Lessons · Pharmacy · Quick reference
Pharmacy quick reference
40 topics, one line each, in the order Hone teaches them.
Hone is a place to practise a career, one idea a day. This sheet is the whole Pharmacy track at a glance: every idea it covers, in the order they are taught, one line each. It is a map rather than a lesson. Read opens the full explanation of an idea; Practise gives you a question on it. Both are free, and reading needs no account at all.
From a conversion to a filled prescription · Units and reading
the metric ladder: grams, milligrams, microgramsEvery step down the metric ladder multiplies by a thousand: 1 g = 1,000 mg, and 1 mg = 1,000 mcg. Read: The metric ladder: one step is a thousand · Practise the metric ladder: grams, milligrams, micrograms
millilitres, litres and the ccA litre is 1,000 millilitres, and a cubic centimetre, written cc, is exactly the same volume as a millilitre. Read: Millilitres, litres, and the cc · Practise millilitres, litres and the cc
pounds to kilogramsWeight-based orders are written in kilograms, and there are 2.2 pounds in a kilogram, so pounds divide by 2.2 to become kilograms. Read: Pounds on the chart, kilograms in the order · Practise pounds to kilograms
teaspoonfuls and tablespoonfuls in millilitresA teaspoonful is 5 mL, a tablespoonful is 15 mL and a fluid ounce is 30 mL, and the label always carries the millilitres. Read: Kitchen measures, written in millilitres · Practise teaspoonfuls and tablespoonfuls in millilitres
roman numerals on a scriptPrescribers still write quantities in roman numerals, and five letters cover almost all of them: i is 1, v is 5, x is 10, l is 50 and c is 100. Read: Roman numerals on a script · Practise roman numerals on a script
sig abbreviations in plain wordsThe sig is the directions in shorthand: po is by mouth, bid is twice a day, tid three times, qid four times, q6h every six hours, and prn as needed. Read: The sig, in plain words · Practise sig abbreviations in plain words
the parts of a prescriptionEvery prescription carries the same parts: the patient, the drug and its strength, the quantity to dispense, the sig, the refills, the date it was written and the prescriber. Read: The parts of a prescription · Practise the parts of a prescription
From a conversion to a filled prescription · Days' supply and quantity
how much to dispenseThe quantity is the dose multiplied by how many times a day, multiplied by how many days. Read: How much to dispense · Practise how much to dispense
how many days the bottle lastsDays' supply is the quantity dispensed divided by the amount used in one day. Read: How many days the bottle lasts · Practise how many days the bottle lasts
days' supply from an insulin vialA 10 mL vial labelled 100 units/mL holds 1,000 units, and the days' supply is those units divided by the units used in a day. Read: Days' supply from an insulin vial · Practise days' supply from an insulin vial
puffs in a canisterThe canister's label says how many actuations it holds, and the days' supply is that number divided by the puffs used in a day. Read: Puffs in a canister · Practise puffs in a canister
eye drops, at 20 drops to the millilitreUsing 20 drops per mL as the problem gives it, a bottle holds its millilitres times 20 drops, and the days' supply is those drops divided by the drops used in a day. Read: Eye drops, at 20 drops to the millilitre · Practise eye drops, at 20 drops to the millilitre
refills and the last fill dateThe refills written on a script are the fills AFTER the first one, and the days' supply added to the fill date gives the earliest the next one is due. Read: Refills, and when the next one is due · Practise refills and the last fill date
From a conversion to a filled prescription · Dose calculation
desired over have, times the quantityThe amount to give is what you want divided by what one unit holds, multiplied by the size of that unit: D / H x Q. Read: Desired over have, times the quantity · Practise desired over have, times the quantity
a liquid dose in millilitresReduce the stock to milligrams in one millilitre, then divide the milligrams wanted by that. Read: A liquid dose in millilitres · Practise a liquid dose in millilitres
a dose written in milligrams per kilogramA mg/kg order is a multiplication: the milligrams per kilogram the order gives, times the weight in kilograms. Read: A dose written in milligrams per kilogram · Practise a dose written in milligrams per kilogram
a child's dose, as the order writes itA child's dose is worked from the milligrams per kilogram the order gives and the child's weight, and from nothing else. Read: A child's dose, exactly as the order writes it · Practise a child's dose, as the order writes it
a dose from a percent strengthA percent strength written w/v is grams in 100 mL, and turning it into milligrams per millilitre is a multiplication by 10. Read: A dose out of a percent strength · Practise a dose from a percent strength
checking the answer by sizeBefore a number goes on a label, ask whether it should have come out bigger or smaller than the stock, and whether it is an amount a person could actually take. Read: Check the answer by size before you write it · Practise checking the answer by size
From a conversion to a filled prescription · Concentrations and dilutions
percent strength, weight in volumeA percent strength written w/v is the number of grams in every 100 mL of the liquid. Read: Percent strength: grams in a hundred millilitres · Practise percent strength, weight in volume
ratio strengthA ratio strength like 1:1000 means 1 gram in 1,000 mL, so the milligrams per millilitre are 1,000 divided by the number after the colon. Read: Ratio strength: one gram in so many millilitres · Practise ratio strength
C1V1 = C2V2Diluting adds liquid and adds no drug, so the strength times the volume before equals the strength times the volume after. Read: C1V1 = C2V2: the drug does not change · Practise C1V1 = C2V2
alligation: mixing a strong and a weakTo reach a strength in between two you have, the parts of each are the differences taken across the diagonal. Read: Alligation: mixing a strong one and a weak one · Practise alligation: mixing a strong and a weak
how much diluent to addThe diluent is the final volume less the volume of stock you started with, and it is never the whole final volume. Read: How much diluent to add · Practise how much diluent to add
parts per millionOne part per million is 1 gram in 1,000,000 mL, which is the same as 1 milligram in every litre. Read: Parts per million · Practise parts per million
From a conversion to a filled prescription · Compounding and IV
reducing and enlarging a formulaA formula is scaled by one factor: the amount you want divided by the amount the formula makes, applied to every ingredient without exception. Read: Reducing and enlarging a formula · Practise reducing and enlarging a formula
making a batch from a recipeA batch is a per-unit recipe multiplied by the number of units, weighed out in order and written down as it goes. Read: Making a batch from a recipe · Practise making a batch from a recipe
millilitres an hourThe rate on the pump is the volume divided by the time in hours. Read: Millilitres an hour · Practise millilitres an hour
how long the bag will runThe time is the volume divided by the rate, which is the millilitres-an-hour relationship turned around. Read: How long the bag will run · Practise how long the bag will run
drops a minuteDrops a minute is the millilitres an hour times the set's drop factor, divided by 60. Read: Drops a minute · Practise drops a minute
milliequivalents from milligramsMilliequivalents are milligrams divided by the equivalent weight, and the equivalent weight is always given to you by the problem. Read: Milliequivalents from milligrams · Practise milliequivalents from milligrams
reconstituting a powderThe powder in the vial has a volume of its own, so the diluent added is less than the final volume, and the strength after mixing is the drug divided by that final volume. Read: Reconstitution: the powder takes up room · Practise reconstituting a powder
From a conversion to a filled prescription · The counter
AWP, markup and the dispensing feeA price is the cost of what is dispensed, plus a markup worked on that cost, plus a flat fee for the work, and all three are given to you. Read: AWP, markup and the dispensing fee · Practise AWP, markup and the dispensing fee
the copay and the patient's shareThe copay is the patient's share, fixed by the plan, and what the plan pays is the price less that share. Read: The copay and what the plan pays · Practise the copay and the patient's share
a percent discountA discount is a percentage of the starting price taken off it, and what is paid is what is left. Read: A percent discount · Practise a percent discount
inventory turnoverTurnover is the cost of the goods sold in a year divided by the average value of the stock on the shelf. Read: Inventory turnover · Practise inventory turnover
expiry and beyond-use datesA manufacturer's expiry written as a month and a year runs to the LAST day of that month, and a beyond-use date is counted in days from the day the product was made or opened. Read: Expiry dates and beyond-use dates · Practise expiry and beyond-use dates
the order a prescription is filled inThe steps of a fill run in a fixed order, and the order is what catches a problem while it is still cheap to catch. Read: The order a prescription is filled in · Practise the order a prescription is filled in
the final checkThe last look compares the finished prescription against the original, item by item: the patient, the drug, the strength, the quantity and the directions. Read: The final check · Practise the final check
look-alike, sound-alike namesSome drug names look or sound so much like others that the only defence is a procedure: read the whole name, check the strength against what that drug is made in, and stop when something does not fit. Read: Look-alike, sound-alike · Practise look-alike, sound-alike names