Module 3 - PhLE

• Reactivity Factor for Bases:

  • Number of replaceable hydroxyl
  • Examples: NaOH = 1, Mg(OH)2 = 2, Al(OH)3 = 3
• Reactivity Factor for Salts:

  • Total positive (+) or negative (-) charges
  • Examples: NaCl = 1, Ca3(PO4)2 = 6, MgO = 2, NaSCN = 1, FeCl3 = 3
• Osmolarity is the total osmotic concentration of all solutes in a solution
• Van't Hoff factor of dissociation factor = number of species
• Three aspects:

  • Non-electrolytes: do not dissolve, 1 species
  • Strong electrolytes: 100% dissociation, 2 species
  • Weak electrolytes: less than 100% dissociation, 1.8 species
• Dilution:

  • Decrease of the solute concentration
  • Can be achieved by adding water or solvent
  • Formula: C1V1 = C2V2
• Concentration:

  • Increase of the solute concentration
  • Can be achieved by adding solute or drying the solution
• Alligation is an arithmetical method for mixing solutions with different percentage strengths
• Alligation Medial: Weighted Average

  • Concentration of Compound: Given
  • Amount of Compound: Unknown
  • Final Concentration: Unknown
• Alligation Alternate: Cross-Sub

  • Concentration of Compound: Given
  • Amount of Compound: Given
  • Final Concentration: Unknown
• IV Infusions are sterile, aqueous preparations administered intravenously in large volumes
• Uses:

  • Extend blood volume
  • Provide electrolytes, nutrients, and medications
• Indications:

  • Patients in critical care or infirmary
  • Dehydrated and malnourished
  • Patients prior to, during, and following surgery
• Forms:

  • Glass/plastic bottles
  • Collapsible plastic bag
  • SVP: Small Volume Parenteral (e.g., 50mL, 100mL)
  • LVP: Large Volume Parenteral (e.g., 250mL, 500mL, 1000mL)
• Rate of Flow Calculations:

  • Infusion time = volume of infusion (mL) / flow rate (mL/min or mL/hr)
  • Rate of flow (drops/min) = volume of infusion (mL) x drip set (drops/mL) / time (min)
• IV Admixtures are one or more sterile products mixed into an IV fluid for administration
• 3 Modes of Nutrition:

  • Oral Nutrition: by mouth
  • Enteral Nutrition: via tubes (NGT) to the stomach or small intestine
  • Parenteral Nutrition: via IV
• Caloric Requirement:

  • Kilocalorie (Kcal) = Calories
  • Steps:

  1. Compute caloric requirement using Harris-Benedict Equation and correct for activity/stress factors

  2. Compute protein requirements (0.8g/kg/d) and its caloric value

  3. Compute remaining calories (to be supplied by CHO and lipids)
• Harris Benedict Equation:

  • Basal energy expenditure (BEE) requirement
  • Total Daily Expenditure = BEE x activity factor x stress factor
  • Activity Factor:

  1.2: Sedentary

  1.375: Lightly Active

  1.55: Moderately Active

  1.725: Very Active

  1.9: Extremely Active
• TPN Composition and Caloric Values:

  • Dextrose (anhydrous) via oral: 4 kcal/g
  • Dextrose (hydrous) via IV: 3.4 kcal/g
  • Alcohol via oral: 7 kcal/g
  • Alcohol via IV: 5.6 kcal/g
  • Lipid: 9 kcal/g
  • Amino Acid: 4 kcal/g
  • Medium Chain Fatty Acid: 8.3 kcal/g
  • Glycerol: 4.3 kcal/g
  • 20% Fat Emulsion: 2 kcal/mL
  • 10% Fat Emulsion: 1.2 kcal/mL
• Discounts:

  • List Price: original price or trade price
  • Discounted Price (Net Cost): price after discount is applied
  • Selling Price = Cost + Gross Profit (% Mark Up)
• Proof Strength and Proof Gallons:

  • PS = 2 (% v/v alcohol)
  • Proof Gallon: taxable unit of alcohol
  • PG = wine gallon x % v/v
• Dispensing is the act of filling a prescription or doctor's order on the patient's chart by a validly registered pharmacist
• Important Administrative Orders related to dispensing:

  • DOH AO 62: prescribing requirements of RA 6675
  • DOH AO 63: dispensing requirements of RA 6675
  • DOH AO 55: labeling of product
  • DOH AO 56: licensing of establishment
• Prescription is a written order of a specific drug for a specific patient by a validly registered physician, dentist, or veterinarian

  • Can be written by a registered pharmacist based on telephone dictation by a physician
  • Serves as a professional relationship among prescribers, registered pharmacist, and patient
  • Terms: "prae"= before ; "scribe"= I write
• Parts of a prescription:

  1. Prescriber's information and signature

  2. Patient's information

  3. Superscription (Rx symbol)

  4. Inscription (medications)

  5. Subscription (instructions to the pharmacist)

  6. Transcription/Signa (instructions to the patient)

  7. Special Instructions
• Classification of prescriptions:

  • Compounded Prescription: requires mixing
  • Non-compounded Prescription: does not require mixing, can be prefabricated
  • New prescription: original prescription order filled for the first time
  • Refill Prescription: any repeat filling of an original prescription
  • Partial Filling: dispensing less than the number of units prescribed by the doctor
• Types of drugs:

  • Non-prescription or Over-the-Counter (OTC) Drugs: do not require prescription orders, bought off-the-shelf in stores
  • Prescription or Ethical Drugs: require prescription order, bought at the pharmacy, intended for one patient only
  • Dangerous Drugs:
  • List A: Prohibited Drugs (e.g., Opioids, Narcotics, Hallucinogens) and Regulated Drugs (e.g., Benzodiazepines, Barbiturates)
  • List B: Requires strict regulations due to addiction potential
• Years prescription is kept:

  • 1 year: Dangerous Drug Book
  • 2 years: Prescription Book
  • 5 years: Poison Book
• Prescription Errors:

  • Erroneous: errors in format
  • Violative: errors in brand name prominence
  • Impossible: errors in legibility or drug registration
• Incompatibilities when combining drugs:

  • Physiochemical Incompatibilities: changes in physical and chemical properties
  • Physical: insolubility, polymorphism, liquefaction
  • Chemical: redox, hydrolysis, acid-base reactions, photochemical oxidation, optical isomerism
• Therapeutic Incompatibilities:

  • Drug Interactions inside the body
  • Precipitant drug induces the interaction, Object drug is affected
  • Examples: Drug-Herb Interactions affecting drug concentrations
• St. John’s Wort (antidepressant, enzyme inducer) decreases serum concentration of digoxin
• Warfarin (anticoagulant) + G Herbs (garlic, ginger, ginko biloba; used as anticoagulant) results in an additive anticoagulant effect and increases the risk of bleeding
• Warfarin + Asian Ginseng decreases the anticoagulant effect of warfarin and increases the risk of thrombosis
• Benzodiazepines, Barbiturates (sedatives) + Valeria (sedative) leads to additive CNS depression (respiratory depression)
• Salbutamol (anti-asthma) + Lagundi (anti-cough) results in an additive bronchodilating effect (synergism)
• Tetracyclines/fluoroquinolones + Ca2+ rich diet (milk/dairy products) leads to chelation/complexation, decreasing the absorption of antibiotics and causing persistent infection
• MAO inhibitors + Tyramine rich foods (cheese, wine, beer, red meat, banana) inhibits MAO activity, leading to an increase in tyramine levels, norepinephrine release, and hypertension crisis
• Spironolactone (K-sparing diuretics) + Potassium (K) rich diet results in additive hyperkalemia