Abstract This paper aims at describing the Maraviroc drug that is approved by the FDA. Besides that, the paper is aimed at analyzing how the drug physiologically operates or works based on the mechanisms of human biology. The paper will cover how the mechanisms correspond to the biological activity, side effects, utility, and the experience with HIV aids patients. To manage a drug, one has to consider the patients’ outcomes and response toward the drug. Again, the drug itself has to be managed to achieve its intended goal. Therefore, the drug must be monitored closely in the market in order to investigate any adverse reactions or resistance. FDA Food and drugs administration is a body that scientifically endorses the usage of a given drug to cure human diseases. This drug must be approved before being released to the market. Besides that, this body closely monitors the welfare of that drug in the market and its side effects. Maraviroc (Selzentry) got FDA approval in 2007 for the healing or suppressing of CCR5-tropic HIV-1. This approval was prescribed for the experienced adult patients. Maraviroc is prescribed and can be used together with other antiretroviral treatments. However, Maraviroc does not heal HIV aids. Besides that, it does not stop the spread and contamination of the virus to healthy individuals. HIV Virus HIV is a virus that is composed of RNA molecules, the enzyme, and has got the reverse transcriptase enzyme that enables it to change its mechanism of replication. This virus cannot replicate or multiply unless it enters into the DNA of another organism. In order for this virus to replicate, it must seek shelter in the human host CD4 cell. In the host CD4 cells the virus implant itself into the first receptor which is the surface of the CD4 cell and then into the second receptor. This second receptor is either CCR5 or CXCR4. However, at the beginning of infections, most HIV strains use CCR5.   * Patient Version: Selzentry (Maraviroc)   * Brand Name: Selzentry   * Generic Name: Maraviroc   * Drug Class: Entry and Fusion Inhibitors (CCR5 antagonist) Introduction This FDA body has approved many drugs in connection to prevention, treatment, and curing of various diseases infecting or affecting human beings. Some of these drugs include Aptivus (tipranavir) and Selzentry (maraviroc) for HIV aids among others. For my part, I have decided to choose Selzentry which is also marketed as Celsentri outside the USA. This drug is an entry competitive inhibitor that fuses with the cells in order to inhibit the infected cells from affecting other cells. Therefore, it is used to suppress HIV aids in human beings or to slow down the process of infection but it does not fully cure the disease. Maraviroc is an antiretroviral drug for adults (with CCR5-tropic HIV-1). Before I address the management, dosage, and side effects of maraviroc, it is good to understand the mechanism, pharmacology, and how the CD4 cells are affected by the HIV virus. After that, the mechanism of how maraviroc works will be understood. The immune system in the body is facilitated by the blood. In the blood, there are the erythrocytes and leukocytes/lymphocytes. Leucocytes are the white blood cells that defen