Effect of stage of disease and drug dose on zidovudine susceptibilities of isolates of human immunodeficiency virus

Article Abstract:

Viruses that replicate within human cells undergo a sort of evolution in miniature, in which variation occurs naturally, and those variants which are more suitable, or fittest, are also those more likely to survive and replicate again. The same is true of the AIDS virus. In the presence of a drug such as zidovudine, the majority of viruses will be inhibited in their replication. Should a mutation accidentally create a variant, which is resistant to zidovudine, this new virus would have a tremendous advantage over other mutations, and would be much more likely to survive and replicate. Over time, most of the viruses recovered from a patient would turn out to be resistant to zidovudine. Such development of drug resistance can be observed in patients with AIDS. Indeed, strains of virus emerge that are so resistant that they can tolerate higher doses of zidovudine in tissue culture dishes than can ever be attained within a human body. To further examine the development of zidovudine resistance among HIV-infected individuals and AIDS patients, HIV specimens were recovered from 73 patients. The susceptibility of the specimens to zidovudine was tested in tissue culture and correlated with the stage of disease and the dosage of zidovudine received by the patient. The results revealed that zidovudine resistance increased most rapidly in the later stages of the disease. This is not unexpected since in later stages more virus replication occurs and, thus, more chances for resistant mutations. The study also found that patients who received lower doses of zidovudine were not more likely to develop drug resistance. (In the case of bacteria, lower doses of antibiotics often permit the survival of marginally resistant strains, which serve as parents to possible future generations of super-resistant strains of bacteria.) Among the HIV specimens obtained from 17 patients who had not received zidovudine at all, there was no observed drug resistance. However, it is impossible to say whether, among the multitude of nonresistant viruses, there were not a few resistant viruses hidden in the crowd. (Consumer Summary produced by Reliance Medical Information, Inc.)

Evaluation, HIV (Viruses), HIV, Genetic aspects, Drug resistance in microorganisms, Microbial drug resistance, AIDS (Disease), Microbial mutation

---

Peripheral nerve function in persons with asymptomatic or minimally symptomatic HIV disease: absence of zidovudine neurotoxicity

Article Abstract:

Zidovudine (ZDV) is used to prolong survival of patients with AIDS and slow the development of HIV (human immunodeficiency virus) infection to AIDS. ZDV is a nucleoside that is incorporated into the nucleic acid (the genetic material) of the virus and inhibits viral replication. Nucleosides have been shown to cause neuropathies (abnormalities in the function of peripheral nerves, which innervate the extremities). However, ZDV has been shown to cause improvement of the type of neuropathies that commonly occur among patients with advanced HIV disease. Subtle neuropathic effects of ZDV were examined in patients with early HIV infection who had mild symptoms of the disease or were asymptomatic. The functions of the peripheral nerves were examined in patients who had received ZDV for an average of 52 weeks. The results were compared with those of control patients not receiving the drug. Abnormalities of nerve function were seen in fewer than 10 percent of the subjects in each group. Reflexes were depressed in approximately the same number of patients in the ZDV and control groups. No differences were seen in sensory testing for vibration in the two groups. Thus, ZDV treatment did not cause the development of peripheral nerve abnormalities in patients with early HIV infection who tend to have a low incidence of peripheral nerve abnormalities. (Consumer Summary produced by Reliance Medical Information, Inc.)

Complications and side effects, HIV infection, HIV infections, Nerves, Peripheral, Peripheral nerves

---

Similar abstracts:

• Abstracts: A pilot study of low-dose zidovudine in human immunodeficiency virus infection. Plasma viremia in human immunodeficiency virus infection
• Abstracts: Natural history and serologic diagnosis of infants born to human immunodeficiency virus-infected women. The human immunodeficiency virus-infected infant
• Abstracts: A pilot study of low-dose zidovudine in human immunodeficiency virus infection. part 2 Recovery of human immunodeficiency virus type 1 from semen: minimal impact of stage of infection and current antiviral chemotherapy
• Abstracts: Partner notification and the control of human immunodeficiency virus infection. Kaposi's sarcoma reporting in San Francisco: a comparison of AIDS and cancer surveillance systems
• Abstracts: Screening of selected male blood donors for p24 antigen of human immunodeficiency virus type 1. Long-term mortality after transfusion-associated non-A, non-B hepatitis

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.