PTCE cheat sheet

Levothyroxine is taken on an empty stomach 30 to 60 minutes before breakfast and separated from calcium, iron, and antacids by at least 4 hours.

Metformin (a biguanide) carries a boxed warning for lactic acidosis and is held around iodinated contrast when eGFR is 30 to 60 mL/min/1.73 m2.

Warfarin blocks vitamin K-dependent clotting factors, is monitored by INR, and is reversed with phytonadione (vitamin K).

Aminoglycosides (gentamicin, tobramycin) and vancomycin are nephrotoxic and ototoxic; serum trough levels guide dosing.

Rapid-acting insulins (lispro, aspart, glulisine) start in about 15 minutes and peak in 1 to 2 hours; unopened vials are refrigerated at 2 to 8 C and never frozen.

Amiodarone can cause thyroid dysfunction, pulmonary fibrosis, corneal microdeposits, and hepatotoxicity, so baseline and periodic monitoring is required.

ACE inhibitor adverse effects are dry cough, hyperkalemia, and angioedema; the class is contraindicated in pregnancy.

Methotrexate for non-oncologic disease is dosed once weekly; daily dosing causes fatal marrow toxicity, and leucovorin rescues folate toxicity.

Bioequivalent products share the same rate and extent of absorption; an AB rating in the Orange Book indicates therapeutic equivalence and substitutability.

Schedule II prescriptions cannot be refilled; patient-requested partial fills must be completed within 30 days (60 days for long-term care or terminally ill patients), or within 72 hours if the pharmacy cannot supply the balance.

Schedule III through V prescriptions may be refilled up to 5 times within 6 months of the date issued.

An oral emergency Schedule II prescription requires a written prescription from the prescriber within 7 days and is limited to the quantity needed for the emergency period.

Schedule II drugs are ordered on DEA Form 222 or through CSOS; theft or significant loss is reported on DEA Form 106 and destruction on DEA Form 41.

A biennial inventory is required: Schedule II counts must be exact, and controlled substance records are kept separately and retained for 2 years.

The Combat Methamphetamine Epidemic Act limits ephedrine and pseudoephedrine sales to 3.6 g per purchaser per day and 9 g per 30 days, kept behind the counter with a log and photo ID.

The Poison Prevention Packaging Act requires child-resistant containers unless the prescriber directs otherwise or the patient requests non-child-resistant packaging.

The DSCSA requires a product identifier on each package and verification of suspect product; transaction information and statements are retained for 6 years.

Abbreviations to avoid include U for units, QD and QOD, MS and MSO4 for morphine sulfate, naked decimals such as .5 mg, and trailing zeros such as 5.0 mg.

Tall-man lettering distinguishes look-alike names such as hydrOXYzine versus hydrALAZINE and glipiZIDE versus glyBURIDE.

USP 797 requires sterile compounding in an ISO Class 7 buffer area housing an ISO Class 5 primary engineering control, with beyond-use dates set by risk level, storage temperature, and preservative status.

USP 800 governs hazardous drugs: containment, closed-system transfer devices, two pairs of chemotherapy gloves, gowns, and a spill kit kept on hand.

Refrigerated drugs are stored at 2 to 8 C (36 to 46 F); controlled room temperature is 20 to 25 C (68 to 77 F); the freezer is -25 to -10 C.

High-alert medications such as insulin, heparin, opioids, and concentrated electrolytes require independent double checks and distinct storage.

A horizontal laminar airflow workbench is used for non-hazardous sterile compounding; a vertical Class II biological safety cabinet is used for hazardous drugs.

Medication errors are reported through nonpunitive systems such as ISMP MERP and FDA MedWatch and analyzed with root cause analysis.

A sentinel event is an unexpected occurrence involving death or serious harm; The Joint Commission expects a root cause analysis within 45 calendar days.

Days supply equals total quantity dispensed divided by the amount used per day; for insulin, divide total units dispensed by units used per day.

IV rate in mL/hr equals volume in mL divided by infusion time in hours; drops per minute equals (volume in mL x drop factor) divided by time in minutes.

C1V1 = C2V2 solves dilution problems; a 1:1000 ratio strength equals 0.1% and 1 mg/mL.

Percent weight-volume means grams of solute per 100 mL of solution; percent weight-weight means grams of solute per 100 g of product.

Cockcroft-Gault: CrCl (mL/min) = [(140 - age) x weight in kg] / (72 x serum creatinine), multiplied by 0.85 for females.

DEA check digit: add the 1st, 3rd, and 5th digits to twice the sum of the 2nd, 4th, and 6th digits; the last digit of that total equals the 7th digit of the DEA number.

Conversions: 1 kg = 2.2 lb, 1 tsp = 5 mL, 1 fl oz = 30 mL, 1 grain = 65 mg, 1 inch = 2.54 cm.

A complete prescription includes patient name and address, date, drug name with strength and dosage form, quantity, directions (sig), and prescriber signature.

Mosteller formula: BSA (m2) = square root of [(height in cm x weight in kg) / 3600].