Pharmacology 3620 Lecture Notes - Lecture 44: Entry Inhibitor, Vidarabine, Aciclovir
Document Summary
Intracellular parasites i. e. not able to replicate on their own; must hijack host cell machinery. Dna or rna enclosed in a protein coat (capsid) Proteins are enzymes necessary for viral replication, which function with the cell"s own enzymes to make more virions. Therapeutic strategies: inhibition of virus-specific replicative events or virus-directed, rather than host cell- directed, nucleic acid or protein synthesis. Therapy against viruses is difficult as symptoms often appear late (i. e. when replication has occurred and lots of virions are present) Many antiviral compounds are too toxic for humans (i. e. narrow therapeutic window: even when there is a reasonable therapeutic window, viruses mutate frequently because they do not have dna-repair enzymes. Single-nucleotide (amino acid substitutions) in viral enzymes occur easily and result in resistance. Dna-containing viruses: proteins on cell membrane must recognize viral membrane and allow attachment and entrance into mammalian. Most drugs treat viruses by influencing transcription, dna polymerases, and viral neuraminidase.