<h1><strong>How to Calculate Drug Dose</strong></h1>
<p>These examples have been curated to show how to calculate drug dose for different drug formulations.</p>
<p><strong>1. Tablets and other fixed amount formulations</strong><br><br><strong>Example</strong>: Acetaminophen (Paracetamol) 500 mg, 20 tablets.<br><strong>DRUG_STRENGTH</strong> The denominator_unit is empty<br><strong>DRUG_EXPOSURE</strong> The quantity refers to number of pieces, e.g.tablets.<br><em>In the example</em>: 20<br><code>Ingredient dose= quantity x amount_value [amount_unit_concept_id]</code><br> Acetaminophen dose = 20 x 500mg = 10,000mg<br><br><strong>2. Puffs of an inhaler</strong><br><br><strong>Note</strong>: There is no difference to use case 1 above besides that the DRUG_STRENGTH table may put {actuat} in the denominator unit. In this case the strength is provided in the numerator.<br><strong>DRUG_STRENGTH</strong> The denominator_unit is {actuat}<br><strong>DRUG_EXPOSURE</strong> The quantity refers to the number of pieces, e.g.puffs<br><code>Ingredient dose= quantity x numerator_value [numerator_unit_concept_id]</code><br><br><strong>3. Quantified Drugs which are formulated as a concentration</strong><br><br><strong>Example</strong>: The Clinical Drug is Acetaminophen 250 mg/mL in a 5mL oral suspension. The Quantified Clinical Drug would have 1250 mg / 5 ml in the DRUG_STRENGTH table. Two suspensions are dispensed.<br><strong>DRUG_STRENGTH</strong> The denominator_unit is either mg or mL. The denominator_value might be different from 1.<br><strong>DRUG_EXPOSURE</strong> The quantity refers to a fraction or multiple of the pack.<br><em>In the example</em>: 2<br><code>Ingredient dose= quantity x numerator_value [numerator_unit_concept_id]</code><br><em>Acetaminophen dose</em> = 2 x 1250mg = 2500mg<br><br><strong>4. Drugs with the total amount provided in quantity, e.g.chemotherapeutics</strong><br><br><strong>Example</strong>: 42799258 “Benzyl Alcohol 0.1 ML/ML / Pramoxine hydrochloride 0.01 MG/MG Topical Gel” dispensed in a 1.25oz pack.<br><strong>DRUG_STRENGTH</strong> The denominator_unit is either mg or mL.<br><strong>Example</strong>: Benzyl Alcohol in mL and Pramoxine hydrochloride in mg<br><strong>DRUG_EXPOSURE</strong> The quantity refers to mL or g.<br><strong>Example</strong>: 1.25 x 30 <em>(conversion factor oz -> mL)</em> = 37<br><code>Ingredient dose= quantity x numerator_value [numerator_unit_concept_id]</code><br><em>Benzyl Alcohol dose</em> = 37 x 0.1mL = 3.7mL<br><em>Pramoxine hydrochloride dose</em> = 37 x 0.01mg x 1000 = 370mg<br><strong>Note</strong>: The analytical side should check the denominator in the DRUG_STRENGTH table. As mg is used for the second ingredient the factor 1000 will be applied to convert between g and mg.<br><br><strong>5. Compounded drugs</strong><br><br><strong>Example</strong>: Ibuprofen 20%/Piroxicam 1% Cream, 30ml in 5ml tubes.<br><strong>DRUG_STRENGTH</strong> We need entries for the ingredients of Ibuprofen and Piroxicam, probably with an amount_value of 1 and a unit of mg.<br><strong>DRUG_EXPOSURE</strong> The quantity refers to the total amount of the compound. Use one record in the DRUG_EXPOSURE table for each compound.<br><strong>Example</strong>: 20% Ibuprofen of 30ml = 6mL, 1% Piroxicam of 30ml = 0.3mL<br><code>Ingredient dose= Depends on the drugs involved: One of the use cases above.</code><em>Ibuprofen dose</em> = 6 x 1mg x 1000 = 6000mg<br><em>Piroxicam dose</em> = 0.3 x 1mg x 1000 = 300mg<br><strong>Note</strong>: The analytical side determines that the denominator for both ingredients in the DRUG_STRENGTH table is mg and applies the factor 1000 to convert between mL/g and mg.<br><br><strong>6. Drugs with the active ingredient released over time, e.g.patches</strong><br><br><strong>Example</strong>: Ethinyl Estradiol 0.000833 MG/HR / norelgestromin 0.00625 MG/HR Weekly Transdermal Patch<br><strong>DRUG_STRENGTH</strong> The denominator units refer to hour.<br><strong>Example</strong>: Ethinyl Estradiol 0.000833 mg/h / norelgestromin 0.00625 mg/h<br><strong>DRUG_EXPOSURE</strong> The quantity refers to the number of pieces.<br><strong>Example</strong>: 1 patch<br><code>Ingredient ra
