Pulmonary & Antiviral Pharmacology PDF

 **Most Common Viral Pathogens Associated with Respiratory Tract Infections**: - **Influenza** (A and B), **Respiratory Syncytial Virus** (RSV), **Parainfluenza**, **Rhinovirus**, **Adenovirus**, and **COVID-19** (SARS-CoV-2)​  **Typical Presentation of Viral Respiratory Tract Infectio...

 **Most Common Viral Pathogens Associated with Respiratory Tract Infections**: - **Influenza** (A and B), **Respiratory Syncytial Virus** (RSV), **Parainfluenza**, **Rhinovirus**, **Adenovirus**, and **COVID-19** (SARS-CoV-2)​  **Typical Presentation of Viral Respiratory Tract Infection**: - Symptoms include cough, sneezing, rhinorrhea, sore throat, headache, malaise, and fever​  **Vaccination and Antiviral Treatment**: - **Vaccination**: COVID-19, Influenza, RSV, Varicella (Chickenpox), Shingles, Hepatitis A & B, HPV. - **Antiviral Therapy**: Influenza (Oseltamivir), COVID-19 (Nirmatrelvir/ritonavir for high-risk patients), and RSV (Ribavirin for severe cases)​  **Supportive Care Therapies**: - Hydration, rest, analgesics/antipyretics, humidified air, saline nasal sprays, and hot drinks for sore throat relief​  **Pathophysiology of Viral Pulmonary Infections**: - Viral infections lead to inflammation, causing increased sputum production and cough as the body attempts to clear the airways​  **When Antivirals are Appropriate**: - Antivirals are indicated when they can reduce viral replication early in the course of illness (e.g., within 48 hours for influenza) or for high-risk individuals (e.g., Paxlovid for COVID-19)​  **Symptomatic Management for Cough**: - Dextromethorphan (antitussive), Benzonatate (cough suppressant), Guaifenesin (expectorant), and honey​  **Symptomatic Management for RSV in Pediatric Patients**: - Supportive care, bronchodilators, glucocorticoids, Ribavirin (for severe cases), and monoclonal antibodies like Palivizumab for high-risk infants​  **Prescription for Oral Herpes Simplex Prevention**: - **Valacyclovir**: 1g PO daily or **Acyclovir**: 400 mg PO twice daily​  **Prescription for Oral Herpes Simplex Treatment**: - **Valacyclovir**: 1g PO daily for 7-10 days or **Acyclovir**: 400 mg PO three times daily for 7-10 days​  **Drug Classes for Treating Hepatitis B and C**: - **Hepatitis B**: NRTIs (e.g., Tenofovir, Entecavir), Pegylated Interferon. - **Hepatitis C**: NS5A inhibitors (e.g., Ledipasvir-sofosbuvir, Sofosbuvir-velpatasvir)​ - **Oseltamivir (Tamiflu)** - **Medication Class**: Antiviral Agent; Neuraminidase Inhibitor - **Mechanism of Action**: Inhibits viral neuraminidase, preventing virus release from infected cells - **Indications**: Influenza infection in patients older than two weeks, ideally initiated within 48 hours of symptoms - **Adverse Effects**: Nausea, vomiting, confusion, delirium, hallucinations - **Contraindications**: Infants under two weeks - **Interactions**: Limited known interactions - **Monitoring**: Not generally required - **Patient Education**: Take with food to reduce GI upset; complete the full course even if symptoms improve early​ - **Nirmatrelvir/ritonavir (Paxlovid)** - **Medication Class**: Antiviral Agent; Cytochrome P-450 Inhibitor - **Mechanism of Action**: Inhibits viral replication - **Indications**: COVID-19 infection in high-risk patients, ideally within 72 hours of symptom onset - **Adverse Effects**: Diarrhea, altered taste (dysgeusia) - **Contraindications**: N/A - **Interactions**: Numerous interactions due to CYP450 inhibition; caution with drugs metabolized via CYP3A4 - **Monitoring**: Not generally required - **Patient Education**: Report any unusual side effects, and consult about concurrent medications due to interaction potential​ - **Benzonatate (Tessalon Perles)** - **Medication Class**: Antitussive, Non-narcotic - **Mechanism of Action**: Suppresses cough by anesthetizing respiratory stretch receptors - **Indications**: Symptomatic relief of cough - **Adverse Effects**: Mild GI disturbances, drowsiness - **Contraindications**: Children under 10 years due to risk of choking - **Interactions**: Minimal known interactions - **Monitoring**: None typically required - **Patient Education**: Do not chew or crush; swallow capsules whole to avoid oral mucosal anesthesia​ - **Dextromethorphan** - **Medication Class**: NMDA Receptor Antagonist, Antitussive - **Mechanism of Action**: Reduces cough reflex sensitivity and transmission through medullary cough center depression - **Indications**: Cough suppression - **Adverse Effects**: Drowsiness, dizziness, nervousness, gastrointestinal symptoms - **Contraindications**: Use with or within two weeks of MAOIs; caution in children under two - **Interactions**: SSRIs, MAOIs (risk of serotonin syndrome) - **Monitoring**: None generally needed - **Patient Education**: Avoid driving if drowsy; potential for abuse if taken in high doses​ - **Guaifenesin** - **Medication Class**: Expectorant - **Mechanism of Action**: Thins mucus secretions, aiding expectoration - **Indications**: Chest congestion with productive cough - **Adverse Effects**: Dizziness, drowsiness, headache, nausea - **Contraindications**: Caution in children under two to four years (depends on formulation) - **Interactions**: Avoid with alcohol (ethanol-containing products) - **Monitoring**: None typically required - **Patient Education**: Drink plenty of fluids to assist in mucus thinning; may cause mild GI upset​ - **Acyclovir** - **Medication Class**: Antiviral Agent - **Mechanism of Action**: Inhibits viral DNA synthesis, preventing replication - **Indications**: Herpes simplex, varicella-zoster, and bell palsy - **Adverse Effects**: Renal toxicity (AKI), neurotoxicity, thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS) - **Contraindications**: Caution with renal impairment - **Interactions**: Few significant interactions - **Monitoring**: Renal function in patients with kidney disease - **Patient Education**: Stay hydrated to reduce the risk of kidney side effects​ - **Valacyclovir** - **Medication Class**: Antiviral Agent - **Mechanism of Action**: Converted to acyclovir in the body, then inhibits viral DNA synthesis - **Indications**: Herpes simplex, herpes zoster, and varicella - **Adverse Effects**: Similar to acyclovir (renal toxicity, neurotoxicity, TTP/HUS) - **Contraindications**: Use caution in renal impairment - **Interactions**: Limited significant interactions - **Monitoring**: Kidney function in patients with compromised renal health - **Patient Education**: Hydrate well; take as prescribed for the full course​