What is the process for taking a reliable medical history, and what are the uses, mechanisms of action, and side effects of various medications, including Anti-hypertensives, Antibiotics, Anti-viral (Antiretroviral drugs), Analgesics, and Antihistamines, and how are calculations performed for medication administration, such as for Furosemide (Lasix), Dilantin (Phenytoin), and Ceftin (Cefuroxime), and what is the Intravenous (IV) flow rate for 0.5% dextrose?

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From the Guidelines

Taking a reliable medical history involves establishing rapport with the patient, using open-ended questions followed by specific inquiries, and systematically covering chief complaints, present illness, past medical history, family history, social history, and medication history, as emphasized by the importance of accurate medication histories in preventing errors 1.

Medication Classes and Their Mechanisms

  • Anti-hypertensives work through various mechanisms to lower blood pressure, including:
    • ACE inhibitors like lisinopril, which block angiotensin conversion and may cause cough.
    • Beta-blockers such as metoprolol, which reduce heart rate and contractility but can cause fatigue.
    • Calcium channel blockers like amlodipine, which relax blood vessels but may cause edema.
    • Diuretics such as hydrochlorothiazide, which increase urine output but can affect electrolytes.
  • Antibiotics target bacterial infections through different mechanisms, including:
    • Penicillins (amoxicillin), which inhibit cell wall synthesis and may cause allergic reactions.
    • Macrolides (azithromycin), which inhibit protein synthesis and can cause GI disturbances.
    • Fluoroquinolones (ciprofloxacin), which inhibit DNA gyrase but may affect tendons.
    • Tetracyclines (doxycycline), which block protein synthesis and can cause photosensitivity.
  • Antiretrovirals combat HIV through various mechanisms, including:
    • NRTIs like tenofovir, which inhibit reverse transcriptase.
    • NNRTIs such as efavirenz, which also target reverse transcriptase differently.
    • Protease inhibitors like darunavir, which block viral assembly.
    • Integrase inhibitors such as dolutegravir, which prevent viral DNA integration, with side effects including metabolic changes, neuropathy, and hepatotoxicity.
  • Analgesics relieve pain through different pathways, including:
    • NSAIDs like ibuprofen, which inhibit prostaglandin synthesis but can cause GI bleeding.
    • Acetaminophen, which works centrally with hepatotoxicity risk.
    • Opioids like morphine, which bind to receptors but risk respiratory depression and dependence.
    • COX-2 inhibitors like celecoxib, which have fewer GI effects but cardiovascular concerns.
  • Antihistamines block histamine receptors, with:
    • First-generation (diphenhydramine) crossing the blood-brain barrier and causing sedation.
    • Second-generation (cetirizine) being less sedating, treating allergies but potentially causing dry mouth, urinary retention, and drowsiness.

Medication Administration Calculations

  • For Furosemide 10mg, 0.25ml is required (10mg ÷ 40mg/ml = 0.25ml).
  • For Dilantin-125,0.3g equals 300mg, requiring 12ml (300mg ÷ 125mg × 5ml = 12ml).
  • The IV flow rate for 250ml over 180 minutes is 42 drops/minute (250ml ÷ 180min × 30gtts/ml = 41.67, rounded to 42).
  • For the infant weighing 20.5lb (9.3kg), the prescribed dose of 250mg every 8 hours (750mg/day) exceeds the recommended range of 698-1395mg/day (75-150mg/kg/day × 9.3kg), making it appropriate, as per guidelines for pediatric antihypertensive medication dosing 1.

Recent Guidelines on Hypertension Management

The 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults recommends the use of thiazide diuretics, ACE inhibitors, ARBs, and CCBs as primary agents for the treatment of hypertension, due to their proven ability to reduce clinical events 1. This approach prioritizes the reduction of morbidity, mortality, and improvement of quality of life for patients with hypertension.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Process for Taking a Reliable Medical History

The process for taking a reliable medical history involves a structured but flexible approach to gathering relevant information from patients to inform diagnosis and treatment 2, 3, 4. This includes:

  • Preparing the environment for history taking
  • Using effective communication skills, such as active listening, empathetic communication, and cultural sensitivity 2, 5
  • Understanding the levels of health history, including comprehensive, detail-limited, and challenging health histories 4
  • Using a data collection guide to improve accuracy of health histories 4

Medications and Their Uses, Mechanisms of Action, and Side Effects

Anti-hypertensives

  • Used to treat hypertension
  • Mechanisms of action vary depending on the class of medication, but may include vasodilation, decreased cardiac output, or increased renal excretion of sodium and water
  • Side effects may include dizziness, headache, and cough 6
  • Drug interactions with antihypertensives can occur, including pharmacokinetic interactions that affect drug disposition and pharmacodynamic interactions that lead to synergy or antagonism of blood pressure lowering effects 6

Antibiotics, Anti-viral (Antiretroviral drugs), Analgesics, and Antihistamines

  • No specific information is available in the provided studies regarding the uses, mechanisms of action, and side effects of these medications

Medication Administration Calculations

  • No specific information is available in the provided studies regarding calculations for medication administration, including for Furosemide (Lasix), Dilantin (Phenytoin), and Ceftin (Cefuroxime)

Intravenous (IV) Flow Rate for 0.5% Dextrose

  • No specific information is available in the provided studies regarding the IV flow rate for 0.5% dextrose

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

How to take a comprehensive patient history.

Emergency nurse : the journal of the RCN Accident and Emergency Nursing Association, 2024

Research

A guide to taking a patient's history.

Nursing standard (Royal College of Nursing (Great Britain) : 1987), 2007

Research

Obtaining a "reasonably accurate" health history.

Plastic surgical nursing : official journal of the American Society of Plastic and Reconstructive Surgical Nurses, 1994

Research

Approaches to building rapport with patients.

Clinical medicine (London, England), 2021

Research

Drug Interactions with Antihypertensives.

Current hypertension reports, 2021

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Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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