Question

JPlease discuss ONE SPECIFIC medication for Sexually Transmitted Disease. Give class; actions and uses; side effects & adverse reactions; contraindications & toxicity; administration; any other pertinent information.

Answer 1

HIV infection starts when the virus is transmitted through contact with infected body fluids, such as blood, semen, or breast milk. HIV targets the immune system and invades white blood cells called T-cells. These are cells that fight infection. By entering the body’s cells, the virus hides from the immune system.

There's no cure for HIV/AIDS, but many different drugs are available to control the virus. Such treatment is called antiretroviral therapy, or ART. Each class of drug blocks the virus in different ways. ART is now recommended for everyone, regardless of CD4 T cell counts. It's recommended to combine three drugs from two classes to avoid creating drug-resistant strains of HIV.

The classes of anti-HIV drugs include:

• Non-nucleoside reverse transcriptase inhibitors (NNRTIs) turn off a protein needed by HIV to make copies of itself. Examples include efavirenz (Sustiva), etravirine (Intelence) and nevirapine (Viramune).
• Nucleoside or nucleotide reverse transcriptase inhibitors (NRTIs) are faulty versions of the building blocks that HIV needs to make copies of itself. Examples include Abacavir (Ziagen), and the combination drugs emtricitabine/tenofovir (Truvada), Descovy (tenofovir alafenamide/emtricitabine), and lamivudine-zidovudine (Combivir).
• Protease inhibitors (PIs) inactivate HIV protease, another protein that HIV needs to make copies of itself. Examples include atazanavir (Reyataz), darunavir (Prezista), fosamprenavir (Lexiva) and indinavir (Crixivan).
• Entry or fusion inhibitors Tblock HIV's entry into CD4 T cells. Examples include enfuvirtide (Fuzeon) and maraviroc (Selzentry).
• Integrase inhibitors work by disabling a protein called integrase, which HIV uses to insert its genetic material into CD4 T cells. Examples include raltegravir (Isentress) and dolutegravir (Tivicay)  
• Efavirenz (EFV), sold under the brand names Sustiva among others, is an antiretroviral medication used to treat and prevent HIV/AIDS
• class-

  Class:

  Efavirenz is a benzoxamine compound.

  Antiviral Activity:

  Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are highly selective for HIV-1 but do not exhibit activity against other viruses.

  Mechanism of Action:

  NNRTIs bind noncompetitively to an active site of the reverse transcriptase molecule. Reverse transcriptase directs the polymerization of DNA from viral RNA. The NNRTIs inhibit this polymerization by altering the position of critical amino acids within the catalytic site.

  Mechanism of Resistance:

  Resistance of NNRTIs occurs through mutations of the reverse transcriptase gene in the viral genome. When nonnucleoside reverse transcriptase inhibitors are used as monotherapy for HIV-1 infection, drug resistance develops rapidly. NNRTI naïve patients with prior nucleoside analogue reverse transcriptase inhibitor (NRTI) exposure, who have isolates with resistance mutations and phenotypic resistance to NRTIs, appear more likely to have hypersusceptibility to the NNRTI class of drugs.

• Adverse Effects:

  The most common adverse effects with efavirenz therapy are central nervous system symptoms, rash and hepatitis.

  Dosage:

  Capsule – 50mg (90 capsule bottle), 100mg (90 capsule bottle), 200mg (90 capsule bottle)

  Tablet – 600mg (30 tablet bottle)

  Adult dosing:

  600 mg daily

  Pediatric Dosing:

  10 kg to < 15 kg – 200mg daily

  15 kg to < 20 kg – 250mg daily

  20 kg to < 25 kg – 300mg daily

  25 kg to < 32.5 kg – 350mg daily

  32.5 kg to < 40 kg – 400mg daily

  > 40 kg – 600mg daily

  Take on an empty stomach preferably at night

  Disease state based dosing:

  Dose adjustments in renal dysfunction do not appear to be necessary.

  Use with caution in patients with impaired hepatic function.

  Contraindications/Warnings/Precautions:

  Do not give in combination with agents that are highly dependent on metabolism through CYP450 3A4.

  Do not give during pregnancy due to the risk of fetal malformations.

  Drug Interactions:

  Efavirenz is principally metabolized by CYP450 2B6 and 3A4 to hydroxylated metabolites with subsequent glucuronidation. In vitro, efavirenz is an inhibitor of CYP3A4, CYP2C9, and CYP2C19. However, its effect on CYP3A4 is mixed, as it has also been shown to induce this enzyme. Therefore, medications that are metabolized through CYP2B6, 3A4, 2C9 and 2C19 as well as those that glucuronidated may interact with efavirenz.

  Pregnancy:

  Category D: Risk established, but benefits may outweigh risk.

  Efavirenz has demonstrated rodent teratogenicity and caused malformations in 3 of 20 fetal cynomolgous monkeys. These malformations included anencephaly, anophthalmia and microphthalmia. Therefore, efavirenz should not be administered during pregnancy.

  Monitoring Requirements:

  NNRTIs are suitable for TDM for several reasons, including considerable interpatient variability in concentrations among patients who take the same dose and data indicating relationships between the concentration of drug in the body, the anti-HIV effect and in some cases, toxicity.

  Liver function tests, cholesterol and triglycerides should be monitored in patients taking efavirenz.

  Brand names/Manufacturer:

  Sustiva®