This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti-HIV Drugs, Subject name: Pharmacology
Which of the following drugs is most likely to cause additive anemia and neutropenia if administered to an AIDS patient taking zidovudine? 
Select and explain. 
A. Acyclovir, B. Amantadine, C. Ganciclovir, D. Stavudine
C: Ganciclovir
Answer: C: Ganciclovir 
Explanation: * Ganciclovir is the drug of choice for CMV infections. * It should not be combined with zidovudine because both have bone marrow suppressant propey. * It is an analogue of acyclovir which is most active against CMV. but also inhibits other herpes viruses viz. H.simplex, H. zoster and EBV.