Mismatched double-stranded RNA (ampligen) reduces concentration of zidovudine (azidothymidine) required for in-vitro inhibition of human immunodeficiency virus.

'Ampligen', a non-toxic, mismatched polymer of double-stranded RNA with antiviral and immunomodulatory activities reduced the concentration of zidovudine (azidothymidine, AZT; 'Retrovir', Wellcome) required for inhibitory activity against human immunodeficiency virus (HIV) in vitro. At the higher doses of AZT tested, the virustatic activity observed seemed to have a synergistic virustatic relation with ampligen. Thus, combined therapy with ampligen and AZT can be expected to be more beneficial than AZT alone to patients with the acquired immunodeficiency syndrome (AIDS) or AIDS-related complex since AZT regimens that seem to be clinically effective are associated with considerable toxicity.