Drug Resistance

increased frequency of drug resistances. Neuraminidase inhibitors like those in Tamiflu and Relenza specifically attack influenza viruses by preventing the release of the virus from the host cell, shortening the course of the disease.

HIV disease is treated on the basis of the fact that the virus is a retrovirus, turning its RNA into DNA in the host cell. Drugs to treat these infections include reverse transcriptase inhibitors. There are other antiviral drugs that are called protease inhibitors and integrase inhibitors. Protease inhibitors are used to treat hepatitis C. Integrase inhibitors and fusion inhibitors are also used to treat HIV viral infections. There are other drugs for HIV disease that prevent attachment of the virus to the host cell.

DRUG RESISTANCE

Microbial organisms are always evolving in order to overcome their environment. This leads to drug resistance, made worse by overprescribing of antimicrobials, using the wrong antimicrobial, patient noncompliance, and subtherapeutic dosing. There will be chromosomal mutations that will cause resistance, with the resistance being transferred vertically to the next generations. Plasmids and transposons can also cause drug resistance.

There are four main areas that contribute to drug resistance. The organism can create an efflux pump that pumps the drug out of the cell. Other infectious organisms will have blocked penetration of the drug into the cell. The organism can change its target morphology to be less sensitive to the antimicrobial agent. Still others will inactivate the drug by making a specific enzyme against it.

Beta-lactam resistance and aminoglycoside resistance can occur by the organism making a drug that inactivates the drug. Some organisms will break the beta-lactam ring, inactivating the beta-lactam drug. Rifampin can be inactivated through related mechanisms. Gram-negative organisms will make channels to efflux the drug out of the bacterial cell. Drug resistance to tetracyclines, beta-lactams, and fluoroquinolones can also happen through the formation of efflux pumps. There are many ways to also confer resistance by changing the target of the antibiotic.