Antiretroviral Agents

Antiretroviral Drugs Overview

Introduction to Antiretroviral Drugs

• The lecture focuses on antiretroviral drugs, emphasizing the importance of understanding the HIV life cycle prior to this discussion.

• Students are encouraged to watch introductory videos on HIV for better comprehension of drug classifications.

Understanding HIV and Drug Classifications

• Human Immunodeficiency Virus (HIV) attaches to CD4 receptors and CCR5, initiating its life cycle.

• The lecture introduces Highly Active Antiretroviral Therapy (HAART), which combines at least three antiviral drugs targeting various stages of the HIV life cycle for maximum effectiveness with minimal toxicity.

Types of Antiretroviral Drugs

Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs)

• NNRTIs directly affect HIV activity by binding to reverse transcriptase, blocking RNA and DNA-dependent polymerase activity, making replication impossible.

• Indicated for patients with documented AIDS or AIDS-related complex (ARC), especially those experiencing opportunistic infections despite other treatments.

Nucleoside Reverse Transcriptase Inhibitors (NRTIs)

• NRTIs were the first class developed for treating HIV; they compete with natural nucleosides needed by the virus to replicate within human cells.

• They can be used in combination therapy for adults and children with HIV and also prevent maternal transmission during childbirth.

Contraindications and Adverse Effects

NNRTIs

• Contraindicated in pregnancy unless benefits outweigh risks; safety in children is not established. Common adverse effects include dizziness, blurred vision, headache, gastrointestinal issues like dry mouth, constipation, nausea, abdominal pain, and flu-like symptoms. Monitoring is essential due to potential electrolyte imbalances from diarrhea or vomiting.

NRTIs

Understanding HIV Treatment: Key Concepts and Medications

Patient Education on Fat Distribution

• Educate patients about the distribution of fat loss from arms, legs, and face, as well as the repositioning of fat on the trunk, neck, and face.

Protease Inhibitors Overview

• Protease inhibitors render the virus immature and non-infective by blocking protease essential for viral maturation. This is crucial in HIV treatment.

• Indicated for combination therapy in treating HIV infections; at least three different combinations are necessary for effective management.

Contraindications and Cautions

• General contraindications include pregnancy and lactation; while some protease inhibitors are not teratogenic, they can cross into breast milk. Monitor hepatic function due to increased toxicity risks with certain drugs like fosamprenavir.

• Patients on anti-diabetic medications should be monitored closely as some protease inhibitors may cause diabetes mellitus or hyperglycemia.

Adverse Reactions to Watch For

• Common adverse effects include nausea, vomiting, diarrhea, changes in liver function, elevated cholesterol/triglycerides, and potential dermatological reactions such as Stevens-Johnson syndrome. Monitoring skin care is advised for patients experiencing rashes.

Fusion Inhibitors Introduction

• Introduced in 2003; fusion inhibitors prevent HIV from entering human cells by blocking its fusion with cellular membranes. They are indicated for adults and children over six years old who show evidence of ongoing replication despite antiretroviral therapy.

CCR5 Antagonists Explained

• CCR5 antagonists block receptor sites needed for HIV interaction with cells; introduced in 2007 as part of combination therapy with other antiviral agents. Contraindications include pregnancy/lactation and hypersensitivity to drugs. Safety in children has not been established yet due to maternal transmission concerns during pregnancy.

Integrase Inhibitors Functionality

• Released in late 2007; integrase inhibitors block an enzyme critical for viral replication (integrase), leading to decreased viral load and improved immune response among treated patients who have previously undergone antiviral treatments but still experience replication issues. Caution is advised regarding rhabdomyolysis risk during pregnancy or muscle injury scenarios.

Monitoring Adverse Effects

Antiretroviral Therapy and Its Effects

Adverse Effects of Antiretroviral Therapy

• Diarrhea in patients can be attributed to antiretroviral therapy, indicating a significant adverse effect associated with these medications.

• Gastroenteritis is mentioned as a common infectious process affecting patients undergoing antiretroviral treatment, highlighting the need for careful monitoring.

• The use of antiretroviral agents is not recommended during pregnancy due to potential risks, emphasizing the importance of considering maternal health and fetal safety.

• Women of childbearing age are encouraged to utilize non-contraceptive measures to prevent toxic effects on the fetus from antiretroviral drugs.

Recommendations for Breastfeeding Mothers