ineffective medications and prevent drug resistance from spreading. This helps ensure your therapy remains effective over time.

How Is the Sample Collected?

A blood sample is typically taken from a vein in your arm. This sample is sent to a lab for genetic analysis to detect mutations linked to zalcitabine resistance.

What Does a Positive Result Mean?

A positive result indicates the presence of genetic mutations in your HIV virus that may reduce zalcitabine’s effectiveness. Your doctor will review the results alongside other clinical factors to guide treatment decisions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Resistance Testing in HIV Treatment

Short name

HIV Drug Resistance Genotyping (Zalcitabine)

Frequently asked questions

How long will I need to wait for results?
Results are usually available within 7 to 14 business days, depending on lab processing times. Your healthcare provider will contact you once they are ready.
Can I stop taking zalcitabine if my test shows resistance?
No, you should not stop taking zalcitabine without consulting your doctor. Resistance testing helps guide treatment adjustments, but your provider will determine the safest and most effective alternative based on your full medical picture.
Does this test require fasting?
No fasting is required for this test. Your blood sample is collected at a convenient time, and no special preparation is needed beyond standard lab procedures.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy