Zidovudine

How it works

As a thymidine analogue it is phosphorylated intracellularly and incorporated into viral DNA, inhibiting HIV reverse transcriptase and terminating the growing DNA chain.

Prescribing in practice

• It can cause serious bone-marrow suppression with anaemia and neutropenia, and rarely lactic acidosis with hepatic steatosis, so the full blood count and clinical status must be monitored.
• It must always be used within a combination antiretroviral regimen and never as monotherapy outside specific perinatal prophylaxis contexts.
• Concurrent use with other myelosuppressive or marrow-toxic drugs increases haematological risk and should be reviewed against current prescribing references.

Monitoring

Monitor the full blood count regularly, along with HIV viral load and CD4 count and liver function, as guided by specialist HIV care.

Counselling the patient

• Take every dose exactly as prescribed to keep the virus suppressed and reduce resistance.
• Report unusual tiredness, breathlessness, or signs of infection promptly.
• Do not stop or change your other HIV medicines without specialist advice.

Evidence & guidelines

Its role is established by historical landmark antiretroviral trials and current British HIV Association treatment guidance.