Pharmacology 3rd Partial Theory Exam Guide

Hemodynamics and Shock Management

• Cardiogenic Shock Treatment:

  • Primary interventions include the use of Vasopressors and treating the specific underlying etiology.

  • Fluid therapy is contraindicated if it is high and constant, as it can worsen the condition.

• Hemodynamic Formulas:

  • Blood Pressure ($BP$): $BP = CO \times PVR$ (Cardiac Output multiplied by Peripheral Vascular Resistance).

  • Cardiac Output ($CO$): $CO = SV \times HR$ (Stroke Volume multiplied by Heart Rate).

• Laboratory and Monitoring Values:

  • Lactate: The normal clinical value is <2\,mmol/L.

  • Delta $CO_2$ ($\Delta pCO_2$): The normal value for the difference between venous and arterial $CO_2$ should be <6\,mmHg.

• Hemorrhagic Shock Classification:

  • A loss of >40\% of total blood volume is classified as Type IV hemorrhagic shock.

• Fluid Resuscitation:

  • Parkland Formula: For burn patients, the first $50\%$ of the calculated fluid volume (solution) must be administered within the first $8\,hours$.

  • ROSE Protocol: This protocol is strictly followed in cases of Hypovolemic and Distributive shock, but it is not strictly followed in Cardiogenic shock.

• Renal Output/Volumetric Deficits:

  • Oliguria: Defined as a urine output of <400\,ml/day.

  • Anuria: Defined as a urine output of <100\,ml/day or, more specifically, <0.3\,ml/kg/hr.

Hypertension (HAS) and Cardiovascular Pharmacology

• Lifestyle Interventions and BP Reduction:

  • Weight Loss: Can lower blood pressure by a range of $5-20\,mmHg$.

  • Sodium Restriction: Limiting salt intake reduces blood pressure by $2-8\,mmHg$.

  • Dietary Recommendation: The current standard recommendation for patients with hypertension is the DASH diet.

• Pharmacological Guidelines:

  • First-line Treatments: Include ACE Inhibitors (IECA) and Calcium Antagonists.

  • Monotherapy Indications: Treatment with a single drug is indicated if blood pressure is <140/90\,mmHg and the patient is <65 years old, or if the patient is >80 years old.

  • Monotherapy Exclusions: Monotherapy is generally not the starting point if the patient has Type 2 Diabetes Mellitus (DMT2).

  • Elderly Patients: The drug of choice for hypertension in elderly patients is a Calcium Antagonist.

• Specific Drug Classes and Sites:

  • IECA (ACE Inhibitors): These drugs act primarily at the level of the Lung ($Pulmón$), where the Angiotensin-Converting Enzyme is highly prevalent.

  • Metoprolol: Identified in the study guide as a selective $\beta$ agent.

  • Fenilefrina: A selective $\alpha$ agonist used as a decongestant.

  • Diuretics and Glucose: Thiazides are the class of diuretics known to elevate blood glucose levels.

• Malignant Hypertension: This condition is strongly associated with the clinical finding of Papilledema.

Respiratory Pharmacology: Asthma

• Drug Classifications:

  • Salbutamol: Classified as a SABA (Short-Acting $\beta_2$-Agonist).

• Asthma Management Strategies:

  • MART Therapy (Maintenance and Reliever Therapy): This approach corresponds to Steps ($Escalones$) 1 through 5 of asthma management.

  • Track 1 Treatment: Consists of using low-dose ICS-Formoterol (GCI-Formoterol) as needed ($a\,demanda$).

• Physiological Complications of Overuse:

  • The excessive use of Salbutamol can result in the desensitization and endocytosis of the $\beta_2$ receptors.

Neurology: Epilepsy and Seizure Management

• Status Epilepticus (E.E.):

  • Operational Definition: A seizure event lasting >5\,min.

  • Pharmacological Intervention: Treatment must be initiated if the status lasts >5\,min.

  • Refractory Status Epilepticus: Management requires the ICU, Intubation, and Sedation.

• Pediatric and Developmental Syndromes:

  • West Syndrome: Typically presents in infants <1\,year old.

  • Lennox-Gastaut Syndrome: Typically occurs between the ages of $1-7\,years$.

  • Febrile Seizures: Atypical febrile seizures carry a $10-15\%$ risk of developing epilepsy later in life.

• Etiology and Contraindications:

  • Elderly Population: The most common cause of epilepsy in individuals >50 years old is a Cerebrovascular Accident (ACV).

  • Teratogenic Drugs: Valproic Acid ($Ac.\,Valproico$) and Phenytoin ($Fenito\acute{\imath}na$) are known to be teratogenic.

  • Adverse Reactions: Lamotrigine is specifically associated with Stevens-Johnson Syndrome ($Sx\,de\,Steven\,Jhonson$).

Renal Physiology and Diuretic Therapy

• Forces of Glomerular Filtration:

  • The forces that oppose filtration are the Hydrostatic Pressure ($Ph$) of the Bowman's capsule and the Oncotic Pressure ($PO$) of the Glomerular capillaries.

• Renal Processing and Volumes:

  • The kidneys process and reabsorb approximately $180\,L$ of fluid per day.

  • Only $1-2\%$ of the renal ultrafiltrate is ultimately excreted as urine.

• Site-Specific Reabsorption:

  • Approximately $60-67\%$ of Sodium ($Na^+$) reabsorption occurs in the Proximal Convoluted Tubule (TCP).

• Diuretics:

  • Loop Diuretics ($Diur\acute{e}tico\, de\, ASA$): Act on the thick ascending limb of the Loop of Henle ($Asa\, de\, Henley\, rama\, ascendente$). These are specifically recommended in cases of Severe Chronic Kidney Disease (ERC severa).

  • Thiazide Diuretics: Examples include Hydrochlorothiazide and Indapamide. Note that Spironolactone ($Espironolactona$) is NOT a thiazide (it is an aldosterone antagonist).

• Transport Mechanisms:

  • The SGLT2 transporters (Sodium-Glucose Linked Transporter 2) operate via a Symport ($Simporte$) mechanism.